Quote:
Originally Posted by
edalbkrad 
ok so whats the difference between a cpu that is 64 bit compared to a gpu that is 512 bit?
wouldnt it be faster to use 512bit like modern gpus?
Not if you are running 32 or 64 bit code

The modern GPUs are not "real" 512 bit processors as they are using that "512 bit" to just run massive amounts of shorter actions in parallel. A true 512 bit processor would be one executing a native fully 512 bit code, which, for most things done on desktop would be a huge waste.
Edit: to answer your first question, the difference is mainly in how long is the "word" a CPU is executing, i.e., 64 bit or larger. For example, modern CPU's can, actually, run for example two 32 bit actions, if they are compatible and similar enough with one cycle by combining them into a one 64 bit word. Same could be done ofc with longer words as well, buy, for example, running four 32 bit actions in one cycle in 128 bit CPU, however, it increases the complexity of stuff and in the end you end up losing some performance if you are running code where its hard to find four 32 bit snippets to execute simultaneously. Similar how it's often kinda hard to take advantage of all the cores the CPU has as its somewhat similar to the problems one is facing when paralellizing code, just at level closer to hardware.
Edited by Carniflex - 6/26/12 at 9:33am