GPU: Core clock vs. Shader Clock overclocking?

[TechyInAZ]

Hi all! I always hear you overclock both the core clock and the shader clock, but what is the shader and why is it so important to overclock that?

 

[Spaniard United]

Shader does all of the actual computation for rendering. It's the brawn within the brain.

 

[hunter315]

Most GPUs have now combined the shader clock and the core clock, but the shaders perform the actual operations on the pixels while the core handles the math to figure out what should be done to the pixels. It doesn't matter how fast the core is if the shaders cannot keep up and it doesn't matter how fast the shaders are if the core cannot feed them, you must keep things in balance.

 

[TechyInAZ]

ah, I thought shader was the vram this whole time LOL.

 

[17seconds]

On an overclocking application, like Afterburner, the shader clock is not shown and is not available for modifying. This is because the shader/CUDA clocks are locked and are exactly the same as the core clock, that is, on all AMD cards and recent vintage Nvidia video cards. Fermi generation and prior Nvidia cards had "hot clocks", which only meant that the shader clocks were 2x the core clock (as opposed to 1x the core clock on modern models). The memory clock is another name for the VRAM clock speed.