more gigabytes ma!

I have enough money to buy an additional 1GB stick of ram but it will only be CL3

I already have 1 GB (2x256) of CL2

Once in a while I use more than my 1GB because I do 3D rendering (SoftImage and trueSpace) but not often.

I realise that my computer will be much faster when it needs more than 1GB ram available at once. That's obvious.

Question 1: how much real world difference does CAS rating make?
Question 2: will the additional ram do anything at all in normal // non maxed out use?

PS this is the ultra cheap memory at hardcooling. Is there something I should know?

What kind of RAM is it? PC3200? PC2100? If you're running PC2100 at CL2 and the ram you want to get is PC3200 then chances are it'll run CL2 at PC2100.

umm, I believe 2X256 = 1/2 gig

In his sig, he lists 2*512 PC2100 at CAS2 . . . Chances are that even the shoddiest PC3200 will do CL2 at PC2100 speeds. As for performance gains, I highly doubt that anything over 1GB will show improved performance, unless you're actually USING more than 1GB of RAM, as the system will then start thrasing the page file. What would make a difference is running at a higher FSB than 133. If you took out the PC2100 and just used a gig of PC3200 @ 400MHz, I think you'd realize a performance gain over what you've got now. But then you're missing any benefit you'd get from 2 gigs of RAM. Unless you're doing something that actually uses that much RAM, though, I'd say you're much better off using PC3200 only . . .

Running at PC3200 speeds will give you a clock speed boost as well, which might be noticable. If you're truly running PC2100 (as your sig says), then you're underclocking your 2500+ by more than 350MHz. I'd say running it at PC3200 is pretty realistic. That's a jump from 1463MHz to 2200MHz (737MHz), which is huge. You won't feel it in Windows or IE, but any app like gaming or encoding or rendering should show a sizable boost.

Z

zachj said:

In his sig, he lists 2*512 PC2100 at CAS2 . . . Chances are that even the shoddiest PC3200 will do CL2 at PC2100 speeds. As for performance gains, I highly doubt that anything over 1GB will show improved performance, particularly because it's going to be what, 4 sticks of RAM? I know P4 performance goes down after 2 sticks (don't remember where I read it, though, so maybe I "know" a lie . . .), and I imagine that might be true for AMDs as well. What would make a difference is running at a higher FSB than 133. If you took out the PC2100 and just used a gig of PC3200 @ 400MHz, I think you'd realize a performance gain over what you've got now. But then you're missing any benefit you'd get from 2 gigs of RAM. Unless you're doing something that actually uses that much RAM, I'd say you're much better off using PC3200 only . . .

Z

Click to expand...

Zach you have a misconception. No offense or anything but I don't want him to get the wrong idea. P4 Dual channel chipsets run great with 4 sticks, actually it's at it's best with 4 sticks of double sided ram. The only downside is overclocking drops off a bit. Overclocking potential drops not performance.

I agree completely with your statement that a gig of PC3200 would be better than 2 gigs of 2100. But His system might not be able to run PC3200 speeds. For now over a gig for the average user shows diminishing returns. However if he does graphics editing or some sort of server, then 2 gigs would show an improvement.

Looks like an NForce2 board, so he should be able to run at PC3200 unless he's got a really bad 2500+ which is also locked. Like I said, though, if he actually *uses* over a gig doing what he's doing, it will be useful, but it's a waste otherwise.

Keep in mind that Athlons benefit a lot less from dual channel than Pentium 4s.

Z

The 865/875 chipset performs best when all memory slots are fully populated. In fact, the benchmarks showed that 4 sticks of dual channel overclocked the worst of several options, but actually performed better than all of the higher-clocked options. The 5-8mhz of speed difference of two sticks vs four didn't equal out to the several hundred mb/sec throughput increase that the four sticks picked up.

The problem is, we're talking about moving from dual channel back to single. In order to run DUAL channel, you need to install memory in pairs. By installing a single 1gb DIMM, you're going to hose your memory bandwidth. You're much better off installing a pair of 512's along with your pair of 256's.

Well with two people agreeing that P4s perform best with 4 sticks, I'll declare defeat. I don't know why I thought that. Maybe the article did say it, and the article was just wrong . . . Either way, I've edited my post so that people don't read it and think it's true.

Anyway, I'd say the best bet is to get two 512 PC3200 sticks and use those until you actually need something that requires more than a gig of RAM (which you said isn't all that often), and then suffer the bandwidth hit of going from PC3200 to PC2100 and gain the use of 2GB of RAM.

Also, if your PC2100 is CAS2, you might be able to compromise and raise the CAS enough to run PC2700 speeds and use both at the same time. At PC2100 speeds, you're underclocking your 2500+ anyway (see my edited first post).

Z

um 2x512mb sorry ... a brainfart

I've been running async, so the cpu is at full speed.

I do indeed intend to use over 2gb but not always since I use this machine for a variety of things. When rendering animation, ram can make a huge difference in quality//detail in the scene. Ram limits detail by making it impractical. All you need is a few seconds that need a swap file and you're dead in the water. I'm not talking about a game loading "faster", I mean going from 5 minutes per frame to ... you do the math. It's a brick wall.

Thanks though, you've all been super helpful.

PS I have 3 slots and I have run them mixed before in dual channel. At the time I had 2x356 (really!) + 1x512 -- not the same brand either

Okay . . . good to know that you've been running full speed. Running in sync at 400MHz will probably provide a performance boost in everything. With 3 slots, I guess running 2GB at the same time for rendering and running 2*512 PC3200 the rest of the time isn't really doable. I guess just do what you think is best.

Z

I got it.

The first stick I got ($104 128xdensity) didn't work at all in any slot, even alone. The system would boot with it installed as long as the other ram was in slot3 (1? the furthest from the cpu) but was not recognised.

The second stick I got ($170 64xdensity) worked the charm; runs dual channel and is recognised. I may mess with timings ... or not. I'd rather have a % increase stability/longevity than the same % speed.

I assume it's just my imagination, but it feels "different" already

Are you running with 2GB at PC2100? If I were you, instead of messing with timings for the sake of messing with timings, I'd loosen up the timings until you reach the max of your PC2100 and see if it helps performance. P4s are less affected by high latencies than AMDs, if I'm not mistaken (again), so you may reach a point of diminishing returns with raising timings and raising FSB. I'd think that PC2700 is doable . . . And probably at okay timings.

Z