SC TO-I/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT NO. 5

TO

SCHEDULE TO

(RULE 14d-100)

Tender Offer Statement Pursuant to Section 14(d)(1) or 13(e)(1) of

The Securities Exchange Act of 1934

Silicon Graphics, Inc.

(Name of Subject Company)

Silicon Graphics, Inc.

(Name of Filing Person)

5.25% Senior Convertible Notes Due 2004

(Title of Class of Securities)

827056AC6

(Cusip Number of Class of Securities)

Sandra M. Escher

Senior Vice President and General Counsel

Silicon Graphics, Inc.

1600 Amphitheatre Parkway

Mountain View, California 94043

(650) 960-1980

 (Name, Address and Telephone Number of Person Authorized to Receive Notices

and Communications on Behalf of Filing Persons)

Copies to:

Daniel G. Kelly, Jr.

Davis Polk & Wardwell

1600 El Camino Real

Menlo Park, California  94043

Tel: (650) 752-2000

Fax: (650) 752-2111

CALCULATION OF FILING FEE

Title Of Each Class Of Securities To Be Registered (1)	Amount To Be Registered (2)	Proposed Maximum Offering Price Per Unit	Proposed Maximum Aggregate Offering Price (3)	Amount of Registration Fee (3)
Senior Notes Due 2009	$230,000,000	100%	$175,950,000	$14,235
Senior Convertible Notes Due 2009	(4)	(4)	(4)	(4)

(1)This Schedule TO relates to the exchange by Silicon Graphics, Inc. of an aggregate of up to $230,000,000 principal amount of its 5.25% Senior Convertible Notes Due 2004 for either (a) $1,000 in principal amount of its new Senior Notes Due 2009 for each $1,000 in principal amount of notes tendered or (b) $1,000 principal amount of its new Senior Convertible Notes Due 2009 for each $1,000 in principal amount of notes tendered.

(2)This amount is the maximum principal amount of 5.25% Senior Convertible Notes due 2004 that may be received by the registrant from tendering holders.

(3)The registration fee of $14,235 has been paid in connection with the Company’s Registration Statement on Form S-4, filed April 21, 2003. The amount of the registration fee was calculated, pursuant to Rule 457(f)(1) under the Securities Act of 1933, as amended, based on $175,950,000, the market value as of April 16, 2003 of the maximum principal amount of 5.25% Senior Convertible Notes Due 2004 that may be received by the registrant from tendering holders.

(4)The total of Senior Notes Due 2009 and Senior Convertible Notes Due 2009 to be issued upon completion of this exchange offer will be no more than $230,000,000. Therefore no additional registration fee is required pursuant to Rule 457 of the Securities Act of 1933, as amended.

ýCheck box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid.  Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:	$14,235	Filing Party:	Silicon Graphics, Inc.
Form or Registration No.:	S-4 (File No. 333-104651)	Date Filed:	April 21, 2003

oCheck the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

        Check the appropriate boxes below to designate any transactions to which the statement relates:

othird-party tender offer subject to Rule 14d-1.

ýissuer tender offer subject to Rule 13e-4.

ogoing-private transaction subject to Rule 13e-3.

oamendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer.    o

Introduction

This Amendment No. 5 to Tender Offer Statement on Schedule TO amends and supplements the Tender Offer Statement on Schedule TO filed on April 21, 2003, and amended on May 6, May 22, June 30 and July 14, 2003 (as so amended, the "Schedule TO") by Silicon Graphics, Inc. (the "Company"), in connection with its offer to exchange an aggregate of up to $230,000,000 principal amount of its 5.25% Senior Convertible Notes Due 2004 (the “Old Notes”) for either (a) $1,000 in principal amount of its new Senior Notes Due 2009 (the “New Notes”) for each $1,000 in principal amount of Old Notes tendered, or (b) $1,000 principal amount of its new Senior Convertible Notes Due 2009 (the “New Convertible Notes”) for each $1,000 in principal amount of Old Notes tendered.

This exchange offer is subject to the terms and conditions set forth in the prospectus, prospectus supplements dated May 22 and June 30, 2003 and letter of transmittal filed as a part of the Company’s Registration Statement on Form S-4 (File No. 333-104651) with the Securities and Exchange Commission on April 21, 2003 and amended on May 6, May 9, May 22, June 30, July 3, July 14 and July 16, 2003 (as amended, the "Registration Statement").

The Schedule TO is hereby amended and supplemented as follows:

Item 10.  Financial Statements.

(a)(1) The information on pages 28 through 59 in SGI's Annual Report on Form 10-K for the fiscal year ended June 28, 2002 is incorporated herein by reference.

(a)(2) The information on pages 3 through 13 of SGI's Quarterly Report on Form 10-Q for the quarter ended December 27, 2002 and pages 3 through 15 of the SGI's Quarterly Report on Form 10-Q for the quarter ended March 28, 2003 is incorporated herein by reference.

(a)(3) The information in the Registration Statement under the headings "Summary—Selected Historical Financial Data of SGI", "Summary—Ratio of Earnings to Fixed Charges" and "Summary—Book Value Per Share" is incorporated herein by reference.

(b) The information in the prospectus dated July 14, 2003 included in Amendment No. 6 to the Registration Statement under the headings "Recent Developments" and "Reconciliation of Non-GAAP Financial Measures" and the information in the prospectus supplement dated July 16, 2003 under the heading "Unaudited Pro Forma Information" are incorporated herein by reference.

Item 12.  Exhibits.

(a)(1)(A)(i)Prospectus dated April 21, 2003 incorporated herein by reference to the Registration Statement.*

(a)(1)(A)(ii)Prospectus Supplement dated May 22, 2003.*

(a)(1)(A)(iii)Prospectus Supplement dated June 30, 2003.*

(a)(1)(A)(iv)Prospectus dated July 14, 2003 incorporated by reference to Amendment No. 6 to the Registration Statement.*

(a)(1)(A)(v)Prospectus Supplement dated July 16, 2003.

(a)(1)(B)Form of Letter of Transmittal, incorporated by reference to Exhibit 99.1 to the Registration Statement as amended on July 16, 2003.*

(a)(1)(C)Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees.

(a)(1)(D)Form of Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees.

(a)(1)(E)Form of Notice of Guaranteed Delivery, incorporated by reference to Exhibit 99.4 to the Registration Statement.*

(a)(1)(F)Form of Instructions to Book-Entry Transfer Participant from Owner, incorporated by reference to Exhibit 99.5 to the Registration Statement.*

(a)(5)(i)Press Release issued by Silicon Graphics, Inc. on April 21, 2003, filed pursuant to Rule 425 and incorporated by reference herein.*

(a)(5)(ii)Telephone Discussion of Exchange Offer on April 21, 2003, filed pursuant to Rule 425 and incorporated by reference herein.*

(a)(5)(iii)Press Release issued by Silicon Graphics, Inc. on May 19, 2003, filed pursuant to Rule 425 and incorporated by reference herein.*

(a)(5)(iv)Press Release issued by Silicon Graphics, Inc. on June 30, 2003, filed pursuant to Rule 425 and incorporated by reference herein.*

(a)(5)(v)Press Release issued by Silicon Graphics, Inc. on July 15, 2003, filed pursuant to Rule 425 and incorporated by reference herein.*

(b)None.

(c)None.

(d)Agreement to Tender dated April 18, 2003 between Silicon Graphics, Inc. and Highfields Capital Management LP, incorporated herein by reference to Exhibit 10.1 to the Registration Statement.*

(e)Form of Letter Agreement to Participate in Exchange Offer, incorporated herein by reference to Exhibit 10.2 of the Registration Statement, as amended on June 30, 2003.*

(g)None.

(h)None.

*      Previously filed.

SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

SILICON GRAPHICS, INC.
	/s/ Sandra M. Escher
	(Signature)
Name:	Sandra M. Escher
Title:	Senior Vice President and General Counsel
Date:	July 16, 2003

EX-99.(A)(1)(A)(V)

QuickLinks -- Click here to rapidly navigate through this document

The information in this prospectus supplement may change. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus supplement is not an offer to sell these securities and we are not soliciting offers to buy these securities in any state where the offer or sale is not permitted.

Prospectus Supplement to
Prospectus dated April 21, 2003
and Prospectus Supplement
dated May 22, 2003,
Prospectus Supplement
dated June 30, 2003,
Prospectus Supplement
dated May 22, 2003
and Prospectus Supplement
dated June 30, 2003

SILICON GRAPHICS, INC.

SUPPLEMENT TO ITS OFFER TO EXCHANGE

11.75% SENIOR NOTES DUE 2009 OR
6.50% SENIOR CONVERTIBLE NOTES DUE 2009

FOR

ALL OUR OUTSTANDING 5.25%
SENIOR CONVERTIBLE NOTES DUE 2004

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT
MIDNIGHT, NEW YORK CITY TIME, ON AUGUST 1, 2003.

        This prospectus supplement relates to our offer to exchange $1,000 principal amount of our 11.75% Senior Notes Due 2009, referred to as the New Notes, or $1,000 principal amount of our 6.50% Senior Convertible Notes Due 2009, referred to as the New Convertible Notes, for an equal amount of our 5.25% Senior Convertible Notes Due 2004, referred as the Old Notes, upon the terms and conditions specified in the prospectus dated April 21, 2003 previously filed with the Securities and Exchange Commission, which we refer to as the original prospectus. We amended our offer to provide for the payment of a fee to soliciting dealers as described in our prospectus supplement dated May 22, 2003, and further amended the terms of the offer to reduce the conversion price of the New Convertible Notes and provide that we would meet certain financial performance and debt reduction conditions as described more fully in the prospectus supplement dated June 30, 2003. We refer to the prospectus supplements dated May 22, 2003 and June 30, 2003 as the prior prospectus supplements. We are now amending the terms of the offer to decrease from 90% to 85% of the minimum principal amount of Old Notes that must be tendered for exchange as a condition to our completing the exchange offer. The offer will remain open until midnight on Friday August 1, 2003.

At the close of business on July 14, 2003, holders had tendered $ 163.7 million aggregate principal amount of Old Notes in the Exchange Offer, which represents approximately 71% of the outstanding Old Notes. If sufficient Old Notes are not tendered by the expiration date, the Company intends to terminate the exchange offer and not accept any Old Notes. See Risk Factors – "If the Exchange Offer is unsuccessful we may be unable to repay the Old Notes at maturity" and "Failure to complete the exchange offer would have a material adverse effect on our business" in the original prospectus.

Except for the change in minimum condition described herein and the change in the expiration date, all other terms of the exchange offer remain the same.

        This prospectus supplement amends, modifies and supercedes certain information included in the original prospectus and prior prospectus supplements to reflect the change in minimum condition and the change to the expiration date. This prospectus supplement should be read in conjunction with the original prospectus and prior prospectus supplements.

Noteholders who have already tendered their Old Notes pursuant to the exchange offer and who have not withdrawn such Old Notes do not need to take any further action to receive the New Notes or the New Convertible Notes, which will benefit from the changes in terms described herein. Noteholders who wish to tender but have not yet done so should follow the instructions included in the letter of transmittal previously provided.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved these securities or determined if this prospectus supplement is accurate or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is July 16, 2003.

THE EXCHANGE OFFER

Amended Terms of the Exchange Offer

        The discussion set forth in the original prospectus and prior prospectus supplements regarding the terms of the exchange offer is hereby modified, amended and supplemented as follows:

Conditions to the Exchange Offer

        The exchange offer is subject to various conditions, including that at least 85% of the outstanding principal amount of Old Notes be validly tendered and not withdrawn by the expiration date and that the registration statement and any post-effective amendment to the registration statement covering the 2009 Notes be effective under the Securities Act of 1933, as amended.

Expiration of the Exchange Offer

        The term "expiration date" means midnight, New York City time, on August 1, 2003

IMPACT ON UNAUDITED PRO FORMA INFORMATION

        The decrease in the minimum amount of Old Notes that must be tendered as a condition to the exchange offer from 90% to 85% of the outstanding principal amount has the following effects on the information presented under the captions "Pro Forma Ratio of Earnings to Fixed Changes" and "Interest Expense" presented in the original prospectus:

UNAUDITED PRO FORMA INFORMATION

        The unaudited information below is presented pro forma to reflect the effects of the exchange offer under two alternative scenarios, assuming in each case that 85% of holders of the Old Notes participate in the exchange offer. Under alternative (1) below, we have assumed that the holders of Old Notes exchange for $196 million in principal amount of New Notes, and under alternative (2) that holders exchange for $118 million in principal amount of New Notes and $78 million in principal amount of New Convertible Notes.

Pro Forma Ratio of Earnings to Fixed Charges

        For the fiscal year ended June 28, 2002 and for the nine months ended March 28, 2003, earnings would have been insufficient to cover fixed charges by:

        Under alternative (1) $95.0 million and $116.9 million, respectively, and

        Under alternative (2) $90.9 million and $113.8 million, respectively.

Pro Forma Interest Expense

        For the fiscal year ended June 28, 2002 and for the nine months ended March 28, 2003, the Company's interest expense would have been:

        Under alternative (1) $24.8 million and $18.6 million, respectively, and

        Under alternative (2) $20.7 million and $15.5 million, respectively.

        Actual interest expense for the corresponding periods was $12.1 million and $6.1 million, respectively.

2

PROCEDURE FOR TENDERING NOTES

        Noteholders who have already tendered their Old Notes pursuant to the exchange offer and who have not withdrawn such Old Notes do not need to take any further action to receive the New Notes or New Convertible Notes.

        Noteholders who wish to tender but have not yet done so should follow the instructions included in the letter of transmittal previously provided. As a result of the extension of the offer, tendering noteholders are entitled to withdraw tendered Old Notes until midnight, New York City time, on August 1, 2003.

3

        U.S. Bank National Association is the Exchange Agent for the offer and will process tenders and withdrawals of Old Notes in the exchange offer. All executed letters of transmittal and notices of guaranteed delivery should be directed to the Exchange Agent and questions or requests for assistance or additional copies of the original prospectus and this prospectus supplement and related letter of transmittal may be directed to it at one of its addresses set forth below:

U.S. BANK NATIONAL ASSOCIATION

By Mail: U.S. Bank National Association Corporate Trust Services (Silicon Graphics, Inc.) St. Paul, MN 55101	By Facsimile: (651) 244-1537	By Hand or Overnight Courier: U.S. Bank National Association Corporate Trust Services (Silicon Graphics, Inc.) St. Paul, MN 55101
	Confirm Facsimile by Telephone: (651) 244-8161

        The Information Agent for the exchange offer is MacKenzie Partners, Inc. Questions and requests for assistance may be directed to the Information Agent at its address and telephone number set forth below. Additional copies of the original prospectus, the notice of guaranteed delivery and this prospectus supplement and letter of transmittal may also be obtained from the Information Agent.

MacKENZIE PARTNERS, INC.

105 Madison Avenue
New York, New York 10016
Call collect: 212-929-5500
Call toll-free: 800-322-2885

QuickLinks

Prospectus Supplement to Prospectus dated April 21, 2003 and Prospectus Supplement dated May 22, 2003, Prospectus Supplement dated June 30, 2003, Prospectus Supplement dated May 22, 2003 and Prospectus Supplement dated June 30, 2003

SILICON GRAPHICS, INC. SUPPLEMENT TO ITS OFFER TO EXCHANGE 11.75% SENIOR NOTES DUE 2009 OR 6.50% SENIOR CONVERTIBLE NOTES DUE 2009 FOR ALL OUR OUTSTANDING 5.25% SENIOR CONVERTIBLE NOTES DUE 2004
THE EXCHANGE OFFER
IMPACT ON UNAUDITED PRO FORMA INFORMATION
UNAUDITED PRO FORMA INFORMATION
PROCEDURE FOR TENDERING NOTES
U.S. BANK NATIONAL ASSOCIATION

EX-99.(A)(1)(C)

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 99.(a)(1)(C)

SILICON GRAPHICS, INC.
Offer to Exchange for All of Its Outstanding
5.25% Senior Convertible Notes Due 2004 (Cusip No. 827056AC6)
11.75% Senior Notes Due 2009
6.50% Senior Convertible Notes Due 2009

July 16, 2003

To:

Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees

Re:

Solicitation fee to be paid by Silicon Graphics, Inc.

Ladies and Gentlemen:

        Silicon Graphics, Inc. (the "Company") is offering, upon the terms and subject to the conditions set forth in the prospectus dated April 21, 2003 (the "Original Prospectus"), the related letter of transmittal (the "Letter of Transmittal"), and the prospectus supplements dated May 22, June 30 and July 16, 2003 (the "Prospectus Supplements"), which together constitute the Company's offer to exchange (the "Exchange Offer") $1,000 principal amount of its 11.75% Senior Notes Due 2009 (the "New Notes") or $1,000 principal amount of its 6.50% Senior Convertible Notes Due 2009 (the "New Convertible Notes") for each $1,000 principal amount of the Company's outstanding 5.25% Senior Convertible Notes Due 2004 (the "Old Notes").

        Old Notes may be tendered for New Notes, for New Convertible Notes or for any combination thereof. If more than $78 million aggregate principal amount of Old Notes are tendered for New Convertible Notes, the Company will accept Old Notes for exchange on a prorated basis. Old Notes not accepted for exchange for New Convertible Notes because of proration will be exchanged for New Notes.

        The Exchange Offer is subject to various conditions set forth in the Original Prospectus and the Prospectus Supplements, including that at least 85% of the outstanding principal amount of Old Notes be validly tendered and not withdrawn by the expiration of the Exchange Offer.

        Pursuant to the Letter of Transmittal, each tendering holder of Old Notes will represent to, and agree with, the Company that (1) the holder agrees to all of the terms of the Exchange Offer, (2) the holder is the owner of the Old Notes tendered for exchange, (3) the holder has full power and authority to tender, exchange, sell, assign and transfer the Old Notes tendered, (4) when the Old Notes are accepted for exchange, the Company will acquire good, marketable and unencumbered title thereto, free and clear of all liens, restrictions, charges and encumbrances, and that the Old Notes tendered hereby are not subject to any adverse claims or proxies, and (5) the holder will, upon request, execute and deliver any additional documents deemed by the Company or the Exchange Agent to be necessary or desirable to complete the exchange, assignment and transfer of the Old Notes tendered.

        We are requesting that you contact clients for whom you hold Old Notes regarding the Exchange Offer and we will pay brokers, dealers or others soliciting acceptances of the Exchange Offer a solicitation fee (a "Soliciting Dealer Fee"). A Soliciting Dealer Fee will be payable only with respect to tenders by beneficial holders of $250,000 or less principal amount of Old Notes and only with respect to tenders that are accepted in the Exchange Offer.

        The amount of the fee to be paid with respect to tenders that are accepted in the Exchange Offer will be $2.50 per $1,000 principal amount of Old Notes solicited from beneficial holders of more than $50,000 and less than $250,000 principal amount of Old Notes and $5.00 per $1,000 principal amount of Old Notes solicited from beneficial holders of $50,000 principal amount or less of Old Notes.

        For your information and for forwarding to your clients for whom you hold Old Notes registered in your name or in the name of your nominee, we are enclosing the following documents:

1.

Prospectus Supplement dated July 16, 2003; and



2.

A form of letter which may be sent to clients for whose account you hold Old Notes registered in your name or the name of your nominee, with space provided for obtaining such clients' instructions with regard to the Exchange Offer.

YOUR PROMPT ACTION IS REQUESTED. THE EXCHANGE OFFER WILL EXPIRE AT MIDNIGHT, NEW YORK CITY TIME, ON AUGUST 1, 2003. TENDERS OF OLD NOTES MAY BE WITHDRAWN UNTIL THE EXPIRATION DATE.

        Any requests for additional copies of the enclosed materials should be directed to MacKenzie Partners, Inc., the information agent for the Exchange Offer, at the telephone numbers set forth below.

The Information Agent for the Exchange Offer is:
MacKenzie Partners Inc.
105 Madison Avenue
New York, New York 10016
(212) 929-5500 (Call Collect)
or
Call Toll-Free (800) 322-2885

Very truly yours.

SILICON GRAPHICS, INC.

        NOTHING HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU OR ANY PERSON AS AN AGENT OF THE COMPANY OR THE EXCHANGE AGENT, OR AUTHORIZE YOU OR ANY OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY STATEMENTS ON BEHALF OF EITHER OF THEM WITH RESPECT TO THE EXCHANGE OFFER, EXCEPT FOR STATEMENTS EXPRESSLY MADE IN THE ORIGINAL PROSPECTUS, THE LETTER OF TRANSMITTAL OR THE PROSPECTUS SUPPLEMENTS.

Enclosures

2

NOTICE OF SOLICITED TENDERS

        List below the principal amount of Old Notes tendered by each beneficial owner whose tender you have solicited. All Old Notes beneficially owned by a beneficial owner, whether in one account or several, must be aggregated for purposes of completing the table below. Any questions as to what constitutes beneficial ownership should be directed to the Information Agent. If the space below is inadequate, list the Old Notes on a separate signed schedule and affix the list to this Notice of Solicited Tenders. Please do not complete the sections of the table headed "TO BE COMPLETED BY THE EXCHANGE AGENT".

ALL NOTICES OF SOLICITED TENDERS SHOULD BE RETURNED TO THE EXCHANGE AGENT AT THE ADDRESS SET FORTH ON THE FRONT OF THE LETTER OF TRANSMITTAL AND IN THE PROSPECTUS SUPPLEMENT WITHIN TWO NEW YORK STOCK EXCHANGE TRADING DAYS AFTER THE EXPIRATION DATE. ALL QUESTIONS CONCERNING THE NOTICES OF SOLICITED TENDERS SHOULD BE DIRECTED TO THE INFORMATION AGENT AT THE TELEPHONE NUMBER SET FORTH HEREIN.

SOLICITED TENDERS OF OLD NOTES
NOT BENEFICIALLY OWNED BY THE SOLICITING DEALER

DTC#

Firm name

VOI # or U.S. Bank Confirmation

Principal Amount

Beneficial Owners		To be Completed by the Soliciting Dealer: Principal Amount Tendered**	To be Completed by the Exchange Agent: Principal Amount Accepted	To be Completed by the Exchange Agent: Fee ($2.50 per $1,000 Principal Amount Accepted)	To be Completed by the Exchange Agent: Fee ($5.00 per $1,000 Principal Amount Accepted)
Beneficial Owner No. 1
Beneficial Owner No.
Beneficial Owner No.
Beneficial Owner No.
Beneficial Owner No.
	Total

**

Please submit a separate VOI Ticket for Old Notes tendered when the solicitation fee is to be directed to another Soliciting Dealer.

        All questions as to the validity, form and eligibility (including time of receipt) of Notices of Solicited Tenders will be determined by the Exchange Agent, in its sole discretion, which determination will be final and binding.

Neither the Exchange Agent nor any other person will be under any duty to give notification of any defects or irregularities in any Notice of Solicited Tenders or incur any liability for failure to give such notification.

3

        The undersigned hereby confirms that (i) it has complied with the applicable requirements of the Securities Exchange Act of 1934, as amended, and the applicable rules and regulations thereunder, in connection with such solicitation; (ii) it is entitled to such compensation for such solicitation under the terms and conditions of the Prospectus Supplement dated May 22, 2003 (unless the undersigned is not being compensated for such solicitation) and (iii) in soliciting tenders of Old Notes, it has used no solicitation materials other than those furnished by the Company.

(Name of Firm)	DTC #
(Authorized Signature)
(Area Code and Telephone Number)
(Address)
(City, State, Zip Code)
(Attention)

Date:

SOLICITING DEALER FEE
PAYMENT INSTRUCTIONS

Issue Check to:

Firm Principal Amount

Attention

Address

Area Code and

Telephone Number

Taxpayer ID

Applicable VOI Number/

U.S. Bank Confirmation No.

4

QuickLinks

Exhibit 99.(a)(1)(C)

SILICON GRAPHICS, INC. Offer to Exchange for All of Its Outstanding 5.25% Senior Convertible Notes Due 2004 (Cusip No. 827056AC6) 11.75% Senior Notes Due 2009 6.50% Senior Convertible Notes Due 2009

EX-99.(A)(1)(D)

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 99.(a)(1)(D)

SILICON GRAPHICS, INC.
Offer to Exchange for All of Its Outstanding
5.25% Senior Convertible Notes Due 2004 (Cusip No. 827056AC6)
11.75% Senior Notes Due 2009
6.50% Senior Convertible Notes Due 2009

July 16, 2003

To Our Clients:

        Enclosed for your consideration is a prospectus supplement dated July 16, 2003 updating the Prospectus dated April 21, 2003 and prospectus supplements dated May 22, 2003 and June 30, 2003 (collectively, the "Prior Prospectuses") relating to the offer (the "Exchange Offer") of Silicon Graphics, Inc. (the "Company") to exchange $1,000 principal amount of its 11.75% Senior Notes Due 2009 (the "New Notes"), or $1,000 principal amount of its 6.50% Senior Convertible Notes Due 2009 (the "New Convertible Notes") for each $1,000 principal amount of the Company's outstanding 5.25% Senior Convertible Notes Due 2004 (the "Old Notes").

        Old Notes may be tendered for New Notes, for New Convertible Notes or for any combination thereof. If more than $78 million aggregate principal amount of Old Notes are tendered for New Convertible Notes, the Company will accept Old Notes for exchange on a prorated basis. Old Notes not accepted for exchange for New Convertible Notes because of proration will be exchanged for New Notes upon the terms and subject to the conditions described in the Prior Prospectuses.

        The Exchange Offer is subject to various conditions set forth in the Prior Prospectuses and the prospectus supplement dated July 16, 2003, including that at least 85% of the outstanding principal amount of Old Notes be validly tendered and not withdrawn by the expiration of the Exchange Offer.

        This material is being forwarded to you as the beneficial owner of the Old Notes held by us for your account but not registered in your name. A TENDER OF SUCH OLD NOTES MAY ONLY BE MADE BY US AS THE HOLDER OF RECORD AND PURSUANT TO YOUR INSTRUCTIONS. If you wish to have us tender your Old Notes, please so instruct us by completing, executing and returning to us the instruction form on the back of this letter. THE LETTER OF TRANSMITTAL WAS FURNISHED TO YOU FOR INFORMATION ONLY AND MAY NOT BE USED DIRECTLY BY YOU TO TENDER OLD NOTES.

        Accordingly, we request instructions as to whether you wish us to tender on your behalf the Old Notes held by us for your account, pursuant to the terms and conditions set forth in the Prior Prospectuses and enclosed prospectus supplement dated July 16, 2003.

        Your instructions should be forwarded to us as promptly as possible in order to permit us to tender the Old Notes on your behalf in accordance with the provisions of the Exchange Offer. The Exchange Offer will expire at midnight, New York City time on August 1, 2003. Any Old Notes tendered pursuant to the Exchange Offer may be withdrawn at any time before the Expiration Date.

        Your attention is directed to the following:

1.

The Exchange Offer is for any and all Old Notes.



2.

The Exchange Offer is subject to certain conditions set forth in the Prior Prospectuses, including the condition set forth in the prospectus supplement dated July 16, 2003 that at least 85% of the outstanding principal amount of the Old Notes be validly tendered and not withdrawn.



3.

Any transfer taxes incident to the transfer of Old Notes from the holder to the Company will be paid by the Company, except as otherwise provided in the Instructions in the Letter of Transmittal.



4.

The Exchange Offer expires at midnight, New York City time on August 1, 2003.

        We also request that you confirm that we may make on your behalf the representations and undertakings contained in the Letter of Transmittal. Pursuant to the Letter of Transmittal, each holder of Old Notes will represent to the Company that (1) the holder agrees to all of the terms of the Exchange Offer, (2) the holder is the owner of the Old Notes tendered for exchange, (3) the holder has full power and authority to tender, exchange, sell, assign and transfer the Old Notes tendered, (4) when the Old Notes are accepted for exchange, the Company will acquire good, marketable and unencumbered title thereto, free and clear of all liens, restrictions, charges and encumbrances, and that the Old Notes tendered hereby are not subject to any adverse claims or proxies and (5) the holder will, upon request, execute and deliver any additional documents deemed by the Company or the Exchange Agent to be necessary or desirable to complete the exchange, assignment and transfer of the Old Notes tendered.

2

INSTRUCTIONS WITH RESPECT TO
THE EXCHANGE OFFER

        The undersigned acknowledge(s) receipt of your letter and the enclosed material referred to therein relating to the Exchange Offer made by Silicon Graphics, Inc. with respect to its Old Notes.

        This will instruct you to tender the Old Notes held by you for the account of the undersigned, upon the terms and subject to the conditions set forth in the Prior Prospectuses, the related Letter of Transmittal and the enclosed prospectus supplement dated July 16, 2003.

        Please tender the Old Notes held by you for my account as indicated below:

	Aggregate Principal Amount of Old Notes
5.25% Senior Convertible Notes Due 2004
Dated:                    , 2003
SIGN HERE
Signature(s)
Please print name(s) here
Address(es)
Area Code and Telephone Number
Tax Identification or Social Security No(s).

Unless a specific contrary instruction is given in the space provided, your signature(s) hereon shall constitute an instruction to us to tender all Old Notes held by us for your account.

3

ACKNOWLEDGEMENT OF SOLICITATION

Please designate in the box below any Soliciting Dealer who solicited your tender.

SOLICITED TENDERS

        As described in the prospectus supplement dated May 22, 2003 in the section captioned "The Exchange Offer—Amended Terms of the Exchange Offer—Retail Solicitation Fee", a solicitation fee will be paid to a Soliciting Dealer (a "Soliciting Dealer Fee"), subject to certain conditions. A Soliciting Dealer Fee will be payable only in connection with tenders of Old Notes that are accepted for exchange from beneficial owners who own no more than $250,000 principal amount of Old Notes.

        The undersigned represents that the Soliciting Dealer who solicited and obtained this tender is:

Name of Firm: (Please Print)

Name of Individual Broker or Financial Consultant:

Identification Number (if known):

Address:

(Including Zip Code)

Telephone Number (if known):

4

QuickLinks

Exhibit 99.(a)(1)(D)

SILICON GRAPHICS, INC. Offer to Exchange for All of Its Outstanding 5.25% Senior Convertible Notes Due 2004 (Cusip No. 827056AC6) 11.75% Senior Notes Due 2009 6.50% Senior Convertible Notes Due 2009