According to a story posted over at Fudzilla, there are new details leaking out about the February release of the AMD Radeon HD 7700-series of graphics cards.  Based on the 28nm Cape Verde chip we first heard about last month at the AMD GPU Tech Day in Austin, this is the smallest die based on the new Southern Islands architecture.  If you haven’t read about all the changes that SI brings to the table (and there are many) then you should check out our Radeon HD 7970 review while you’re here.

The specifications of the Radeon HD 7700 (Cape Verde XT) according to the leak are 896 stream processors (14 CUs), 56 texture units and 16 ROPs with a clock speed of 900 MHz.  The memory system will be based around 1GB of GDDR5 on a 128-bit memory bus at a 1375 MHz clock rate for a total bandwidth of 88 GB/s.  The Radeon HD 7750 (Cape Verde Pro) steps down to 832 stream processors (13 CUs), 52 texture units and 16 ROPs with a 900 MHz clock speed.  The memory system will still be 128-bit with slightly slower memory for a total of 80 GB/s of bandwidth.

Compared to the Radeon HD 7970, these specs are pretty meager.  The Tahiti GPU has 2048 stream processors and a 384-bit memory bus which would likely make a dramatic difference in performance, as expected  Still, for the estimated $149 price tag AMD could have a winner on its hands.

capeverdediagram-0.jpg

Our estimation of the Cape Verde GPU based on the rumored specifications.  It is also possible that AMD would remove the dual geometry engines at the top and go with a single.

Finally, there is less information about the 7800-series (Pitcairn): it could include a 256-bit memory bus and will obviously include more compute units for its $299 and $249 price tags.  If those leaked prices are legit, that is a HUGE gap in price between the HD 7870 and the HD 7970 currently set to be sold at $549!