Which affects speed more? Processor or RAM?

[Karlos]

A little OT, but I don't really like this fashion statement of sorts that RAM speeds up a computer. That's just not true. If you do anything that actually requires speedy system RAM is not gonna help you - that's why they call these tasks CPU intensive. As for the user experience as the whole, sure, it gets better, because you don't have to wait for the computer that much, but it doesn't give you more FPS in a game.

Actually, that's completely untrue for modern games. I noticed a significant improvement just by increasing the amount of RAM in my main gaming system from 2GB to 4GB. The reason is that a lot of modern games (particularly "open" environment ones like Fallout 3, Crysis etc) use very large datasets that generally can't all be loaded at once and so stuff has to be paged in and out as needed. More RAM, less reloading of data from disk, better performance.

[Karlos]

@koshman

My experience is that, depending on the settings I use in a game, additional RAM almost always helps - from the odd loading jerkiness to the ability to keep large textures cached in RAM for longer. However, I grant you it doesn't just make things "faster", instead it helps stop them from getting slower, by mitigating latencies from parts of an application that might otherwise have to go to disk to retrieve something.

EDIT: I completely agree that the game can be more enjoyable with more RAM, but it doesn't technically run faster - if the screen refresh during combat is low, buying more RAM doesn't solve that.

Well, again, that also depends on your settings and quantity of RAM of the "right sort" can make a big difference. Try playing games that use large graphical datasets on identical GPUs but with different amounts of video RAM. Without enough dedicated ram on the graphics card, frame rates can plummet through the floor as data is streamed constantly from system ram into the graphics card.

Now, regarding the Amiga, there is a definite case that adding RAM can improve performance markedly. Just try using any 68020+ with Chip RAM only