EX-99.1

VOTING AGREEMENT, dated as of August 11, 2016 (this “Agreement”), among Hewlett Packard Enterprise Company, a Delaware corporation (“Parent”), and the stockholders of Silicon Graphics International Corp., a Delaware corporation (the “Company”), listed on Schedule A hereto (each, a “Stockholder” and, collectively, the “Stockholders”).

WHEREAS, concurrently herewith, Parent, Satellite Acquisition Sub, Inc., a Delaware corporation and wholly-owned subsidiary of Parent (“Acquisition Sub”) and the Company are entering into an Agreement and Plan of Merger (the “Merger Agreement”; capitalized terms used but not defined in this Agreement shall have the meanings ascribed to them in the Merger Agreement), pursuant to which (and subject to the terms and conditions set forth therein) Acquisition Sub will be merged with and into the Company, with the Company continuing as the surviving corporation in the merger (the “Merger”);

WHEREAS, each Stockholder is the record and beneficial owner (within the meaning of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, which meaning will apply for all purposes of this Agreement whenever the term “beneficial owner” or “beneficially own” is used) of shares of common stock, par value $0.001 per share, of the Company (“Shares”) as set forth on Schedule A hereto (with respect to each Stockholder, the “Owned Shares”; the Owned Shares and any additional Shares or other voting securities of the Company of which such Stockholder acquires record or beneficial ownership after the date hereof, including, without limitation, by purchase, as a result of a stock dividend, stock split, recapitalization, combination, reclassification, exchange or change of such shares, or upon exercise or conversion of any securities, such Stockholder’s “Covered Shares”);

WHEREAS, as a condition and inducement to Parent and Acquisition Sub’s willingness to enter into the Merger Agreement and to proceed with the transactions contemplated thereby, including the Merger, Parent and the Stockholders are entering into this Agreement; and

WHEREAS, the Stockholders acknowledge that Parent and Acquisition Sub are entering into the Merger Agreement in reliance on the representations, warranties, covenants and other agreements of the Stockholders set forth in this Agreement and would not enter into the Merger Agreement if any Stockholder did not enter into this Agreement.

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants and agreements herein contained, and intending to be legally bound hereby, Parent and the Stockholders hereby agree as follows:

1. Agreement to Vote. Prior to the Termination Date (as defined herein), each Stockholder irrevocably and unconditionally agrees that it shall at any meeting of the stockholders of the Company (whether annual or special and whether or not an adjourned or postponed meeting), however called, or in connection with any written consent of stockholders of the Company (a) when a meeting is held, appear at such meeting or otherwise cause the

Covered Shares to be counted as present thereat for the purpose of establishing a quorum, and respond to each request by the Company for written consent, if any and (b) vote (or consent), or cause to be voted at such meeting (or validly execute and return and cause such consent to be granted with respect to), all Covered Shares (i) in favor of the Merger, the adoption of the Merger Agreement and any other matters necessary for consummation of the Merger and the other transactions contemplated in the Merger Agreement and (ii) against (A) any Acquisition Proposal, (B) any proposal for any recapitalization, reorganization, liquidation, dissolution, amalgamation, merger, sale of assets or other business combination between the Company and any other Person (other than the Merger), and (C) any other action that could reasonably be expected to impede, interfere with, delay, postpone or adversely affect the Merger or any of the transactions contemplated by the Merger Agreement or this Agreement (collectively, the “Covered Proposals”). Notwithstanding the foregoing, nothing in this Agreement shall require any Stockholder to vote or otherwise consent to any amendment to the Merger Agreement or the taking of any action that could result in the amendment, modification or a waiver of a provision therein, in any such case, in a manner that decreases the amount or changes the form of the Merger Consideration. Except as expressly set forth in this Section 1 with respect to Covered Proposals, Stockholders shall not be restricted from voting in favor of, against or abstaining with respect to any other matter presented to the stockholders of the Company.

(a) EACH STOCKHOLDER HEREBY GRANTS TO, AND APPOINTS, PARENT, THE EXECUTIVE OFFICERS OF PARENT, AND ANY OTHER DESIGNEE OF PARENT, EACH OF THEM INDIVIDUALLY, SUCH STOCKHOLDER’S IRREVOCABLE (UNTIL THE TERMINATION DATE) PROXY AND ATTORNEY-IN-FACT (WITH FULL POWER OF SUBSTITUTION) TO VOTE THE COVERED SHARES AS INDICATED IN SECTION 1 WITH RESPECT TO COVERED PROPOSALS. EACH STOCKHOLDER INTENDS THIS PROXY TO BE IRREVOCABLE (UNTIL THE TERMINATION DATE) AND COUPLED WITH AN INTEREST AND WILL TAKE SUCH FURTHER ACTION OR EXECUTE SUCH OTHER INSTRUMENTS AS MAY BE NECESSARY TO EFFECTUATE THE INTENT OF THIS PROXY AND HEREBY REVOKES ANY PROXY PREVIOUSLY GRANTED BY SUCH STOCKHOLDER WITH RESPECT TO THE COVERED SHARES (THE STOCKHOLDER REPRESENTING TO THE COMPANY THAT ANY SUCH PROXY IS NOT IRREVOCABLE).

(b) The proxy granted in this Section 2 shall automatically expire upon the termination of this Agreement.

3. No Inconsistent Agreements. Each Stockholder hereby represents, covenants and agrees that, except as contemplated by this Agreement, such Stockholder (a) has not entered into, and shall not enter into at any time prior to the Termination Date, any voting agreement or voting trust with respect to any Covered Shares and (b) has not granted, and shall not grant at any time prior to the Termination Date, a proxy or power of attorney with respect to any Covered Shares, in either case, which is inconsistent with such Stockholder’s obligations pursuant to this Agreement.

4. Termination. This Agreement shall terminate upon the earliest of (a) the Effective Time, (b) the termination of the Merger Agreement in accordance with its terms and (c) written notice of termination of this Agreement by Parent to the Stockholders (such earliest date being referred to herein as the “Termination Date”); provided, that the provisions set forth in Sections 8 and 12 to 26 shall survive the termination of this Agreement; provided further, that any liability incurred by any party hereto as a result of a breach of a term or condition of this Agreement prior to such termination shall survive the termination of this Agreement.

5. Representations and Warranties of Stockholders. Each Stockholder, as to itself (severally and not jointly), hereby represents and warrants to Parent as follows:

(a) Such Stockholder is the record and beneficial owner of, and has good and valid title to, the Covered Shares, free and clear of Encumbrances other than as created by this Agreement. Such Stockholder has sole voting power, sole power of disposition, sole power to demand appraisal rights and sole power to agree to all of the matters set forth in this Agreement, in each case with respect to all of such Covered Shares, with no limitations, qualifications or restrictions on such rights, subject to applicable federal securities laws and the terms of this Agreement. As of the date hereof, other than the Owned Shares (and the equity awards relating thereto), such Stockholder does not own beneficially or of record any (i) shares of capital stock or voting securities of the Company, (ii) securities of the Company convertible into or exchangeable for shares of capital stock or voting securities of the Company or (iii) options or other rights to acquire from the Company any capital stock, voting securities or securities convertible into or exchangeable for capital stock or voting securities of the Company.

(b) Each such Stockholder which is an entity is duly organized, validly existing and in good standing under the laws of the jurisdiction of its formation and has all requisite power and authority to execute and deliver this Agreement and to perform its obligations hereunder; each such Stockholder who is a natural person has full legal power and capacity to execute and deliver this Agreement and to perform such Stockholder’s obligations hereunder. The execution, delivery and performance of this Agreement by each such Stockholder which is an entity, the performance by such Stockholder of its obligations hereunder and the consummation by such Stockholder of the transactions contemplated hereby have been duly and validly authorized by such Stockholder and no other actions or proceedings on the part of such Stockholder are necessary to authorize the execution and delivery by such Stockholder of this Agreement, the performance by such Stockholder of its obligations hereunder or the consummation by such Stockholder of the transactions contemplated hereby. This Agreement has been duly and validly executed and delivered by such Stockholder and, assuming due authorization, execution and delivery by Parent, constitutes a legal, valid and binding obligation of such Stockholder, enforceable against such Stockholder in accordance with its terms, except as enforcement may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally and by general principles of equity (regardless of whether considered in a proceeding in equity or at law). If such Stockholder is married, and any of the Covered Shares of such Stockholder constitute community property or otherwise need spousal or other approval for this Agreement to be legal, valid and binding, this Agreement has been duly and validly executed and delivered by such Stockholder’s spouse and, assuming due authorization, execution and delivery by Parent, constitutes a legal, valid and binding obligation of such Stockholder’s spouse, enforceable

against such Stockholder’s spouse in accordance with its terms, except as enforcement may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally and by general principles of equity (regardless of whether considered in a proceeding in equity or at law).

(c) Except for the applicable requirements of the Exchange Act, (i) no filing with, and no permit, authorization, consent or approval of, any Governmental Body is necessary on the part of such Stockholder for the execution, delivery and performance of this Agreement by such Stockholder or the consummation by such Stockholder of the transactions contemplated hereby and (ii) neither the execution, delivery or performance of this Agreement by such Stockholder nor the consummation by such Stockholder of the transactions contemplated hereby nor compliance by such Stockholder with any of the provisions hereof shall (A) conflict with or violate, any provision of the organizational documents of any such Stockholder which is an entity, (B) result in any breach or violation of, or constitute a default (or an event which, with notice or lapse of time or both, would become a default) under, or give to others any rights of termination, amendment, acceleration or cancellation of, or result in the creation of an Encumbrance on such property or asset of such Stockholder pursuant to, any Contract to which such Stockholder is a party or by which such Stockholder or any property or asset of such Stockholder is bound or affected or (C) violate any order, writ, injunction, decree, statute, rule or regulation applicable to such Stockholder or any of such Stockholder’s properties or assets, in each case other than as would not restrict, prohibit or impair the exercise by Parent of its rights under this Agreement or the performance by any party of its obligations under this Agreement.

(d) There is no action, suit, investigation, complaint or other proceeding pending against any such Stockholder or, to the knowledge of such Stockholder, any other Person or, to the knowledge of such Stockholder, threatened against any Stockholder or any other Person that restricts or prohibits (or, if successful, would restrict or prohibit) the exercise by Parent of its rights under this Agreement or the performance by any party of its obligations under this Agreement.

(e) Except as provided in the Merger Agreement, no broker, finder or investment banker is entitled to any brokerage, finder’s or other fee or commission in connection with the transactions contemplated by the Merger Agreement or this Agreement based upon arrangements made by or on behalf of the Stockholder (in such Stockholder’s capacity as a stockholder of the Company and in no other capacity).

(f) Such Stockholder understands and acknowledges that Parent and Acquisition Sub are entering into the Merger Agreement in reliance upon such Stockholder’s execution and delivery of this Agreement and the representations and warranties of such Stockholder contained herein.

6. Certain Covenants of Stockholder. Each Stockholder, for itself (severally and not jointly), hereby covenants and agrees as follows:

(a) Prior to the Termination Date, such Stockholder (solely in his, her or its capacity as a stockholder and in no other capacity) shall not, and shall not authorize or permit any of its Subsidiaries or Representatives, directly or indirectly, to:

(i) solicit, initiate, endorse, knowingly encourage or knowingly facilitate the making by any Person (other than the other parties to the Merger Agreement) of any Acquisition Proposal;

(ii) enter into, continue or otherwise participate in any discussions or negotiations regarding, or furnish to any Person any information or data with respect to, any Acquisition Proposal;

(iii) execute or enter into any Contract constituting or relating to any Acquisition Proposal, or approve or recommend or propose to approve or recommend any Acquisition Proposal or any Contract constituting or relating to any Acquisition Proposal (or authorize or resolve to agree to do any of the foregoing actions); or

(iv) make, or in any manner participate in a “solicitation” (as such term is used in the rules of the Securities and Exchange Commission (the “SEC”)) of proxies or powers of attorney or similar rights to vote, or seek to advise or influence any Person with respect to the voting of the Shares intending to facilitate any Acquisition Proposal or cause stockholders of the Company not to vote to approve the Merger or any other transaction contemplated by the Merger Agreement.

(b) Such Stockholder will immediately cease and cause to be terminated all existing discussions or negotiations with any Person conducted heretofore with respect to any of the matters described in Section 6(a) above, to the extent such discussions or negotiations occurred in the capacity of the Stockholder as a stockholder and in no other capacity.

(c) Prior to the Termination Date, and except as contemplated hereby, such Stockholder shall not (i) tender into any tender or exchange offer, (ii) sell (constructively or otherwise), transfer, pledge, hypothecate, grant, encumber, assign or otherwise dispose of (collectively “Transfer”), or enter into any contract, option, agreement or other arrangement or understanding with respect to the Transfer of any of the Covered Shares or beneficial ownership or voting power thereof or therein (including by operation of law), (iii) grant any proxies or powers of attorney, deposit any Covered Shares into a voting trust or enter into a voting agreement with respect to any Covered Shares or (iv) knowingly take any action that would make any representation or warranty of such Stockholder contained herein untrue or incorrect or have the effect of preventing or disabling such Stockholder from performing its obligations under this Agreement, in each case other than Permitted Transfers. Any Transfer in violation of this provision shall be void. Such Stockholder further agrees to authorize and request the Company to notify the Company’s transfer agent that there is a stop transfer order with respect to all of the Covered Shares and that this Agreement places limits on the voting of the Covered Shares, other than Permitted Transfers. If so requested by Parent, such Stockholder agrees that the certificates representing Covered Shares shall bear a legend stating that they are subject to this Agreement and to the irrevocable proxy granted in Section 2(a).

(d) Prior to the Termination Date, in the event that a Stockholder acquires record or beneficial ownership of, or the power to vote or direct the voting of, any additional Shares or other voting interests with respect to the Company, such Shares or voting interests shall, without further action of the parties, be deemed Covered Shares and subject to the

provisions of this Agreement, and the number of Shares held by such Stockholder set forth on Schedule A hereto will be deemed amended accordingly and such Shares or voting interests shall automatically become subject to the terms of this Agreement. Each Stockholder shall promptly notify Parent and the Company of any such event.

(e) “Permitted Transfers” shall mean any Transfer of securities (including any contract, option, agreement or other arrangement or understanding with respect thereto) (i) for the net settlement of Stockholder’s Company Options (to pay the exercise price thereof and any tax withholding obligations), (ii) for the net settlement of Stockholder’s Company RSUs settled in Shares (to pay any tax withholding obligations), (iii) for the exercise of Stockholder’s Company Options, to the extent such options would expire prior to the Effective Time, (iv) for the exercise of Stockholder’s Company Options, or the receipt upon settlement of Stockholder’s Company RSUs, and the sale of a sufficient number of such Shares acquired upon exercise or settlement of such securities as would generate sales proceeds sufficient to pay the aggregate applicable exercise price of shares then exercised under such options and the taxes payable by Stockholder as a result of such exercise or settlement, (v) made as a bona fide gift to a charitable entity, (vi) to any family member or trust for the benefit of any family member, (vii) to any stockholder, member or partner of any Stockholder which is an entity, (viii) to any Affiliate of Stockholder, or (ix) to any person or entity if and to the extent required by any non-consensual legal order, by divorce decree or by will, intestacy or other similar Legal Requirement, so long as, in the case of the foregoing clauses (vi), (vii), (viii) and (ix), the assignee or transferee agrees to be bound by the terms of this Agreement and executes and delivers to the parties hereto a written consent and joinder memorializing such agreement.

7. Stockholder Capacity. This Agreement is being entered into by each Stockholder solely in its capacity as a stockholder of the Company, and nothing in this Agreement shall restrict or limit the ability of any Stockholder who is a director or officer of the Company to take any action in his or her capacity as a director or officer of the Company. Any references to Subsidiaries, Affiliates or Representatives of Stockholder in this Agreement shall not be deemed to include the Company, its Subsidiaries or Affiliates, or their respective Representatives.

8. Waiver of Appraisal Rights. Each Stockholder hereby waives any rights of appraisal or rights to dissent from the Merger that such Stockholder may have under applicable Legal Requirements.

9. Disclosure. Each Stockholder hereby authorizes Parent and the Company to publish and disclose in any announcement or disclosure required by the SEC and in the Proxy Statement such Stockholder’s identity and ownership of the Covered Shares and the nature of such Stockholder’s obligations under this Agreement.

10. Further Assurances. From time to time, at the request of Parent and without further consideration, each Stockholder shall take such further action as may reasonably be deemed by Parent to be necessary or desirable to consummate and make effective the transactions contemplated by this Agreement.

11.Non-Survival of Representations and Warranties. The representations and warranties of the Stockholders contained herein shall not survive the Termination Date.

12. Amendment and Modification. This Agreement may not be amended, modified or supplemented in any manner, whether by course of conduct or otherwise, except by an instrument in writing specifically designated as an amendment hereto, signed on behalf of each party and otherwise as expressly set forth herein.

13. Waiver. No failure on the part of any party to exercise any power, right, privilege or remedy under this Agreement, and no delay on the part of any party in exercising any power, right, privilege or remedy under this Agreement, shall operate as a waiver of such power, right, privilege or remedy; and no single or partial exercise of any such power, right, privilege or remedy shall preclude any other or further exercise thereof or of any other power, right, privilege or remedy. No party shall be deemed to have waived any claim arising out of this Agreement, or any power, right, privilege or remedy under this Agreement, unless the waiver of such claim, power, right, privilege or remedy is expressly set forth in a written instrument duly executed and delivered on behalf of such party; and any such waiver shall not be applicable or have any effect except in the specific instance in which it is given.

14. Notices. Any notice or other communication required or permitted to be delivered to any party under this Agreement shall be in writing and shall be deemed properly delivered, given and received: (a) if delivered by hand, when delivered; (b) if sent via facsimile with confirmation of receipt, when transmitted and receipt is confirmed; (c) if sent by electronic mail, upon delivery; (d) if sent by registered, certified or first class mail, the third Business Day after being sent; and (e) if sent by overnight delivery via a national courier service, one Business Day after being sent, in each case to the address or facsimile telephone number set forth beneath the name of such party below (or to such other address or facsimile telephone number as such party shall have specified in a written notice given to the other parties hereto):

(i) If to a Stockholder, to the address set forth opposite such Stockholder’s name on Schedule A hereto.

15. Entire Agreement. This Agreement (including all Exhibits and Schedules hereto) and the other agreements referred to in this Agreement constitute the entire agreement and supersede all prior agreements and understandings, both written and oral, among or between any of the parties with respect to the subject matter hereof and thereof. This Agreement may be executed in several counterparts, each of which shall be deemed an original and all of which shall constitute one and the same instrument.

16. No Third-Party Beneficiaries. Nothing in this Agreement, express or implied, is intended to or shall confer upon any Person other than the parties and their respective successors and permitted assigns any legal or equitable right, benefit or remedy of any nature under or by reason of this Agreement.

(a) This Agreement shall be governed by, and construed and enforced in accordance with, the laws of the State of Delaware, regardless of the laws that might otherwise govern under applicable principles of conflicts of laws thereof.

(b) In any action between any of the parties arising out of or relating to this Agreement or the transactions contemplated hereby each of the parties: (i) irrevocably and unconditionally consents and submits to the exclusive jurisdiction and venue of the Court of Chancery of the State of Delaware in and for New Castle County, Delaware (unless the federal courts have exclusive jurisdiction over the matter, in which case the United States District Court for the District of Delaware); (ii) agrees that it will not attempt to deny or defeat such jurisdiction by motion or other request for leave from such court; and (iii) agrees that it will not bring any such action in any court other than the Court of Chancery of the State of Delaware in and for New Castle County, Delaware (unless the federal courts have exclusive jurisdiction over the matter, in which case the United States District Court for the District of Delaware). Service of any process, summons, notice or document to any party’s address and in the manner set forth in Section 17 shall be effective service of process for any such action.

(c) EACH PARTY ACKNOWLEDGES THAT ANY CONTROVERSY WHICH MAY ARISE UNDER THIS AGREEMENT IS LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES, AND THEREFORE IT HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY ACTION ARISING OUT OF OR RELATING TO THIS AGREEMENT OR ANY OF THE TRANSACTIONS CONTEMPLATED HEREBY. EACH PARTY ACKNOWLEDGES, AGREES AND CERTIFIES THAT: (i) NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD, IN THE EVENT OF LITIGATION, SEEK TO PREVENT OR DELAY ENFORCEMENT OF EITHER OF SUCH WAIVERS; (ii) IT UNDERSTANDS AND HAS CONSIDERED THE IMPLICATIONS OF SUCH WAIVERS; (iii) IT MAKES SUCH WAIVERS VOLUNTARILY; AND (iv) IT HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION 17(C).

18. Assignment; Successors. Neither this Agreement nor any of the rights, interests or obligations under this Agreement may be assigned or delegated, in whole or in part, by operation of law or otherwise, by either party without the prior written consent of the other party, and any such assignment without such prior written consent shall be null and void; provided, however, that Parent may assign all or any of its rights and obligations hereunder to any direct or indirect Subsidiary of Parent; provided further, that no assignment shall limit the assignor’s obligations hereunder. Subject to the preceding sentence, this Agreement will be binding upon, inure to the benefit of, and be enforceable by, the parties and their respective successors and assigns.

19. Enforcement. The parties acknowledge and agree that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with their specific terms or were otherwise breached, and that monetary damages, even if available, would not be an adequate remedy therefor. Accordingly, in the event of any breach or threatened breach of any covenant or obligation contained in this Agreement, the non-breaching party shall be entitled to obtain, without proof of actual damages (and the parties hereby waive any requirement for the securing or posting of any bond in connection with such remedy): (a) a decree or order of specific performance to enforce the observance and performance of such covenant or obligation; and (b) an injunction restraining such breach or threatened breach; this being in addition to any other remedy to which the non-breaching party is entitled at law or in equity.

20. Severability. Any term or provision of this Agreement that is invalid or unenforceable in any situation in any jurisdiction shall not affect the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the offending term or provision in any other situation or in any other jurisdiction. If a final judgment of a court of competent jurisdiction declares that any term or provision of this Agreement is invalid or unenforceable, the parties hereto agree to negotiate in an effort to replace such invalid or unenforceable term or provision with a valid enforceable term or provision that will achieve, to the extent possible, the economic, business and other purposes of such invalid or unenforceable term or provision.

21. Counterparts. This Agreement may be executed in two or more counterparts, all of which shall be considered one and the same instrument and shall become effective when one or more counterparts have been signed by each of the parties and delivered to the other party; provided, however, that if any of the Stockholders fail for any reason to execute this Agreement, then this Agreement shall become effective as to the other Stockholders who execute this Agreement.

22. Facsimile or .pdf Signature. This Agreement may be executed by facsimile or .pdf signature and a facsimile or .pdf signature shall constitute an original for all purposes.

23. Confidentiality. The Stockholders agree (a) to hold any non-public information regarding this Agreement and the Merger in strict confidence and (b) except as required by law or legal process not to divulge any such non-public information to any third Person.

24. No Presumption Against Drafting Party. Each of the parties to this Agreement acknowledges that it has been represented by counsel in connection with this Agreement and the transactions contemplated by this Agreement. Accordingly, any rule of law or any legal decision that would require interpretation of any claimed ambiguities in this Agreement against the drafting party has no application and is expressly waived.