SUMMARY CONSOLIDATED FINANCIAL DATA

          The summary consolidated balance sheet data as of March 31, 2009 have been derived from our unaudited consolidated financial statements that are incorporated by reference in this prospectus. In the opinion of management, such unaudited quarterly financial data contains all adjustments necessary for the fair statement of our financial position as of and for such periods.

          The as adjusted balance sheet data column gives effect to the issuance and sale of the notes in this offering, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us (assuming no exercise of the underwriters’ over-allotment option to purchase additional notes), as if such event took place on March 31, 2009. The data should be read in conjunction with the consolidated financial statements, related notes and other financial information incorporated by reference in this prospectus.

		As of March 31, 2009
		Actual				As Adjusted (2)
		(In thousands)
		(Unaudited)
Consolidated Balance Sheet Data(1):
Cash and cash equivalents		$	125,838			$	270,838
Other current assets			231,251				231,901
Total assets			395,292				543,542
Total liabilities			167,045				264,545
Stockholders’ equity			228,247				278,997

USE OF PROCEEDS

          We estimate that the net proceeds from this offering will be approximately $145,000,000 (or $166,937,500 if the underwriters exercise their over-allotment option to purchase additional notes in full), after deducting underwriters’ discounts and commissions and expenses payable by us.

          We intend to use the net proceeds from this offering for general corporate purposes, which may include financing potential acquisitions and strategic transactions, repayment of our zero coupon convertible senior notes due February 2010, and working capital. As part of our strategic initiatives, we currently are evaluating, and expect to engage in, investments in or acquisitions of companies, products or technologies and the entry into strategic transactions or other arrangements. These acquisitions, investments, transactions or arrangements are likely to range in size, but some of them may be significant.  Accordingly, as described above, a portion of the net proceeds of this offering may be used for one or more acquisitions, investments or similar arrangements. 

          Pending application for the foregoing purposes, the net proceeds from this offering will be invested in short-term interest-bearing instruments or other investment grade securities. As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds of this offering. Accordingly, we will retain broad discretion over the use of these proceeds.

CAPITALIZATION

          The following table sets forth our unaudited cash, cash equivalents, zero coupon convertible senior notes due February 2010 and capitalization as of March 31, 2009:

	•		on an actual basis; and
	•		on an as-adjusted basis to give effect to the issuance and sale of the notes in this offering, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us (assuming no exercise of the underwriters’ over-allotment option to purchase additional notes).

          You should read this table in conjunction with “Use of Proceeds” as well as our “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements, including the related notes, incorporated by reference into this prospectus and our Quarterly Report on Form 10-Q for the three months ended March 31, 2009, and our Current Report on Form 8-K filed with the SEC on June 22, 2009, each incorporated by reference herein.

		March 31, 2009
		Actual				As Adjusted
		(In thousands, except share
		amounts)
		(Unaudited)
Cash, cash equivalents and marketable securities		$	347,928			$	492,928
Zero coupon convertible senior notes due February 2010		$	128,034			$	128,034
Long term debt:
Notes offered hereby (1)		$	—			$	97,500
Stockholders’ equity:
Convertible preferred stock, $0.001 par value. 5,000,000 shares authorized, no shares issued or outstanding, actual and as adjusted			—				—
Common stock, $0.001 par value. 500,000,000 shares authorized, 104,466,738 shares issued and outstanding, actual, 104,466,738 shares issued and outstanding as adjusted (2)			104				104
Additional paid-in capital (1)			716,908				767,658
Accumulated deficit			(489,098	)			(489,098	)
Accumulated other comprehensive income			333				333
Total stockholders’ equity			228,247				278,997
Total capitalization		$	228,247			$	376,497

Equity component (net of estimated issuance costs)		$	50,750
Liability component:
Principal		$	150,000
Less: debt discount			(52,500	)
Net carrying amount		$	97,500

(2)

Outstanding common stock does not include (i) 16,069,032 shares of common stock that will be issued upon the exercise of outstanding stock options under our stock plans as of March 31, 2009, at a weighted average exercise price of $20.17 per share, (ii) 1,081,712 shares of common stock available for grant under our stock option plans (in addition to 6,500,000 shares reserved for issuance under the 2006 Equity Incentive Plan which were approved at the 2009 Annual Meeting of Stockholders on April 30, 2009), (iii) 1,265,071 shares reserved for issuance under our Employee Stock Purchase Plan, (iv) zero shares of common stock issuable upon the conversion of our zero coupon convertible senior notes due February 2010 currently

outstanding given the price of our common stock for the applicable conversion reference periods as of March 31, 2009, and (v) zero shares of common stock issuable upon conversion of the notes offered hereby given the price of our common stock for the applicable conversion reference periods as of March 31, 2009.

Supplemental litigation disclosure

As described in the prospectus, on May 5, 2004, Rambus filed a lawsuit against Micron, Hynix, Infineon and Siemens in San Francisco Superior Court seeking damages for conspiring to fix prices (California Bus. & Prof. Code §§ 16720 et seq.), conspiring to monopolize under the Cartwright Act (California Bus. & Prof. Code §§ 16720 et seq.), intentional interference with prospective economic advantage, and unfair competition (California Bus. & Prof. Code §§ 17200 et seq.). On June 17 and 22, 2009, Micron, Samsung and Hynix filed petitions requesting that the court of appeal issue writs directing the trial courts to vacate two orders denying motions for summary judgment and enter orders granting the motions. On June 19, 2009, Micron and Samsung filed petitions requesting that the court of appeal issue writs directing the trial court to vacate its order denying the defendants’ motion for issue preclusion and termination sanctions and enter an order granting the motion. No decisions have issued to date on any of these petitions.