Exhibit 32.1

FORM OF 906 CERTIFICATION

The certification set forth below is being submitted to the Securities and Exchange Commission in connection with the Report on Form 10-Q (the “Report”) for the purpose of complying with Rule 13a-14(b) or Rule 15d-14(b) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code.

Dennis McKenna, the Chief Executive Officer and Jeffrey V. Zellmer, the Chief Financial Officer of Silicon Graphics, Inc., each certifies that, to the best of his knowledge:

1. the Report fully complies with the requirements of Section 13(a) or 15(d) of the Exchange Act; and

2. the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Silicon Graphics, Inc.

Date: February 8, 2006

/s/ Dennis McKenna

Name: Dennis McKenna

Chief Executive Officer

/s/ Jeffrey V. Zellmer

Name: Jeffrey V. Zellmer

Chief Financial Officer