AMD said it will cut about 15 percent of its workforce as its fourth quarter forecast came in lower than expected. CEO Rory Read said AMD has been hit by the PC's industry's period of "very significant change."

For the fourth quarter, AMD is now projecting revenue to fall 9 percent from the third quarter, which was also disappointing. A sequential decline in revenue from the third quarter to the fourth quarter is rare for a chipmaker.

AMD's plan is to take out $20 million in expenses in the fourth quarter and $190 million in 2013. Layoffs will be the largest cost savings. AMD said it expects to complete the layoffs in the fourth quarter and take an $80 million restructuring charge.

The company said that it is aiming to have break even operating income at $1.3 billion in quarterly sales.

Read added that "the trends we knew would re-shape the industry are happening at a much faster pace than we anticipated."

As for the third quarter, AMD reported a net loss of $157 million, or 21 cents a share, on revenue of $1.27 billion, down from $1.69 billion a year ago. On a non-GAAP basis, AMD lost 20 cents a share. AMD also said it took a $100 million inventory writedown from tis Llano accelerated processor units. The company already indicated that the third quarter was dreadful .

CNET News reported last week that AMD was prepping layoffs.