CPU cache; RAM and FSB speed

[Wizrdwarts]

How does much CPU cache affect performance? How much would be enough for gaming, and would you notice a difference with 3mb vs 6mb?

Also, what's the relation between FSB and RAM speed? I've heard people say that when OCing you should keep the ratio 1:1, but I've seen people say thier's on5:4 and 6:5 ratios too.

[=98=]

Re: CPU cache; RAM and FSB speed

Memory ratios doesn't really make a difference.

CPU cache does make a noticeable difference. Don't know why, it just does.

[Wizrdwarts]

Re: CPU cache; RAM and FSB speed

So what's all this about needing good RAM to overclock then? I thought if you kept your RAM speed too low it would pull back the CPU.

[=98=]

Re: CPU cache; RAM and FSB speed

Ratios mean nothing, speeds do.

The faster the RAM you get, the greater front side bus speed you can achieve. With slower RAM, when you increase the FSB, you'll have to overclock the memory. With faster memory, it can run at standard speed (not overclocked) with a higher front side bus.

[Wizrdwarts]

Re: CPU cache; RAM and FSB speed

Another question, how come CPU-Z shows 3 different sets of timings and speed for my RAM?

[Warhawk]

Re: CPU cache; RAM and FSB speed

^^ it is showing the different speed that your memory can run at safely and the appropriate timing for each speed.

[=98=]

Re: CPU cache; RAM and FSB speed

Slow RAM is sloooooooooooooooooooooooooow

[Wizrdwarts]

Re: CPU cache; RAM and FSB speed

Wait, what? I could've sworn my Dell came with PC5300 RAM. Anyways, it is a 2 year old Dell, what do you expect?

[=98=]

Re: CPU cache; RAM and FSB speed

Wait, what? I could've sworn my Dell came with PC5300 RAM. Anyways, it is a 2 year old Dell, what do you expect?

It does.

It's DDR2 so multiply the numbers by 2 for the real speed.

[Wizrdwarts]

Re: CPU cache; RAM and FSB speed

It says PC2-4200 right there... Besides, Wikipedia says 200mhz is PC2-3200 and 266mhz is PC2-4200/4300.

If I doubled it I'd have DDR2-1066.

[=98=]

Re: CPU cache; RAM and FSB speed

Your RAM is PC-4300 which in reality, is 533mhz. It says 266mhz x 2 (DDR2) = 533mhz

[Wizrdwarts]

Re: CPU cache; RAM and FSB speed

That still doesn't make it PC-5200 though.

http://en.wikipedia.org/wiki/DDR2#Chips_and_modules

[=98=]

Re: CPU cache; RAM and FSB speed

That still doesn't make it PC-5200 though.

http://en.wikipedia.org/wiki/DDR2#Chips_and_modules

Oh wait, i thought you said PC4200. My bad.

You wouldn't notice a difference anyway.

[AvalancheDiode]

Re: CPU cache; RAM and FSB speed

For Intel system with large L2 cache, RAM speed is not as important, though faster RAM is always good for overclocking.

For AMD system, RAM speed is critical. Current AMD CPUs have lower L2 or L3 cache, so faster RAM can actually enhance overall performance by noticeable margin. I ran HyperPi on my 4850e with 800 and 1066 speed, and there is 1 second difference out of 37.