NVIDIA decided to mix some Fermi and Kepler GPUs to this entry-level segment. The most powerful of those cards is GeForce GT 645, based on Fermi GF114, the very same GPU known for recently released GTX 560 SE.
There are also three variants of GeForce GT 640, they differ in memory type, bus width and GPU used. Two of them are using brand new Kepler GK107 GPU, which is featuring 384 CUDA cores, 24 TMUs and 16 ROPs. Core clock varies from 720 MHz on Fermi chip to 950MHz on Kepler. The GT 640 based on GF116 will feature up to 3 GB of GDDR3 ram.
It all gets interesting when we compare GeForce GT 630 with the slowest GT 640. Both cards are based on the same GK107 GPU, but surprisingly, GT 630 is actually better and will feature better performance as a result.
All of those cards are however intended for OEMs only. On the contrary, we should expect retail GK107 cards in near future.
|GeForce GT 630||GeForce GT 640||GeForce GT 640||GeForce GT 640||GeForce GT 645|
|Core Clock:||875 MHz||797 MHz||720 MHz||950 MHz||776 MHz|
|Shaders Clock:||875 MHz||797 MHz||1440 MHz||950 MHz||1552 MHz|
|Memory Clock:||891 MHz||891 MHz||891 MHz||2500 MHz||1914 MHz|
|Memory Type:||1 or 2GB GDDR3 128-bit||1 or 2GB GDDR3 128-bit||1.5 or 3GB GDDR3 192-bit||1 or 2GB GDDR5 128-bit||1GB GDDR5 128-bit|
|Memory Bandwidth||28.5 GB/s||28.4 GB/s||43 GB/s||80 GB/s||91.9 GB/s|
|TDP:||50 W||50 W||75 W||75 W||140 W|