DDR400 RAM at DDR200 after 2GB to 4GB upgrade?

I’ll need to explain some detail before I ask the question that’s in the subject line. Some background on my system: I have an Asus A8N-SLi Premium mobo (socket 939) with an Athlon 64 x2 4400+. Up until last week, I had 2 GB (2x1024) of OCZ DDR400 Platinum (PC3200) running in Dual-channel mode. I noticed a decent sale on almost the same RAM (the tCL is 2.0 vs 2.5; all other timings are the same according to the SPD for the modules) and ordered another 2 GB to up my system to 4GB. I have Vista Ultimate 64-bit, so it was no problem with accessing it or anything. So, I put it in and everything worked smoothly, Vista proceeded to use as much of it as it could (seems about twice as much as it used to, which is normal, I’ve been told), and I thought that perhaps I should run the simple Windows Experience Index to see if it changed it at all. My RAM score used to be 5.0.

Well, after the first run my RAM score had dropped to 4.0. I thought that odd so I ran it again and it came out 4.2. Figuring it strange that adding RAM would reduce the score, I did some research and discovered that this may be normal because using four slots is actually slower than using two slots. Okay. I rebooted my system to visit the BIOS and see what settings were available to perhaps up my RAM speed a bit and I noticed that it was displaying my 4GB as DDR 200 as it POSTed! Hmm, perhaps the BIOS defaulted to that and all I need to do was up it back to DDR400. Oh, I found the setting and did that. Big mistake!

Now I couldn’t boot at all. Black screen. Nothing. Had to reset the BIOS manually using the jumper on the board. Oookay. Guess that was wrong. So I did more research. Turns out that it was normal for people to have their system downgrade to DDR333 when you have four slots used, but only once could I find someone who had theirs go to DDR200. The advice was to relax the timings and up the voltage. I put the voltage from 2.5 to 2.6. That was straight forward enough (2.6 is the limit for the lifetime warranty on rev1 of this RAM type). I noticed the BIOS had automatically set the timings as 2.5/3/3/5 (the SPD is 2/3/2/5 or 2.5/3/2/5 depending on the module pair). I upped the tRAS from 5 to 8, on the advice of one of the forum posts I found on Asus forums, exited the BIOS, but it had no effect, even if I turned off the Cool’n’Quiet function.

I’m thinking I may have to alter something else, but I’m not really wanting to manually reset the BIOS each time by setting these things wrong. I wouldn’t mind getting at least DDR333 out of it, but DDR 200 seems rather low.

My questions are these. First, do I even need to be concerned about the DDR200? Should I just let it be? I would think that halving the speed of the RAM would be a big issue, and WEI seems to think so, at least. Second, if I want to fix this, what should I look to changing in the BIOS? I don’t want to overclock anything else; I only want the RAM back to some semblance of normal.

Y’all seem to have decent advice on tech, which is why I posted it here. This was an unexpected occurrence, as I’ve never heard anyone say anything about watching out what happens to the speed of your RAM when you upgrade. It was always “more RAM = good”. Not bothered by it so much as interested in if there’s a fix. Live and learn and all that.

[Edit] Wanted to let any readers know that I decided I better, at least, post this at the OCZ forum to see what the makers have to say on it.

You could run some general-purpose benchmarks to see if the RAM speed makes a big difference, but it probably doesn’t.

Yeah, it’s a pain in the ass that RAM advertising is so dishonest. All the performance and compatibility claims only apply to 1-2 installed modules. Put in more than that, and you’re on your own.

Usually you need to relax the timings and up the voltage to run four modules, just as you said. No idea why that didn’t work for you, it worked for me! :p (but on a different motherboard with a different RAM manufacturer)

Does the manufacturer’s website have any recommended voltage setting for DDR400 operation? I used that for 4-module operation – it’s quite a bit higher than the motherboard default.

I did get a quick response from an OCZ rep. He suggested putting the voltage at 2.7V (which is beyond the lifetime warranty limit of 2.6V according to their site) and relaxing the timings as far as they can go and setting the mem speed to DDR333. What I didn’t do in my test was set the mem speed, because I figured that was done automatically by the system (and setting to DDR400 had very negative effects the first time I did it). He said it was par for the course to have to reset the BIOS when doing this sort of testing. Guess I’ll have to suck it up and do it (after he confirms the voltage requirements).

Couldn’t go all smoothly, though. After the last reset I also started getting static from my speakers at times. Figured it was an IRQ conflict and moved the X-Fi this morning to a new slot. Was worse than ever after it was up again. Ugh. Turns out it was sharing an IRQ with my Marvell Yukon Gigabit LAN (my board has dual-gigabit ethernet). So I disabled that in the BIOS to (so far) fix that problem (it was always disabled before, I just forgot to re-disable it after the BIOS-clear).

Meh, thought I’d update the thread (in case it’s ever read again by someone who cares). On the advice of the rep, I upped various voltages, relaxed some timings, and got the RAM to run at DDR333 (actually, it’s more like DDR315 or so), but it’s an improvement, and memtest86+ shows it as error-free. Might play around with some additional tweaking to see what else I can do now that I got it to a point I’m okay with.

So, it’s doable. I’ll be upgrading in the next 12 months to a new mobo/CPU/RAM combo anyway, so this is just a mini-step along the way. Now I know more about RAM and its quirks.