Exhibit 10.21  AMENDED AND RESTATED PROMISSORY NOTE SECURED BY DEED OF TRUST (FORGIVABLE LOAN) Amended as of April 25,
2001   $500,000.00
  
  Mountain View, CaliforniaSeptember 27, 2000  For
value received, the undersigned, Warren C. Pratt (Employee) and Elizabeth
Pratt (collectively, Borrower) jointly and severally promise to pay to
SILICON GRAPHICS, INC., a Delaware corporation (SGI), or order, at 1600
Amphitheatre Parkway, Mountain View, California 94039-7311, or such other place
as SGI may designate in writing from time to time, in lawful money of the
United States of America, without abatement, demand, deduction, setoff or
counterclaim (except as provided in Paragraph 5), the principal sum of Five
Hundred Thousand and  00/100 Dollars
($500,000.00).  This Promissory Note
shall bear no interest, except as provided in Paragraph 4 below.  1.             Payments.  All outstanding principal and accrued
interest under this Promissory Note shall be due and payable on the Due Date
(as defined below); provided, however, that so long as Employee remains
employed by SGI on a regular and full-time basis, Borrowers obligation to pay
principal and interest under this Promissory Note shall be forgiven as follows:
(i) principal in the amount of Eight Thousand Three Hundred Thirty-Three and
33/100 ($8,333.33) per month shall be forgiven on October 22, 2000 and on the
twenty-second (22nd) day of each of the fifty-eight(58) calendar months
thereafter, and (ii) principal in the amount of Eight Thousand Three Hundred
Thirty-Three and 53/100 ($8,333.53) shall be forgiven on September 22,
2005.  Every payment received by SGI
with respect to this Promissory Note shall be applied as follows: first, to the
payment of any late charges; second, to the payment of accrued but unpaid interest;
and, third, to the payment of the outstanding principal balance of this
Promissory Note.  2.             Due
Date.  The Due Date shall be the
earlier of (i) the date of termination or cessation of SGIs employment of
Employee, involuntarily with cause, or (ii) September 22, 2005.The loan will be forgiven in full
if employment is terminated prior to the end of the five-year term (i) by SGI
other than for Cause (ii) by Employee for Good Reason or (iii) as a result of
death or Disability.  Defined terms not
otherwise set forth in this promissory note will have the meaning given to
those terms in our letter agreement dated April 25, 2001 relating to
forgiveable loan advances in an aggregate amount of up to $5,000,000 (the 2001
Letter Agreement).  3.             Purpose
of Loan.  Borrower acknowledges and
agrees that SGI is making this loan to Borrower for the express purpose of
facilitating Employees relocation to the area of SGIs corporate headquarters
located in Mountain View, California. 
Borrower represents and warrants to SGI that Borrower will use all
proceeds of this Promissory Note for purposes of purchasing  1 
   and improving Borrowers new principal residence
located at (address omitted)(New Residence).  4.             Default.  In the event that Borrower fails to timely
pay any amount or perform any other obligation of Borrower under this
Promissory Note, the Deed of Trust (as defined below), or any other agreement
or instrument now or hereafter executed by Borrower to evidence or secure the
performance of Borrowers obligations thereunder, SGI may, at its option,
declare the entire principal sum under this Promissory Note immediately due and
payable.  In the event that SGI
exercises this option, or the principal balance of this Promissory Note
otherwise becomes due and payable, all principal then outstanding under this
Promissory Note shall thereafter bear simple interest at the lesser of ten
percent (10%) per annum or the maximum rate permitted by law.  Failure to exercise this option shall not
constitute a waiver of SGIs right to exercise the same with respect to any
prior or subsequent defaults.  5.             Right
to Offset.  Borrower will have the
right to deduct or offset (1) amounts due but not yet paid by SGI to Borrower
under the 2001 Letter Agreement or (2) to the extent not paid by SGI when due,
the amount of the tax gross-up to be provided by SGI under paragraph 9 of this
Promissory Note, from or against amounts payable by Borrower to SGI under this
Promissory Note.  6.             Security.  Borrowers obligations under this Promissory
Note are secured by that certain Deed of Trust with Assignment of Rents of even
date herewith (Deed of Trust) encumbering the New Residence, as more
particularly described in the Deed of Trust.  7.             Due
on Sale.  The Deed of Trust provides
as follows:  If the trustor shall sell, convey or alienate said
property, or any part thereof, or any interest therein, or shall be divested of
his title or any interest therein in any manner or way, whether voluntarily or
involuntarily, without the written consent of the beneficiary being first had
and obtained, beneficiary shall have the right, at its option, except as
prohibited by law, to declare any indebtedness or obligations secured hereby,
irrespective of the maturity date specified in any not evidencing the same,
immediately due and payable.  8.             Attorneys
Fees.  In the event any legal action
or proceeding is required to enforce or interpret any provision of this
Promissory Note, Borrower shall pay to SGI upon demand all costs of collection
and reasonable attorneys fees incurred by SGI in connection therewith.  9.             Tax
Liability. The income tax liability to Borrower resulting from this
Promissory Note (including, imputed interest or the forgiveness of principal and
interest hereunder) shall be offset by the tax gross-up provided by SGI.  Borrower agrees that the non-interest
bearing nature of this Promissory Note is personal to Borrower and
non-transferable, and is conditioned upon the future performance of substantial  2 
   services by Employee.  Borrower
certifies to SGI that Borrower reasonably expects to itemize deductions for
each year that principal is outstanding under this Promissory Note.  10.           Miscellaneous.
 If any provision of this Promissory
Note shall be invalid or unenforceable for any reason, the same shall be
ineffective, but the remainder of this Promissory Note shall not be affected
thereby and shall remain in full force and effect.  Time is of the essence of each and every obligation of Borrower
and SGI hereunder.  Presentment and
demand for payment, notice of dishonor, protest and notice of protest are
hereby waived by Borrower and SGI with respect to amounts owed by each of them
respectively under the provisions of this Note.  If the due date for any payment under this Promissory Note falls
on a Saturday, Sunday or legal holiday, then such due date shall be extended to
the next business day.  None of the
terms or provisions of this Promissory Note may be waived, altered, modified or
amended except by a writing signed by SGI and Borrower.  The provisions of this Promissory Note shall
be governed by California law.  The covenants,
terms and conditions hereof shall bind the heirs, successors and assigns of
Borrower and shall inure to the benefit of the successors and assigns of SGI.  IN WITNESS WHEREOF, Borrower has executed this Promissory Note as of
the date first set forth above.   BORROWER:/s/  WARREN
  C. PRATTWARREN C. PRATT/s/  ELIZABETH
  PRATTELIZABETH PRATT  Amendment Agreed and Accepted by SGI:   By:
  /s/  SANDRA
  ESCHERSandra EscherSenior Vice President and General Counsel  3