Exhibit 10.75

RACKABLE SYSTEMS, INC.

THIRD AMENDMENT TO EMPLOYMENT AGREEMENT

This THIRD AMENDMENT TO THE EMPLOYMENT AGREEMENT (the “Third Amendment”) dated
December 23, 2008 (the “Effective Date”) is executed by and between Rackable
Systems, Inc., a Delaware corporation (the “Company”), and Maurice Leibenstern
(the “Executive”). The Company and the Executive are each individually referred
to in this Amendment as a “Party” and are collectively referred to in this
Amendment as the “Parties.”

RECITALS

A. Executive and the Company have entered into an Employment Agreement dated
August, 2007 (the “Employment Agreement”).

B. The Executive and the Company are parties to a First Amendment and a Second
Amendment to the Employment Agreement dated September 19, 2007 and November 17,
2008, respectively.

C. The Parties desire to further amend the Employment Agreement as follows.

AGREEMENT

In consideration of the mutual promises and covenants set forth in this Third
Amendment, the receipt and sufficiency of which are hereby acknowledged, the
Parties agree as follows:

1. Amendment to Employment Agreement. The Parties agree that upon the Effective
Date, Employment Agreement is hereby amended as follows:

1.1 The first sentence of Section 9 is hereby amended to read in its entirety as
follows:

“If, within 12 months following a Change in Control, your employment is
terminated by the Company without Cause, or by you for Good Reason; such
termination of employment constitutes a “separation from service” within the
meaning of the Treas. Reg. §1.409A-1(h)(1), without regard to any alternative
definitions thereunder; and you sign, date, return to the Company and allow to
become effective a release of all claims in a form satisfactory to the Company
in its sole discretion (the “Release”) (provided that the effective date of such
Release shall be no later than sixty (60) days following your termination of
employment); then in lieu of any Severance Benefits set forth in Section 10
herein, you shall be entitled to receive the following severance benefits (the
“Change in Control Severance Benefits”)

1.2 The last sentence of Section 9(b) is hereby amended to read in its entirety
as follows:

“The severance pay will be subject to required payroll deductions and
withholdings, and will be paid in twenty-six (26) equal installments over a
period of twelve (12) months, with such payments made on the Company’s normal
payroll schedule; provided, however, that any payments delayed pending the
effective date of the Release shall be paid in arrears on the payroll date next
following such effective date; and”

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1.3 The first sentence of Section 10 is hereby amended to read in its entirety
as follows:

“If, at any time other than during the 12 month period following a Change in
Control, your employment is terminated by the Company without Cause, or by you
for Good Reason; such termination of employment constitutes a “separation from
service” within the meaning of the Treas. Reg. §1.409A-1(h)(1), without regard
to any alternative definitions thereunder; and you sign, date, return to the
Company and allow to become effective a release of all claims in a form
satisfactory to the Company in its sole discretion (the “Release”) (provided
that the effective date of such Release shall be no later than sixty (60) days
following your termination of employment); then you shall be entitled to receive
the following severance benefits (the “Severance Benefits”):”

1.4 The second sentence of Section 10(a), is hereby amended to read in its
entirely as follows:

“The severance pay will be subject to required payroll deductions and
withholdings, and will be paid in thirteen (13) equal installments over a period
of six (6) months, with such payments made on the Company’s normal payroll
schedule; provided, however, that any payments delayed pending the effective
date of the Release shall be paid in arrears on the payroll date next following
such effective date.”

1.5 Section 12, “Deferred Compensation”, is hereby amended to read in its
entirety as follows:

“If the Company (or, if applicable, any successor entity thereto) determines
that the severance payments and benefits provided to you hereunder (any such
payments, the “Agreement Payments”) constitute “deferred compensation” under
Section 409A of the Internal Revenue Code of 1986, as amended (together, with
any state law of similar effect, “Section 409A”) and if you are a “specified
employee” of the Company (or, if applicable, any successor entity thereto), as
such term is defined in Section 409A(a)(2)(B)(i) (a “Specified Employee”), then,
solely to the extent necessary to avoid the imposition of the adverse personal
tax consequences under Section 409A, the timing of the Agreement Payments with
be delayed as follows: on the earliest to occur of (1) the date that is six
months and one day after the date of termination of your employment, and (2) the
date of your death (such earliest date, the “Delayed Initial Payment Date”), the
Company (or the successor entity thereto, as applicable) shall (i) pay to you a
lump sum amount equal to the sum of the Agreement Payments that you would
otherwise have received through the Delayed Initial Payment Date if the
commencement of the payment of the Agreement Payments had not been delayed
pursuant to this Section 12 and (ii) commence paying the balance of the
Agreement Payments in accordance with the applicable payment schedule set forth
in this Agreement. Prior to the imposition of any delay on the Agreement
Payments as set forth above, it is intended that (A) each installment of the
Agreement Payments be regarded as a separate “payment” for purposes of Treas.
Reg. §1.409A-2(b)(2)(i), (B) all Agreement Payments satisfy, to the greatest
extent possible, the exemptions from the application of Section 409A provided
under Treas. Reg. §1.409A-1(b)(4) and 1.409A-1(b)(9)(iii), and (C) the Agreement
Payments consisting of COBRA premiums also satisfy, to the greatest extent
possible, the exemption from the application of Section 409A provided under
Treas. Reg. §1.409A-1(b)(9)(v).”

1.6 Section 13(b) is hereby amended to read in its entirety as follows:

“If a reduction in the Payment is to be made, the reduction in payments and/or
benefits shall occur, in a manner necessary to provide you with the greatest
economic benefit. If more than one manner of reduction yields the greatest
economic benefit, the payments and benefits shall be reduced pro rata.”

 

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Except as amended herein, the Employment Agreement, as amended by the First and
Second Amendments, shall remain in full force and effect without modification.

IN WITNESS WHEREOF, the parties hereto have executed this Third Amendment as of
the Effective Date.

 

RACKABLE SYSTEMS, INC.     MAURICE LEIBENSTERN By:   /s/    MARK
BARRENECHEA             By:   /s/    MAURICE LEIBENSTERN         Name:    Mark
Barrenechea     Name:    Maurice Leibenstern Title:   President and CEO    
Title:   SVP and General Counsel Signature Date: December 30, 2008     Signature
Date: December 28, 2008

 

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