DDR400 should be backwards compatible with ddr266/333 so it is absolutely fine to use it. HOWEVER: I have seen many weird problems trough the years with memory where some DDR modules (sdram as well) simply were not stable nomatter what you tried, while they worked fine in another system.

Switching to another type/brand is usually the simple solution. I have had many systems over the years that simply worked best with Kington valueram modules for example, they were not the fastest and no overclock wonders but very much trouble free and reliable. Voltage difference between 2.5 or 2.6 is not a big problem, your psu might even fluctuate more than that... (check that).

Simply thinking that another system might get the same problems is probably wrong, usually (in my experience) every system is different and certainly so with a different chipset, revision, brand, psu etc. etc.

Just do some trial and error. Memory testing programs do not always show you errors.

The usual checklist for me:

Try different ram, start with only one stick slowest timings first
Try different psu
Try with the least possible cards (no soundcard, no Matrox M3D for a while)
Make sure your cooling is good enough, check under load in trouble games (cool that voodoo3 also, it is hot)
Check the caps on your motherboard and graphics card
Try another harddisk, many bluescreen and dll errors come from a bad disk/reading errors

Good luck!

meljor wrote:

Simply thinking that another system might get the same problems is probably wrong, usually (in my experience) every system is different and certainly so with a different chipset, revision, brand, psu etc. etc.

Well, the reason I think it might have the same issue is because, based on what I've seen already, the prime suspects are the CPU, motherboard, memory, or the video cards. The motherboard and memory will be different, but the CPU is very similar, and I'll be using the same video cards (that's the primary purpose of this system, without them there's no point of having this system at all). Besides the memory, another idea I had was that the PowerVR drivers for some reason don't work well with the P4. I wanted to get a PIII system, but I saw this really cool looking Sony Vaio, and I couldn't resist. I hope it doesn't have the same issue, but we'll see. The Vaio unfortunately lacks the original mount for the HDD, so I'm going to have to find another way to mount the HDD.

I'll probably make a thread about the Vaio some time soon. It's a pretty cool system; it'll be awesome if I can actually get it working the way I want it to.

EDIT: One other thing, if I remember correctly I tried one other memory module in the older PC - I think it was a DDR-266 stick. I had the same issue in Win 98 that I was having with the other memory module, but I can't rule out the possibility that the memory somehow corrupted the system files, and that's why the problem persisted with the other memory. To rule that out, I would have to do a new installation with the different memory.

I would try running memtest86 and see if the ram stick is still good.

chrismeyer6 wrote:

I would try running memtest86 and see if the ram stick is still good.

I tested the memory with at least 2 different tools, I don't remember which ones. They didn't find any problems.

Ok that's good. Did you check the memory settings in the bios make sure that the voltage and timings are set properly?

chrismeyer6 wrote:

Ok that's good. Did you check the memory settings in the bios make sure that the voltage and timings are set properly?

Like I said, the voltage is set with jumpers on the motherboard, and it was set to 2.5V. DDR-400 is supposed to run at 2.6V. I don't know if the .1V difference matters. I didn't check the timings. I think meijor might be right in that maybe the memory and the system don't work well together for some unknown reason, but another memory module would work.

One reason I thought the memory could be what caused the problem is because, in Win Me at least, the problem affects games that use the m3D but not games that use the Voodoo 3 - and that could be explained by the fact that the m3D directly accesses the system memory, whereas the Voodoo 3 uses its own VRAM. It's also possible that the m3D has a problem; I've never been able to get it fully working in such a way that it doesn't ever have any problems, though when I was using Win 98 previously I didn't encounter any problems in games or when I was loading games - which makes it seem like the m3D is actually fine, though I'm not sure.

So, I'm thinking of getting a 512MB DDR-333 module for it.

You shouldn't. Your issues are clearly not located in RAM, if memtest/prime95 don't get any errors for prolonged period of testing.

The Serpent Rider wrote:

You shouldn't. Your issues are clearly not located in RAM, if memtest/prime95 don't get any errors for prolonged period of testing.

Well, this is not supposed to replace the memory in the other PC, it’s for the Vaio. The manual says you should use PC2700, and don’t have any modules like that. It probably doesn’t matter, but it’s pretty cheap anyway, and I think it can’t hurt to have some extra memory.