Why GPU speed are slower them CPU speed? 700Mhz versus 3000Mhz.?

Question

Why GPU speed are slower them CPU speed? 700Mhz versus 3000Mhz.?

Answer 1

Several reasons for that:

1. Those 700 Mhz are dedicated to doing one thing only - 3D processing.

2. They have their own dedicated memory which is on the same PCB (printed circuit board) as the GPU, therefore it has direct access to the memory. Compared to the distance between the RAM slots which your CPU uses, the distance between the GPU and its RAM is much smaller which makes a lot of difference when it comes down to access time.

3. The RAM on video cards is getting faster and faster than system memory. Example - current GPUs use GDDR3 while Intel's maps show that they will start using DDR3 for system memory in 2007.

4. Interrupts are another reason why GPUs don't need speeds that great. The CPU is interrupted by lots of things - every keystroke on your keyboard, your audio card if it is integrated in your motherboard, etc. In comparison, the GPU is not, so it does not have to share its computing power with anything else.



I hope that answered your question.

Answer 2

GPU's are slower then CPUs for 2 main reason, one being that a GPU has one specific processing function while a CPU does an insane amount. Another critical is space, and cooling.



The heatsink on a CPU is massive, you can indeed get a GPU up to 1.5 Gh/z with watercooling.



Space is also very important, the side of a GPU is about the 3rd of a CPU this making it easier to place in a PCI, or AGP slot.

Answer 3

because CPU's calculate any mathematical operation, vs the GPU that only calculates graphical operations, mainly 3D.