The new GeForce GTX 680MX and GTX 675MX are equipped with more CUDA cores than their M variants. GeForce GTX 680MX is now considered the fastest mobile GPU, since it has full 1536 CUDA cores known from desktop GTX 680 with Kepler GK104. Also the GTX 675MX and GTX670MX have two-and-half times more cores than GTX 670M — 960.
Both GPUs feature higher memory clocks, while retaining the original configuration. GeForce GTX 680MX and GTX675MX support GDDR5 memory across 256-bit interface, while the GTX 670MX is crippled to 192-bit (same as GTX670M). Interestingly the new GTX675MX is operating only with PCI-Express 2.0 bus (only GTX680xx models have PCI-E 3.0 support).
NVIDIA has announced that these two processors will be installed with the new 27-inch iMacs.
The new 27-inch iMac offers the GeForce GTX 660M as its base GPU, with even faster GeForce GTX 675MX or GeForce GTX 680MX GPUs available. The 21.5-inch model comes with the GeForce GT 640M GPU, with an available upgrade to the GeForce GT 650M GPU.
The new 27-inch iMac with GTX675MX and GTX680MX will be available in December, starting from $1799.
|GeForce Mobile GPUs||GTX 680MX||GTX 680M||GTX 675MX||GTX 675M||GTX 670MX||GTX 670M|
|GPU Clock||720 MHz||720 MHz||600 MHz||620 MHz||600 MHz||598 MHz|
|Memory Clock||2500 MHz||1800 MHz||1800 MHz||1500 MHz||1400 MHz||1500 MHz|
|Memory Interface||GDDR5 256-bit||GDDR5 256-bit||GDDR5 256-bit||GDDR5 256-bit||GDDR5 192-bit||GDDR5 192-bit|
|Memory Bandwidth||160.0 GB/s||115.2 GB/s||115.2 GB/s||96.0 GB/s||67.2 GB/s||72.0 GB/s|
|Texture Fillrate||92.2 (billion/s)||80.6 (billion/s)||48.0 (billion/s)||39.7 (billion/s)||48.0 (billion/s)||33.5 (billion/s)|