Thinking about overclocking a 5830 i recently bought. Just wondering what the differences bw Shader, Memory, and Core clocks are. How do they factor into performance, and is it (relatively) safe to try and overclock all three of them? I usually hear only the memory and core clocks being overclocked
As an AMD card there is no separate shader clock. The shaders are in the core, and there is no separate control for them. Nvidia cards have this option but not AMD cards.
Upping the clock speeds will provide better scores, but usually only just. If you can OC the core by 10%, any games that needed more shading power will see up to 10% better scores. This means that if X game gives you 30FPS and needs more shading power you can see up to 33FPS when your done. The same would be true for memory restricted games. Games that needed more memory bandwidth will show increases as well.
Some cards OC better then others, and not all games will respond to the OC the same. Up to you to find out if they do, and if the increase in power and temps is worth it.