[citation][nom]Tomfreak[/nom]1. u claim that GT640 DDR5 have higher spec than 660m(we all know it will be higher), but u said is 80gb/s GPU clock 950MHz, I'll like to know where u get the source from? 2. You keep saying that GT640 are very awesome, DDR5 version is likely to beat 7770. Various benchmark has showed that GT640 DDR3 does not even beat 6670. Tomshardware/Anandtech/techpowerup has many benchmarks @ 1280x1024, 1280x800, 1366x768 some without AA/low FXAA/MSAA just to eliminate memory bandwidth bottleneck issue, it does shows GT640 are handicapped by memory bandwidth. But despite that GT640 DDR3 is only capable running around 6670 performance. I highly doubt a DDR5 version can climb over 7770. GT640 DDR5 vs 7750 is more a realistic number. The problem is the chip being too few shaders itself. Unless u can get >50% performance out from just on GPU clock itself I dont see how it is possible. I also hope GT640 can beat 7770, but the benchmark result tells otherwise. You are just being too optimistic on GK107. as for the edit function i dont get this edit function on adding comments via the article.[/citation]
The specs are official Nvidia specs.
http://www.geforce.com/hardware/desktop-gpus/geforce-gt-640-oem/specifications
Also notice how the GT 640 DDR3 has a 50w TDP, not a 75w TDP like the GT 640 DDR3 192 bit and the GT 640 GDDR5.
I have given you everything that you should need to realize that the GT 640 GDDR5 should meet or beat the Radeon 7770. Keep in mind that it would be a small victory and that some of the most highly factory overclocked 7770s would easily surpass a reference GT 640 GDDR5 by much more more than a reference GT 640 GDDR5 would surpass a reference Radeon 7770.
There aren't too few cores. There are 384 Kepler FP32 CUDA cores. By raw core performance comparisons alone, that's ~20% more than the Radeon 7770's 640 because one Kepler FP32 core is about equal to two VLIW4/GCN cores in performance if all else is equal. 640 times 1.2 is 768 and that is twice as much as 384.The GPU itself is more powerful than the Cape Verde when both are at the same frequency if only count the core performance of each GPU.
Also notice how that link specifies that they are OEM. This is why I voiced my concern about whether or not the GT 640 GDDR5 will enter the retail channels and if so, when it will do so.
There aren't any benchmark results that I've seen about the GT 640 GDDR5, so unless you've found some using the latest drivers, you're making that up.
The edit button is shown if you click the text link "Read the comments on the forums" between the comments section and the article.
This card, with current drivers, should be a little faster than the reference Radeon 7770. However, it probably won't be so much faster that you'd see a difference while you're gaming with it. Looking back on when I said quite significantly, I think that I was mistaken. However, the numbers don't lie. It should be a little faster.