The carrying value of our non-marketable equity investment portfolio, excluding equity derivatives, totaled $4.1 billion as of December 27, 2008 ($3.4 billion as of December 29, 2007). The majority of the balance as of December 27, 2008 was concentrated in companies in the flash memory market segment and wireless connectivity market segment. Our flash memory market segment investments include our investment in IMFT of $1.7 billion ($2.2 billion as of December 29, 2007), our investment in IM Flash Singapore, LLP (IMFS) of $329 million ($146 million as of December 29, 2007), and our investment in Numonyx of $484 million. Our wireless connectivity market segment investments include our non-marketable investment in Clearwire LLC of $238 million (see "Note 5: Available-for-Sale Investments" in Part II, Item 8 of this Form 10-K for information on our additional marketable equity investment in the new Clearwire Corporation of $148 million). In addition, we regularly invest in non-marketable equity instruments of private companies, which range from early-stage companies that are often still defining their strategic direction to more mature companies with established revenue streams and business models. For additional information, see "Note 6: Equity Method and Cost Method Investments" in Part II, Item 8 of this Form 10-K.

Our non-marketable equity investments are recorded using adjusted historical cost basis or the equity method of accounting, depending on the facts and circumstances of each investment (see "Note 2: Accounting Policies" in Part II, Item 8 of this Form 10-K). Our non-marketable equity investments are classified in other long-term assets on the consolidated balance sheets.

Non-marketable equity investments are inherently risky, and a number of the companies in which we invest are likely to fail. Their success is dependent on product development, market acceptance, operational efficiency, and other key business factors. Depending on their future prospects, the companies may not be able to raise additional funds when needed or they may receive lower valuations, with less favorable investment terms than in previous financings, and our investments would likely become impaired. Additionally, the current financial markets are extremely volatile and there has been a tightening of the credit markets, which could negatively affect the prospects of the companies we invest in, their ability to raise additional capital, and the likelihood of our being able to realize value in our investments through liquidity events such as initial public offerings, mergers, and private sales. For further information about our investment portfolio risks, including those specific to our investments in the flash memory market segment and wireless connectivity market segment, see "Risk Factors" in Part I, Item 1A of this Form 10-K.

We review our investments quarterly for indicators of impairment; however, for non-marketable equity investments, the impairment analysis requires significant judgment to identify events or circumstances that would significantly harm the fair value of the investment. The indicators that we use to identify those events or circumstances primarily include:

• the investee's revenue and earnings trends relative to predefined milestones and overall business prospects;
• the technological feasibility of the investee's products and technologies;
• the general market conditions in the investee's industry or geographic area, including adverse regulatory or economic changes;
• factors related to the investee's ability to remain in business, such as the investee's liquidity, debt ratios, and the rate at which the investee is using its cash; and
• the investee's receipt of additional funding at a lower valuation.

Investments that we identify as having an indicator of impairment are subject to further analysis to determine if the fair value of the investment is below our carrying value. If the fair value of the investment is below our carrying value, we determine if the investment is other than temporarily impaired based on the severity and duration of the impairment. If the investment is considered to be other than temporarily impaired, we write down the investment to its fair value. Beginning in the first quarter of 2008, the assessment of fair value for non-marketable investments is based on the provisions of Statement of Financial Accounting Standards (SFAS) No. 157, "Fair Value Measurements" (SFAS No. 157), as amended. With the exception of Clearwire LLC, we classified our impaired non-marketable investments as Level 3, as we use unobservable inputs to the valuation methodology that are significant to the fair value measurement, and the valuation requires management judgment due to the absence of quoted market prices and inherent lack of liquidity. We classified our investment in Clearwire LLC as Level 2, as the unobservable inputs to the valuation methodology were not significant to the fair value measurement. See "Note 3: Fair Value" in Part II, Item 8 of this Form 10-K.

Impairments of non-marketable equity investments were $1.2 billion in 2008. Over the past 12 quarters, including the fourth quarter of 2008, impairments of non-marketable equity investments have ranged from $10 million to $896 million per quarter.

The following is a discussion of the methods, estimates, and judgments that management uses in our analysis to determine if our non-marketable equity investments are other than temporarily impaired.

IMFT/IMFS

IMFT and IMFS are variable interest entities that are designed to manufacture and sell NAND products to Intel and Micron at manufacturing cost. Our NAND Solutions Group operating segment purchases 49% of these NAND products from IMFT and sells them to our customers. As a result, we generate cash flows from our investments in IMFT, IMFS, and our intangible assets related to the NAND product designs through our NAND Solutions Group business. Therefore, we determine the fair value of our investments in IMFT and IMFS using the income approach, based on a weighted average of multiple discounted cash flow scenarios of our NAND Solutions Group business.

The discounted cash flow scenarios require the use of unobservable inputs, including assumptions of projected revenues (including product volume, product mix, and average selling prices), expenses, capital spending, and other costs, as well as a discount rate. Estimates of projected revenues, expenses, capital spending, and other costs are developed by IMFT, IMFS, and Intel using historical data and available market data. Management also determines how multiple discounted cash flow scenarios are weighted in the fair value determination. Additionally, the development of several inputs used in our income model (such as discount rate and tax rate) requires the selection of comparable companies within the NAND flash memory market segment. The selection of comparable companies requires management judgment and is based on a number of factors, including NAND products and services lines within the flash memory market segment, comparable companies' sizes, growth rates, and other relevant factors. Based on our fair value determination, the fair value of our investment in IMFT and IMFS approximated carrying value as of December 27, 2008.

Changes in management estimates to the unobservable inputs would change the valuation of the investment. The estimates for the projected revenue and discount rate are the assumptions that most significantly affect the fair value determination. For example, the impact of a 5% decline in projected revenue in each of our cash flow scenarios could result in a decline in the fair value of our investment of up to approximately $300 million. The impact of a one percentage point increase in the discount rate would result in a decline in the fair value of our investment of approximately $225 million.

The fair value determined by the income approach is compared to the carrying value of our investments in IMFT and IMFS and our intangible asset related to the NAND product designs that we purchased from Micron as part of the formation of IMFT. We did not have an other-than-temporary impairment on our investments in IMFT and IMFS in 2008, 2007, or 2006.

Numonyx

We determine the fair value of our investment in Numonyx using a combination of the income approach and the market approach. The income approach includes the use of a weighted average of multiple discounted cash flow scenarios of Numonyx, which requires the use of unobservable inputs, including assumptions of projected revenues, expenses, capital spending, and other costs, as well as a discount rate calculated based on the risk profile of the flash memory market segment. Estimates of projected revenues, expenses, capital spending, and other costs are developed by Numonyx and Intel. The market approach includes using financial metrics and ratios of comparable public companies, such as projected revenues, expenses, and other costs. The selection of comparable companies used in the market approach requires management judgment and is based on a number of factors, including NOR products and services lines within the flash memory market segment, comparable companies' sizes, growth rates, and other relevant factors.

Changes in management estimates to the unobservable inputs in our valuation models would change the valuation of the investment. The estimated projected revenue is the assumption that most significantly affects the fair value determination. For example, the impact of a 5% decline in projected revenue to each of our models and cash flow scenarios could result in a decline in the fair value of our investment of up to approximately $140 million. Management judgment is involved in determining how the income approach and the market approach are weighted in the fair value determination. Our fair value determination was more heavily weighted toward the market approach due to the comparability of similar companies in the market and the availability of market-based data. Increasing the relative weighting of the income approach would have resulted in a decline in the fair value of our investment by approximately $30 million.

We recorded a $250 million impairment charge on our investment in Numonyx during the third quarter of 2008 to write down our investment to its fair value. Estimates for revenue, earnings, and future cash flows were revised lower due to a general decline in the NOR flash memory market segment.

Clearwire LLC

We determine the fair value of our investment in Clearwire LLC primarily using the quoted prices of its parent company, the new Clearwire Corporation. The effects of adjusting the quoted price for premiums that we believe market participants would consider for Clearwire LLC, such as tax benefits and voting rights associated with our investment, were mostly offset by the effects of discounts to the fair value, such as those due to transfer restrictions, lack of liquidity, and differences in dividend rights that are included in the value of the new Clearwire Corporation stock. During the fourth quarter of 2008, we recorded a $762 million impairment charge on our investment in Clearwire LLC to write down our investment to its fair value, primarily due to the fair value being significantly lower than the cost basis of our investment.

In addition, during the fourth quarter of 2008, we recorded a $176 million impairment charge on our available-for-sale marketable investment in the new Clearwire Corporation due to the fair value being significantly lower than the cost basis of our investment.

Other Non-Marketable Equity Investments

We determine the fair value of our other non-marketable equity investments using the market approach and/or the income approach. The market approach includes the use of financial metrics and ratios of comparable public companies. The selection of comparable companies requires management judgment and is based on a number of factors, including comparable companies' sizes, growth rates, products and services lines, development stage, and other relevant factors. The income approach includes the use of a discounted cash flow model, which requires the following significant estimates for the investee: revenue, based on assumed market segment size and assumed market segment share; estimated costs; and appropriate discount rates based on the risk profile of comparable companies. Estimates of market segment size, market segment share, and costs are developed by the investee and/or Intel using historical data and available market data. The valuation of our other non-marketable investments also takes into account movements of the equity and venture capital markets, recent financing activities by the investees, changes in the interest rate environment, the investee's capital structure, liquidation preferences for the investee's capital, and other economic variables. The valuation of some of our investments in the wireless connectivity market segment was based on the income approach to determine the value of the investee's spectrum licenses, transmission towers, and customer lists.

We recorded a total of $200 million of impairment charges in 2008 on our other non-marketable equity investments. Over the past 12 quarters, including the fourth quarter of 2008, impairments of our other non-marketable equity investments have ranged from $10 million to $134 million per quarter.