TABLE OF CONTENTS

TABLE OF CONTENTS

(continued)

ADAPTEC

2005 DEFERRED COMPENSATION PLAN

(Effective January 1, 2005)

Adaptec, Inc. has adopted this deferred compensation plan, effective January 1, 2005, entitled the Adaptec 2005 Deferred Compensation Plan (the “Plan”).  Adaptec also maintains another deferred compensation plan, entitled the Adaptec Deferred Compensation Plan, which was most recently amended and restated in its entirety, effective July 21, 2004, and which was frozen effective December 31, 2004.

The purpose of the Plan is to provide deferred compensation for a select group of management or highly compensated employees of Adaptec and its subsidiaries.  The Plan is intended to be a nonqualified deferred compensation plan.  Accordingly, it is intended that the Plan be exempt from the requirements of Parts 2, 3 and 4 of Title I of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”) pursuant to Sections 201(2), 301(a)3) and 401(a)(1) of ERISA. This Plan is intended to meet the applicable requirements of the American Jobs Protection Act of 2004.

ARTICLE I

DEFINITIONS

Whenever used herein, the masculine pronoun shall be deemed to include the feminine, and the singular to include the plural, unless the context clearly indicates otherwise, and the following definitions shall govern the Plan:

1.1           “ Account and Sub Account ” “Account” means the book entry account established under the Plan for each Participant to which the Participant’s Salary Deferral Amounts, AIP Deferral Amounts, VIP Deferral Amounts, MIP Deferral Amounts, any Additional Contributions made by the Employer pursuant to Article III, and the Interest with respect thereto shall be credited.  Such Account balance shall be reduced by any distributions made to the Participant or the Participant’s Beneficiary(ies) and any charges that may be imposed on such Account pursuant to the terms of the Plan.

In addition, a “Sub Account” may be established under the Plan for each Participant who is (i) actively employed by the Employer, (ii) receiving distributions pursuant to a Benefit Distribution Election, and (iii) elects to make Salary deferrals and/or deferrals of amounts payable under the AIP, VIP and/or MIP to this Plan or is receiving Additional Contributions.  Such “Sub Account” shall be a book entry account established under the Plan for each such Participant to which the Participant’s Salary Deferral Amounts, AIP Deferral Amounts, VIP Deferral Amounts, MIP Deferral Amounts, any Additional Contributions made by the Employer pursuant to Article III, and the Interest with respect thereto shall be credited.  Such Sub Account balance shall separately be reduced by any distributions made to the Participant or the

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Participant’s Beneficiary(ies) and any charges that may be imposed on such Sub Account pursuant to the terms of the Plan.

Account and Sub Account may be referred to herein collectively as “Accounts.”

1.2           “ Adaptec ” means Adaptec, Inc., a Delaware corporation and any successor organization thereto.

1.3           “ AIP ”  means the Adaptec Incentive Plan, as amended from time to time.

1.4           “ Additional Contribution ” means an Additional Contribution, contributed by the Employer on behalf of a Participant pursuant to Article III.

1.5           “ AIP Deferral Amount ” means the amount or percentage of bonus or incentive payments that an Eligible Employee is entitled to under the AIP and elects to contribute to the Plan pursuant to a valid Election form in accordance with the provisions of Article III.

1.6           “ Benchmark Fund ” means one or more of the mutual funds or contracts selected by the Deferred Compensation Committee pursuant to Section 4.3(a).

1.7           “ Beneficiary ” means one, some, or all (as the context shall require) of those persons, trusts or other entities designated by a Participant to receive the undistributed portion of his/her Accounts following the Participant’s death.

1.8           “ Benefit Distribution Election ” means the form of election, as prescribed by the Plan Administrator and as may be modified from time to time, upon which a Participant shall designate his/her Distribution Date.

1.9           “ Benefits ” means the amount(s) credited to Participant’s Accounts.

1.10         “ Board of Directors ” or “ Board ” means the Board of Directors of Adaptec.

1.11         “ Change of Control ” means (i) a “change in the ownership of a corporation” (ii) a “change in effective control of a corporation” or (iii) a “change in the ownership of a substantial portion of a corporations’ assets” as such terms are defined in guidance issued by the Secretary of the Treasury or Internal Revenue Service pursuant to Section 885(e) of the American Jobs Creation Act of 2004, including, Notice 2005-1, Section B, Q&As 11-14.

1.12         “ Code ” means the Internal Revenue Code of 1986, as amended.

1.13         “ Deferred Compensation Committee ” means the committee appointed by the Board which shall function as the Plan Administrator and which shall be composed of the individuals serving the Company in the following positions:

(a)           Chief Executive Officer of Adaptec

(b)           The senior executive of Adaptec responsible for Human Resources

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(c)           Manager, Employee Benefits

1.14         “ Distribution Date ” means the date on which distribution of a Participant’s Benefits is made or commenced pursuant to Article V.

1.15         “ Effective Date ” means January 1, 2005.

1.16         “ Election” means the form on which a Participant elects to make Salary deferrals and/or deferrals of amounts payable under the AIP, VIP and/or MIP to this Plan.  Such Election shall be in a form prescribed by the Plan Administrator as it may be modified from time to time.

1.17         “ Eligible Employee ” means an employee of the Employer who is a member of a select group of management or highly compensated employees as more particularly described in Article II and who has been designated by the Plan Administrator, in the Plan Administrator’s sole discretion, to be eligible to participate in the Plan and shall also include every non-employee member of the Board of Directors.

1.18         “ Employer ” means Adaptec or a subsidiary thereof that has adopted this Plan with the approval of Adaptec.

1.19         “ Interest ” means the investment return or loss determined in accordance with Article IV, which shall be credited to the Participant’s Accounts.

1.20         “ Interest Rate ” shall have the meaning set forth in Section 4.3(c).

1.21         “ MIP ” means the Management Incentive Plan adopted by the Company in July 2004, as it may be amended from time to time.

1.22         “ MIP Deferral Amount ” means the amount or percentage of bonus or incentive payments that an Eligible Employee is entitled to under the MIP and elects to contribute to the Plan pursuant to a valid Election form in accordance with the provisions of Article III.

1.23         “ Participant ” means an Eligible Employee who has elected to participate in the Plan by executing an Election form.  A Participant shall also mean an Eligible Employee for whom Additional Contributions are made, regardless of whether such Eligible Employee has executed an Election form.

1.24         “ Plan ” means this Adaptec 2005 Deferred Compensation Plan, as it may be amended from time to time.

1.25         “ Plan Administrator ” means the Deferred Compensation Committee selected to administer this Plan and to take such other actions as may be specified herein.

1.26         “ Plan Year ” means the calendar year.

1.27         “ Retirement with the Consent of the Employer ” means a Participant’s voluntary termination of employment or ceasing to serve as a non-employee member of the Board, if prior

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to the date employment is terminated or Board membership ceases the Participant completed at least five years of service for the Employer, including service for any subsidiary or former subsidiary either as an Employee or member of the Board.

1.28         “ Salary ”  means the base salary paid by the Employer, but shall not include any other form of compensation, whether taxable or non-taxable, including, but not limited to, bonuses, commissions, overtime, incentive payments, non-monetary awards and other forms of additional compensation.  In the case of a Participant who is a non-employee member of the Board, “salary” shall mean all cash compensation for service as a member of the Board.

1.29         “ Salary Deferral Amount ” means the Salary Deferral Amount which the Participant elects to contribute to the Plan pursuant to a valid Election form in accordance with the provisions of Article III.

1.30         “ Termination Event ” means the termination of the Participant’s employment with the Employer or ceasing to be a member of the Board for any reason, including termination or cessation in the event of Total Disability but not including the Participant’s Retirement with the Consent of the Employer.

1.31         “ Total Disability ” a Participant shall be considered disabled if the Participant is, by reason of any medically determinable physical or mental impairment which can be expected to result in death or can be expected to last for a continuous period, of not less than twelve (12) months, receiving income replacement benefits for a period of not less than three (3) months under an accident and health plan covering employees of the Participant’s Employer.

1.32         “ Trust ” means the legal entity created by the Trust Agreement.

1.33         “ Trust Agreement ” means that trust agreement entered into between Adaptec and Putnam Fiduciary Trust Company, effective April 1, 2002, as amended effective January 1, 2005, as it may subsequently be amended from time to time.

1.34         “ Trustee ” means the original Trustee(s) named in the Trust Agreement and any duly appointed successor(s) thereto.

1.35         “ VIP ” means the Variable Incentive Plan maintained by Adaptec, as it may be amended from time to time.

1.36         “ VIP Deferral Amount” means the amount or percentage of bonus or incentive payments that an Eligible Employee is entitled to under the VIP and elects to contribute to the Plan pursuant to a valid Election form in accordance with the provisions of Article III.

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ARTICLE II

ELIGIBILITY

2.1           Eligibility .  Eligibility for participation in the Plan shall be limited to non-employee members of the Board and to key management or highly compensated employees of the Employer who are selected by the Plan Administrator, in its sole discretion, to participate in the Plan.  Individuals who are in this select group shall be notified as to their eligibility to participate in the Plan.  For purposes of the Plan, the phrase “select group of management or highly compensated employees” shall include those individuals employed as directors and those individuals employed in positions at a higher level, all as determined by the Plan Administrator.

2.2           Commencement of Participation .  An Eligible Employee may begin participation in the Plan upon the Eligible Employee’s submission of a valid Election form pursuant to Article III.  In order to commence Salary deferrals and/or deferrals of amounts payable under the AIP, VIP and/or MIP, the Election form must be returned to the Plan Administrator within thirty (30) days of the date an individual first becomes an Eligible Employee; otherwise the Election form must be returned to the Plan Administrator in advance of the next subsequent Plan Year, in accordance with rules and procedures established by the Plan Administrator.

2.3           Cessation of Participation .  Active participation in the Plan shall end when a Participant’s employment terminates for any reason.  No contributions to the Plan shall be made with respect to compensation paid after such termination date.  Upon termination of employment, a Participant shall remain an inactive participant in the Plan until all of the Benefits to which he or she is entitled under this Plan have been paid in full.

2.4           Suspension of Participation .  A Participant who is employed by a subsidiary which has not adopted the Plan shall be a suspended Participant.  No contributions to the Plan shall be made on behalf of a suspended Participant.  Except as otherwise provided in this Article II, a suspended Participant shall continue to participate in the Plan in accordance with its terms.

ARTICLE III

DEFERRALS AND CONTRIBUTIONS

3.1           Deferral Elections Generally .  Each Participant must complete a deferral Election in the form and manner specified by the Committee for each Plan Year with respect to which he or she wishes to defer all or part of his or her Salary or payment under the AIP, VIP and/o