The Geforce GTX 675MX leads the pack
has silently updated its mobile GPU lineup with four new GPUs that should eventually start to appear in select notebooks. The lineup brings back the well known Nvidia MX moniker and includes the GTX 675MX, GTX 670MX, GT 645M and GT 625M.
We'll start with the GT 645M and the GT 625M as these are simply updated versions of the GT 640M and the GT 620M GPUs. The GT 645M has the same 384 CUDA cores as the GT 640M but works at slightly higher 710MHz for the GPU. It will still be available with both DDR3 and GDDR5 memory paired up with a 128-bit memory interface. The GT 625M also feature the same 96 CUDA cores as the GT 620M and works at the same 625MHz for the GPU. The only difference that we can see on Nvidia's specification list is that although it uses the same DDR3 memory, the memory interface is listed at "up to 128-bit", adding to a higher 28.8GB/s memory bandwidth.
The GTX 675MX and GTX 670MX are a bit more interesting, as they are quite different than the GTX 675M and the GTX 670M. Both are based on the 28nm Kepler GPUs and features 960 CUDA cores. According to what we can gather from the specs, the GTX 675MX appears to be based on a crippled GK104 GPU while the GTX 670MX is based on the GK106 one. The GTX 675MX works at 600MHz for the GPU and comes with GDDR5 memory clocked at 1800MHz and paired up with a 256-bit memory interface adding up to 115.2GB/s of memory bandwidth. The GTX 670MX works at the same 600MHz for the GPU but comes with GDDR5 memory clocked at 1800MHz and paired up with a 192-bit memory interface adding up to 67.2GB/s of memory bandwidth.
Nvidia's mobile lineup is slowly getting a bit crowded and with all the variations one should closely check the specs of the GPU inside the new notebook. The new lineup is expected to show up in new notebooks pretty soon.
You can check out more details at Nvidia's site