If you were hoping the new generation of 28-nm Radeon GPUs would herald $150 offerings with 256-bit memory interfaces, sorry to disappoint. A story posted by Fudzilla earlier this morning quotes detailed specifications for upcoming Radeon HD 7770 and 7750 graphics cards purportedly due in February, and it says both will be saddled with 128-bit paths to GDDR5 memory, just like their predecessors.
The Radeon HD 7770 will cost $149, Fudzilla says; it will have 896 ALUs (or stream processors), will filter 56 textures per clock, and will churn out 16 pixels per clock. That would be 96 more ALUs and 16 more textures per clock than the Radeon HD 5770 and 6770, which are both based on the 40-nm Juniper GPU. Fudzilla also claims the 7770 will have a 900MHz GPU clock speed and 1375MHz GDDR5 clock speed. The 6770, by contrast, typically runs at 850MHz with 1200MHz GDDR5 RAM.
Word is that there will also be a $139 Radeon HD 7750 with fewer bits and pieces and slower memory, but if it's really only $10 cheaper, I'm not sure I see the appeal.
Either way, if Fudzilla has its facts straight, the move to 28-nm may not herald much of a performance improvement in that part of the Radeon lineup. Heck, right now, $150 will buy you a full-fledged Radeon HD 6850, which is quite a bit faster than the Radeon HD 6770—and thus presumably quicker than the rumored 7770. If this report is true, I can only hope the Radeon HD 7770 won't linger at $149 very long.