How much does the speed of RAM really matter?

[JogaBonito1502]

We're always talking about how the faster your RAM is the better and such. Then there's this deal with RAM:CPU ratio when OC'ing. Now I'm wondering whether the size of the RAM or the speed matters the most. Because I got this gateway and everything in the motherboard's awesome, except the RAM. It's DDR, and it came with 1GB clocked at 400MHz. Now, I know there's probably a huge difference from this when compared to DDR2 @ 800MHz, but how much of it is really noticeable?

 

[Teny]

to me, i noticed a difference.
when i was running the 400mhz DDR ram 768 mb (1 512mb, 1 256 mb)
then when i switched to 667mhz DDR2 512 mb, its about the same, slightly faster, but not by much.
Then i went to 3gb at the speed of 667 mhz with CAS5 (Cheap PNY), and my computer ran great, i think it got like a 5.6 on vista ratings.
Then i sold them and got 2gb at the speed of 800 mhz with CAS4 (XMS2) and dual channeled, it somehow felt like it went faster. It even got an 5.9 on vista rating.
So i guess going from DDR (400mhz) to DDR2 (667mhz) theres a slight increase for me.
then from 667mhz to 800mhz, it performed faster.
I would rather go with speed than size.
But then again, it depends on what you are doing.

 

[an0nym0us1]

as long as you're running 1:1 divider you're going to experience good bandwidth through your sticks. the most important thing when looking at ram is the CAS latencies at the rated speeds. i'd rather run DDR2 667 sync-ed with a 1333fsb cpu with 3-3-3-8 timings than with a multiplier that yields DDR2 800 speeds with 4-4-4-12 timings.

 

[Teny]

hmm, from what i heard from people on this forums is that the CAS doent really matter if you use it on small resolution (1024 x 768 i think)
but when on higher resolutions (1650 x 1080) the CAS dont really matter.
But i still went with better CAS because i wanted too, but somehow its set to 5-5-5-18 while its suppose to be 4-4-4-13.
I dont know if i should change it through the BIOS, would it count as OCing when i change it to 4-4-4-13 if its originally CAS4?

 

[an0nym0us1]

hmm, from what i heard from people on this forums is that the CAS doent really matter if you use it on small resolution (1024 x 768 i think)
but when on higher resolutions (1650 x 1080) the CAS dont really matter.
But i still went with better CAS because i wanted too, but somehow its set to 5-5-5-18 while its suppose to be 4-4-4-13.
I dont know if i should change it through the BIOS, would it count as OCing when i change it to 4-4-4-13 if its originally CAS4?

what does screen resolution have to do with latency through the ram. the higher the latency, the slower the machine... period. no, it doesn't count as overclocking. it's called tightening your timings, technically overclocking is actually clocking the cpu, ram or gpu to a higher speed than it was meant to be run at. once again, critical thinking is the issue at hand here, don't just blindly listen to other posters' flawed logic and assume that it is the truth. get a definitive reason why their reasoning is true, then accept it as truth.

 

[Teny]

I kind of thought it was weird how the higher timings are used for resolutions.
My friends told me the same thing you told me.
but a mod told me that CAS latency doesnt really give much performance, though the lower is better.

 

[worshipme]

It depends if this is with an Intel platform or AMD.

With an Intel platform, the memory bandwidth can never surpass the FSB, for example, running the FSB at 400 MHz, that's DDR 800. Running the RAM at DDR 1066 will not increase the bandwidth as the FSB is the bottleneck.

AMD CPUs have an integrated memory controller that allows much higher bandwidth to the memory.

 

[JogaBonito1502]

I'm going to be using an AMD machine.