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                                                                 EXHIBIT 10.11.3

                                                        [3Dfx Interactive, Inc.]


                                    GUARANTY

        THIS GUARANTY is made as of November 23, 1999, by 3Dfx INTERACTIVE, INC.
("Guarantor"), in favor of BANK ONE, TEXAS, N.A., a national banking
association, as agent for Lenders, as such term is defined in the Credit
Agreement described below (in such capacity "Agent").

                                    RECITALS:

        1.   STB System, Inc., a Texas corporation ("Borrower") executed: (i) in
favor of Bank One, Texas, N.A. that certain promissory note dated as of January
30, 1998, payable to the order of Bank One, Texas, N.A. in the aggregate
principal amount of $15,000,000; (ii) in favor of Sanwa Business Credit
Corporation that certain promissory note dated as of January 30, 1998, payable
to the order of Sanwa Business Credit Corporation in the aggregate principal
amount of $15,000,000; and (iii) in favor of Comerica Bank - California, that
certain promissory note dated as of January 30, 1998, payable to the order of
Comerica Bank - California in the aggregate principal amount of $10,000,000
(such promissory notes, as from time to time amended, and all promissory notes
given in substitution, renewal or extension therefore or thereof, in whole or in
part, being herein collectively called the "Note").

        2.   The Note was executed pursuant to a Credit Agreement dated as of
November 21, 1997, (herein, as from time to time amended, supplemented or
restated, called the "Credit Agreement"), by and between Borrower, Agent and
Lenders, pursuant to which Lenders have agreed to advance funds to Borrower
under the Note.

        3.   It is a condition precedent to Lenders' obligations to advance
funds pursuant to the Credit Agreement that Guarantor shall execute and deliver
to Agent a satisfactory guaranty of Borrower's obligations under the Note and
the Credit Agreement.

        4.   Guarantor owns directly, or indirectly through one or more
subsidiaries, one hundred percent (100%) of the outstanding shares of capital
stock of Borrower.

        5.   Borrower, Guarantor, and the other direct and indirect subsidiaries
of Guarantor are mutually dependent on each other in the conduct of their
respective businesses, with the credit needed from time to time by each often
being provided by another or by means of financing obtained by one such
affiliate with the support of the others for their mutual benefit and the
ability of each to obtain such financing being dependent on the successful
operations of the others.

        6.   The board of directors of Guarantor has determined that Guarantor's
execution, delivery and performance of this Guaranty may reasonably be expected
to benefit Guarantor, directly or indirectly, and are in the best interests of
Guarantor.


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        NOW, THEREFORE, in consideration of the premises, of the benefits which
will inure to Guarantor from Lenders' advances of funds to Borrower under the
Credit Agreement, and of Ten Dollars and other good and valuable consideration,
the receipt and sufficiency of all of which are hereby acknowledged, and in
order to induce Lenders to advance funds under the Credit Agreement, Guarantor
hereby agrees with Agent, for the benefit of Agent and Lenders as follows:


                                   AGREEMENTS

        Section 1. Definitions. Reference is hereby made to the Credit Agreement
for all purposes. All terms used in this Guaranty which are defined in the
Credit Agreement and not otherwise defined herein shall have the same meanings
when used herein. All references herein to any Obligation Document, Loan
Document, or other document or instrument refer to the same as from time to time
amended, supplemented or restated. As used herein the following terms shall have
the following meanings:

        "Agent" means the Person who, at the time in question, is the "Agent"
under the Credit Agreement. Whenever there is only one Lender under the Credit
Agreement, "Agent" shall also refer to such Lender in such capacity as the only
Lender.

        "Lenders" means Bank One, Texas, N.A. and all other Persons who at any
time are "Lenders" under the Credit Agreement.

        "Obligations" means collectively all of the indebtedness, obligations,
and undertakings which are guaranteed by Guarantor and described in subsections
(a) and (b) of Section 2.

        "Obligation Documents" means this Guaranty, the Note, the Credit
Agreement, the Loan Documents, all other documents and instruments under, by
reason of which, or pursuant to which any or all of the Obligations are
evidenced, governed, secured, or otherwise dealt with, and all other documents,
instruments, agreements, certificates, legal opinions and other writings
heretofore or hereafter delivered in connection herewith or therewith.

        "Obligors" means Borrower, Guarantor and any other endorsers, guarantors
or obligors, primary or secondary, of any or all of the Obligations.

        "Security" means any rights, properties, or interests of Agent or
Lenders, under the Obligation Documents or otherwise, which provide recourse or
other benefits to Agent or Lenders in connection with the Obligations or the
non-payment or non-performance thereof, including collateral (whether real or
personal, tangible or intangible) in which Agent or Lenders have rights under or
pursuant to any Obligation Documents, guaranties of the payment or performance
of any Obligation, bonds, surety agreements, keep-well agreements, letters of
credit, rights of subrogation, rights of offset, and rights pursuant to which
other claims are subordinated to the Obligations.



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        Section 2. Guaranty.

        (a) Guarantor hereby irrevocably, absolutely, and unconditionally
guarantees to Agent and each Lender the prompt, complete, and full payment when
due, and no matter how the same shall become due, of:

             (i) the Note, including all principal, all interest thereon and all
        other sums payable thereunder; and

             (ii) All other sums payable under the other Obligation Documents,
        whether for principal, interest, fees or otherwise; and

             (iii) Any and all other indebtedness or liabilities which Borrower
        may at any time owe to Agent or any Lender, whether incurred heretofore
        or hereafter or concurrently herewith, voluntarily or involuntarily,
        whether owed alone or with others, whether fixed, contingent, absolute,
        inchoate, liquidated or unliquidated, whether such indebtedness or
        liability arises by notes, discounts, overdrafts, open account
        indebtedness or in any other manner whatsoever, and including interest,
        attorneys' fees and collection costs as may be provided by law or in any
        instrument evidencing any such indebtedness or liability.

Without limiting the generality of the foregoing, Guarantor's liability
hereunder shall extend to and include all post-petition interest, expenses, and
other duties and liabilities of Borrower described above in this subsection (a),
or below in the following subsection (b), which would be owed by Borrower but
for the fact that they are unenforceable or not allowable due to the existence
of a bankruptcy, reorganization, or similar proceeding involving Borrower.

        (b) Guarantor hereby irrevocably, absolutely, and unconditionally
guarantees to Agent and each Lender the prompt, complete and full performance,
when due, and no matter how the same shall become due, of all obligations and
undertakings of Borrower to Agent or such Lender under, by reason of, or
pursuant to any of the Obligation Documents.

        (c) If Borrower shall for any reason fail to pay any Obligation, as and
when such Obligation shall become due and payable, whether at its stated
maturity, as a result of the exercise of any power to accelerate, or otherwise,
Guarantor will, forthwith upon demand by Agent, pay such Obligation in full to
Agent for the benefit of Agent or the Lender to whom such Obligation is owed. If
Borrower shall for any reason fail to perform promptly any Obligation, Guarantor
will, forthwith upon demand by Agent, cause such Obligation to be performed or,
if specified by Agent, provide sufficient funds, in such amount and manner as
Agent shall in good faith determine, for the prompt, full and faithful
performance of such Obligation by Agent or such other Person as Agent shall
designate.

        (d) If either Borrower or Guarantor fails to pay or perform any
Obligation as described in the immediately preceding subsections (a), (b), or
(c) Guarantor will incur the



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additional obligation to pay to Agent, and Guarantor will forthwith upon demand
by Agent pay to Agent, the amount of any and all reasonable expenses, including
fees and disbursements of Agent's counsel and of any experts or agents retained
by Agent, which Agent may incur as a result of such failure.

        (e) As between Guarantor and Agent or Lenders, this Guaranty shall be
considered a primary and liquidated liability of Guarantor.

        Section 3. Unconditional Guaranty.

        (a) No action which Agent or any Lender may take or omit to take in
connection with any of the Obligation Documents, any of the Obligations (or any
other indebtedness owing by Borrower to Agent or any Lender), or any Security,
and no course of dealing of Agent or any Lender with any Obligor or any other
Person, shall release or diminish Guarantor's obligations, liabilities,
agreements or duties hereunder, affect this Guaranty in any way, or afford
Guarantor any recourse against Agent or any Lender, regardless of whether any
such action or inaction may increase any risks to or liabilities of Agent or any
Lender or any Obligor or increase any risk to or diminish any safeguard of any
Security. Without limiting the foregoing, Guarantor hereby expressly agrees that
Agent and Lenders may, from time to time, without notice to or the consent of
Guarantor, do any or all of the following:

             (i) Amend, change or modify, in whole or in part, any one or more
        of the Obligation Documents and give or refuse to give any waivers or
        other indulgences with respect thereto.

             (ii) Neglect, delay, fail, or refuse to take or prosecute any
        action for the collection or enforcement of any of the Obligations, to
        foreclose or take or prosecute any action in connection with any
        Security or Obligation Document, to bring suit against any Obligor or
        any other Person, or to take any other action concerning the Obligations
        or the Obligation Documents.

             (iii) Accelerate, change, rearrange, extend, or renew the time,
        rate, terms, or manner for payment or performance of any one or more of
        the Obligations (whether for principal, interest, fees, expenses,
        indemnifications, affirmative or negative covenants, or otherwise).

             (iv) Compromise or settle any unpaid or unperformed Obligation or
        any other obligation or amount due or owing, or claimed to be due or
        owing, under any one or more of the Obligation Documents.

             (v) Take, exchange, amend, eliminate, surrender, release, or
        subordinate any or all Security for any or all of the Obligations,
        accept additional or substituted Security therefor, and perfect or fail
        to perfect Agent's or Lenders' rights in any or all Security.



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             (vi) Discharge, release, substitute or add Obligors.

             (vii) Apply all monies received from Obligors or others, or from
        any Security for any of the Obligations, as Agent or Lenders may
        determine to be in their best interest, without in any way being
        required to marshal Security or assets or to apply all or any part of
        such monies upon any particular Obligations.

        (b) No action or inaction of any Obligor or any other Person, and no
change of law or circumstances, shall release or diminish Guarantor's
obligations, liabilities, agreements, or duties hereunder, affect this Guaranty
in any way, or afford Guarantor any recourse against Agent or any Lender.
Without limiting the foregoing, the obligations, liabilities, agreements, and
duties of Guarantor under this Guaranty shall not be released, diminished,
impaired, reduced, or affected by the occurrence of any or all of the following
from time to time, even if occurring without notice to or without the consent of
Guarantor:

             (i) Any voluntary or involuntary liquidation, dissolution, sale of
        all or substantially all assets, marshaling of assets or liabilities,
        receivership, conservatorship, assignment for the benefit of creditors,
        insolvency, bankruptcy, reorganization, arrangement, or composition of
        any Obligor or any other proceedings involving any Obligor or any of the
        assets of any Obligor under laws for the protection of debtors, or any
        discharge, impairment, modification, release, or limitation of the
        liability of, or stay of actions or lien enforcement proceedings
        against, any Obligor, any properties of any Obligor, or the estate in
        bankruptcy of any Obligor in the course of or resulting from any such
        proceedings.

             (ii) The failure by Agent or any Lender to file or enforce a claim
        in any proceeding described in the immediately preceding subsection (I)
        or to take any other action in any proceeding to which any Obligor is a
        party.

             (iii) The release by operation of law of any Obligor from any of
        the Obligations or any other obligations to Agent or any Lender.

             (iv) The invalidity, deficiency, illegality, or unenforceability of
        any of the Obligations or the Obligation Documents, in whole or in part,
        any bar by any statute of limitations or other law of recovery on any of
        the Obligations, or any defense or excuse for failure to perform on
        account of force majeure, act of God, casualty, impossibility,
        impracticability, or other defense or excuse whatsoever.

             (v) The failure of any Obligor or any other Person to sign any
        guaranty or other instrument or agreement within the contemplation of
        any Obligor, Agent or any Lender.

             (vi) The fact that Guarantor may have incurred directly part of the
        Obligations or is otherwise primarily liable therefor.



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             (vii) Without limiting any of the foregoing, any fact or event
        (whether or not similar to any of the foregoing) which in the absence of
        this provision would or might constitute or afford a legal or equitable
        discharge or release of or defense to a guarantor or surety other than
        the actual payment and performance by Guarantor under this Guaranty.

        (c) Agent and Lenders may invoke the benefits of this Guaranty before
pursuing any remedies against any Obligor or any other Person and before
proceeding against any Security now or hereafter existing for the payment or
performance of any of the Obligations. Agent and Lenders may maintain an action
against Guarantor on this Guaranty without joining any other Obligor therein and
without bringing a separate action against any other Obligor.

        (d) If any payment to Agent or any Lender by any Obligor is held to
constitute a preference or a voidable transfer under applicable state or federal
laws, or if for any other reason Agent or any Lender is required to refund such
payment to the payor thereof or to pay the amount thereof to any other Person,
such payment to Agent or such Lender shall not constitute a release of Guarantor
from any liability hereunder, and Guarantor agrees to pay such amount to Agent
or such Lender on demand and agrees and acknowledges that this Guaranty shall
continue to be effective or shall be reinstated, as the case may be, to the
extent of any such payment or payments. Any transfer by subrogation which is
made as contemplated in [Section 6] prior to any such payment or payments shall
(regardless of the terms of such transfer) be automatically voided upon the
making of any such payment or payments, and all rights so transferred shall
thereupon revert to and be vested in Agent and Lenders.

        (e) This is a continuing guaranty and shall apply to and cover all
Obligations and renewals and extensions thereof and substitutions therefor from
time to time.

        Section 4. Waiver. Guarantor hereby waives, with respect to the
Obligations, this Guaranty, and the other Obligation Documents:

        (a) notice of the incurrence of any Obligation by Borrower, and notice
of any kind concerning the assets, liabilities, financial condition,
creditworthiness, businesses, prospects, or other affairs of Borrower (it being
understood and agreed that: (I) Guarantor shall take full responsibility for
informing itself of such matters, (ii) neither Agent nor any Lender shall have
any responsibility of any kind to inform Guarantor of such matters, and (iii)
Agent and Lenders are hereby authorized to assume that Guarantor, by virtue of
its relationships with Borrower which are independent of this Guaranty, has full
and complete knowledge of such matters whenever Lenders extend credit to
Borrower or take any other action which may change or increase Guarantor's
liabilities or losses hereunder).

        (b) notice that Agent, any Lender, any Obligor, or any other Person has
taken or omitted to take any action under any Obligation Document or any other
agreement or instrument relating thereto or relating to any Obligation.



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        (c) notice of acceptance of this Guaranty and all rights of Guarantor
under Section 34.02 of the Texas Business and Commerce Code.

        (d) demand, presentment for payment, and notice of demand, dishonor,
nonpayment, or nonperformance.

        (e) notice of intention to accelerate, notice of acceleration, protest,
notice of protest, notice of any exercise of remedies (as described in the
following Section 5 or otherwise), and all other notices of any kind whatsoever.

        Section 5. Exercise of Remedies. Agent and each Lender shall have the
right to enforce, from time to time, in any order and at Agent's or such
Lender's sole discretion, any rights, powers and remedies which Agent or such
Lender may have under the Obligation Documents or otherwise, including judicial
foreclosure, the exercise of rights of power of sale, the taking of a deed or
assignment in lieu of foreclosure, the appointment of a receiver to collect
rents, issues and profits, the exercise of remedies against personal property,
or the enforcement of any assignment of leases, rentals, oil or gas production,
or other properties or rights, whether real or personal, tangible or intangible;
and Guarantor shall be liable to Agent and each Lender hereunder for any
deficiency resulting from the exercise by Agent or any Lender of any such right
or remedy even though any rights which Guarantor may have against Borrower or
others may be destroyed or diminished by exercise of any such right or remedy.
No failure on the part of Agent or any Lender to exercise, and no delay in
exercising, any right hereunder or under any other Obligation Document shall
operate as a waiver thereof; nor shall any single or partial exercise of any
right preclude any other or further exercise thereof or the exercise of any
other right. The rights, powers and remedies of Agent and each Lender provided
herein and in the other Obligation Documents are cumulative and are in addition
to, and not exclusive of, any other rights, powers or remedies provided by law
or in equity. The rights of Agent and each Lender hereunder are not conditional
or contingent on any attempt by Agent or any Lender to exercise any of its
rights under any other Obligation Document against any Obligor or any other
Person.

        Section 6. Limited Subrogation. Until all of the Obligations have been
paid and performed in full Guarantor shall have no right to exercise any right
of subrogation, reimbursement, indemnity, exoneration, contribution or any other
claim which it may now or hereafter have against or to any Obligor or any
Security in connection with this Guaranty (including any right of subrogation
under Section 34.04 of the Texas Business and Commerce Code), and Guarantor
hereby waives any rights to enforce any remedy which Guarantor may have against
Borrower and any right to participate in any Security until such time. If any
amount shall be paid to Guarantor on account of any such subrogation or other
rights, any such other remedy, or any Security at any time when all of the
Obligations and all other expenses guaranteed pursuant hereto shall not have
been paid in full, such amount shall be held in trust for the benefit of Agent,
shall be segregated from the other funds of Guarantor and shall forthwith be
paid over to Agent to be held by Agent as collateral for, or then or at any time
thereafter applied in whole or in part by Agent against, all or any portion of
the Obligations, whether matured or unmatured, in such order as Agent shall
elect. If Guarantor shall make payment to Agent of all or any


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portion of the Obligations and if all of the Obligations shall be finally paid
in full, Agent will, at Guarantor's request and expense, execute and deliver to
Guarantor (without recourse, representation or warranty) appropriate documents
necessary to evidence the transfer by subrogation to Guarantor of an interest in
the Obligations resulting from such payment by Guarantor; provided that such
transfer shall be subject to Section 3(d) above and that without the consent of
Agent (which Agent may withhold in its reasonable discretion) Guarantor shall
not have the right to be subrogated to any claim or right against any Obligor
which has become owned by Agent or any Lender, whose ownership has otherwise
changed in the course of enforcement of the Obligation Documents, or which Agent
otherwise has released or wishes to release from its Obligations.

        Section 7. Successors and Assigns. Guarantor's rights or obligations
hereunder may not be assigned or delegated, but this Guaranty and such
obligations shall pass to and be fully binding upon the successors of Guarantor,
as well as Guarantor. This Guaranty shall apply to and inure to the benefit of
Agent and Lenders and their successors or assigns. Without limiting the
generality of the immediately preceding sentence, Agent and each Lender may
assign, grant a participation in, or otherwise transfer any Obligation held by
it or any portion thereof, and Agent and each Lender may assign or otherwise
transfer its rights or any portion thereof under any Obligation Document, to any
other Person, and such other Person shall thereupon become vested with all of
the benefits in respect thereof granted to Agent or such Lender hereunder unless
otherwise expressly provided by Agent or such Lender in connection with such
assignment or transfer.

        Section 8. Subordination and Offset. Guarantor hereby subordinates and
makes inferior to the Obligations any and all indebtedness now or at any time
hereafter owed by Borrower to Guarantor. Guarantor agrees that after the
occurrence of any Default or Event of Default it will neither permit Borrower to
repay such indebtedness or any part thereof nor accept payment from Borrower of
such indebtedness or any part thereof without the prior written consent of Agent
and Lenders. If Guarantor receives any such payment without the prior written
consent of Agent and Lenders, the amount so paid shall be held in trust for the
benefit of Lenders, shall be segregated from the other funds of Guarantor, and
shall forthwith be paid over to Agent to be held by Agent as collateral for, or
then or at any time thereafter applied in whole or in part by Agent against, all
or any portions of the Obligations, whether matured or unmatured, in such order
as Agent shall elect. Guarantor hereby grants to Lenders a right of offset to
secure the payment of the Obligations and Guarantor's obligations and
liabilities hereunder, which right of offset shall be upon any and all monies,
securities and other property (and the proceeds therefrom) of Guarantor now or
hereafter held or received by or in transit to Agent or any Lender from or for
the account of Guarantor, whether for safekeeping, custody, pledge,
transmission, collection or otherwise, and also upon any and all deposits
(general or special), credits and claims of Guarantor at any time existing
against Agent or any Lender. Upon the occurrence of any Default or Event of
Default Agent and each Lender is hereby authorized at any time and from time to
time, without notice to Guarantor, to offset, appropriate and apply any and all
items hereinabove referred to against the Obligations and Guarantor's
obligations and liabilities hereunder irrespective of whether or not Agent or
such Lender shall have made any demand



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under this Guaranty and although such obligations and liabilities may be
contingent or unmatured. Agent and each Lender agrees promptly to notify
Guarantor after any such offset and application made by Agent or such Lender,
provided that the failure to give such notice shall not affect the validity of
such offset and application. The rights of Agent and each Lender under this
section are in addition to, and shall not be limited by, any other rights and
remedies (including other rights of offset) which Agent and Lenders may have.

        Section 9. Representations and Warranties. Guarantor hereby represents
and warrants to Agent and each Lender as follows:

        (a) The Recitals at the beginning of this Guaranty are true and correct
in all respects.

        (b) Guarantor is a corporation duly organized, validly existing and in
good standing under the laws of the state of its incorporation as set forth in
the Recitals to this Guaranty; and Guarantor has all requisite power and
authority to execute, deliver and perform this Guaranty.

        (c) The execution, delivery and performance by Guarantor of this
Guaranty have been duly authorized by all necessary corporate action and do not
and will not contravene its certificate or articles of incorporation or bylaws.

        (d) The execution, delivery and performance by Guarantor of this
Guaranty do not and will not contravene any law or governmental regulation or
any contractual restriction binding on or affecting Guarantor or any of its
Affiliates or properties, and do not and will not result in or require the
creation of any lien, security interest or other charge or encumbrance upon or
with respect to any of its properties.

        (e) To the best of Guarantor's knowledge, no authorization or approval
or other action by, and no notice to or filing with, any governmental authority
or other regulatory body or third party is required for the due execution,
delivery and performance by Guarantor of this Guaranty.

        (f) This Guaranty is a legal, valid and binding obligation of Guarantor,
enforceable against Guarantor in accordance with its terms except as limited by
bankruptcy, insolvency or similar laws of general application relating to the
enforcement of creditors' rights.

        (g) There is no action, suit or proceeding pending or, to the knowledge
of Guarantor, threatened against or otherwise affecting Guarantor before any
court, arbitrator or governmental department, commission, board, bureau, agency
or instrumentality which may materially and adversely affect Guarantor's
financial condition or its ability to perform its obligations hereunder.

        (h) The direct or indirect value of the consideration received and to be
received by Guarantor in connection herewith is reasonably worth at least as
much as the liability and obligations of Guarantor hereunder, and the incurrence
of such liability and obligations in return for such consideration may
reasonably be expected to benefit Guarantor, directly or indirectly.



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        (i) Guarantor's capital is adequate for the businesses in which
Guarantor is engaged and intends to be engaged. Guarantor has not incurred
(whether hereby or otherwise), nor does Guarantor intend to incur or believe
that it will incur, debts which will be beyond its ability to pay as such debts
mature.

        (j) All balance sheets, earning statements, financial data and other
information concerning Guarantor which have been furnished to Agent and each
Lender to induce it to accept this Guaranty (or otherwise furnished to Agent and
each Lender in connection with the transactions contemplated hereby or
associated herewith) fairly represent the financial condition of Guarantor as of
the dates and the results of Guarantor's operations for the periods for which
the same are furnished. None of such balance sheets, earnings and cash flow
statements, financial data and other information contains any untrue statement
of a material fact or omits to state any material fact which is necessary to
make any statements contained therein not misleading.

        Section 10. No Oral Change. No amendment of any provision of this
Guaranty shall be effective unless it is in writing and signed by Guarantor and
Lenders, and no waiver of any provision of this Guaranty, and no consent to any
departure by Guarantor therefrom, shall be effective unless it is in writing and
signed by Lenders, and then such waiver or consent shall be effective only in
the specific instance and for the specific purpose for which given.

        Section 11. Invalidity of Particular Provisions. If any term or
provision of this Guaranty shall be determined to be illegal or unenforceable
all other terms and provisions hereof shall nevertheless remain effective and
shall be enforced to the fullest extent permitted by applicable law.

        Section 12. Headings and References. The headings used herein are for
purposes of convenience only and shall not be used in construing the provisions
hereof. The words "this Guaranty," "this instrument," "herein," "hereof,"
"hereby" and words of similar import refer to this Guaranty as a whole and not
to any particular subdivision unless expressly so limited. The phrases "this
section" and "this subsection" and similar phrases refer only to the
subdivisions hereof in which such phrases occur. The word "or" is not exclusive,
and the word "including" (in its various forms) means "including without
limitation". Pronouns in masculine, feminine and neuter genders shall be
construed to include any other gender, and words in the singular form shall be
construed to include the plural and vice versa, unless the context otherwise
requires.

        Section 13. Term. This Guaranty shall be irrevocable until all of the
Obligations have been completely and finally paid and performed, no Lender has
any obligation to make any loans or other advances to Borrower, and all
obligations and undertakings of Borrower under, by reason of, or pursuant to the
Obligation Documents have been completely performed, and this Guaranty is
thereafter subject to reinstatement as provided in Section 3(d). All extensions
of credit and financial accommodations heretofore or hereafter made by Agent or
Lenders to Borrower shall be conclusively presumed to have been made in
acceptance hereof and in reliance hereon.



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        Section 14. Notices. Any notice or communication required or permitted
hereunder shall be given in writing, sent by personal delivery, by telecopy, by
delivery service with proof of delivery, or by registered or certified United
States mail, postage prepaid, addressed to the appropriate party as follows:

        To Guarantor:        3Dfx Interactive, Inc.
                             c/o: STB Systems, Inc.
                             Attention: Bryan F. Keyes
                             3400 Waterview
                             Richardson, TX   75080
                             Fax: (972) 680-7153

        To Agent:            1717 Main Street
                             Dallas, Texas 75201
                             Attn:  Richard L. Rogers
                             Fax: (214) 296-2492

or to such other address or to the attention of such other individual as
hereafter shall be designated in writing by the applicable party sent in
accordance herewith. Any such notice or communication shall be deemed to have
been given (a) in the case of personal delivery or delivery service, as of the
date of first attempted delivery at the address or in the manner provided
herein, (b) in the case of telecopy, upon receipt, or (b) in the case of
registered or certified United States mail, three days after deposit in the
mail.

        Section 15. Limitation on Interest. Agent, Lenders and Guarantor intend
to contract in strict compliance with applicable usury law from time to time in
effect, and the provisions of the Credit Agreement limiting the interest for
which Guarantor is obligated are expressly incorporated herein by reference.

        Section 16. Loan Document. This Guaranty is a Loan Document, as defined
in the Credit Agreement, and is subject to the provisions of the Credit
Agreement governing Loan Documents. Guarantor hereby ratifies, confirms and
approves the Credit Agreement and the other Loan Documents and, in particular,
any provisions thereof which relate to Guarantor.

        Section 17. Counterparts. This Guaranty may be executed in any number of
counterparts, each of which when so executed shall be deemed to constitute one
and the same Guaranty.

        SECTION 18. GOVERNING LAW. THIS GUARANTY IS TO BE PERFORMED IN THE STATE
OF TEXAS AND SHALL BE GOVERNED BY AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH
THE LAWS OF SUCH STATE WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAW.
GUARANTOR HEREBY IRREVOCABLY SUBMITS ITSELF TO THE EXCLUSIVE JURISDICTION OF THE
STATE AND FEDERAL COURTS OF TEXAS. IN FURTHERANCE OF THE


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<PAGE>   12

FOREGOING, GUARANTOR HEREBY IRREVOCABLY DESIGNATES AND APPOINTS CT CORPORATION
SYSTEMS, AS AGENT OF GUARANTOR TO RECEIVE SERVICE OF ALL PROCESS BROUGHT AGAINST
GUARANTOR WITH RESPECT TO ANY SUCH PROCEEDING IN ANY SUCH COURT IN TEXAS, SUCH
SERVICE BEING HEREBY ACKNOWLEDGED BY GUARANTOR TO BE EFFECTIVE AND BINDING
SERVICE IN EVERY RESPECT. COPIES OF ANY SUCH PROCESS SO SERVED SHALL ALSO, IF
PERMITTED BY LAW, BE SENT BY REGISTERED MAIL TO GUARANTOR AT ITS ADDRESS SET
FORTH ABOVE, BUT THE FAILURE OF GUARANTOR TO RECEIVE SUCH COPIES SHALL NOT
AFFECT IN ANY WAY THE SERVICE OF SUCH PROCESS AS AFORESAID. NOTHING HEREIN SHALL
AFFECT THE RIGHT OF AGENT TO SERVE PROCESS IN ANY OTHER MANNER PERMITTED BY LAW.



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<PAGE>   13

        IN WITNESS WHEREOF, Guarantor has executed and delivered this Guaranty
as of the date first written above.



                                       3DFX INTERACTIVE, INC.

                                       By:  /s/  AUTHORIZED OFFICER
                                          ------------------------------------
                                          Name:
                                          Title: