New memory won't run at rated speeds - FIXED

[CurseTheSky]

So, this is my second set of the memory. With the first set, I was getting BSOD's randomly: sometimes with both sticks, sometimes with one, sometimes at DDR2 800 5-5-5-18, and always at DDR2 1000 5-5-5-12. To top things off, the notch on one of the sticks was slightly off, making it nearly impossible to get in the memory slot.

The kit is the Mushkin 996593 (2x2GB, DDR2 1000, 5-5-5-12 @ 2.1V). I've been running a set of Corsair Dominator DDR2 800, 4-4-4-12 rock solid for over a year. I have the new kit stable at DDR2 800, 5-5-5-15 right now, but it's no where near what I want it to be clocked at.

Before I start blaming the memory, I want to make sure I have everything set where it should be. I've added +.01 volts to the SPP, MCP, SPP->MCP bus, etc. The memory is at 2.1V, and there's no overclock on the processor. Where should I start to figure out where the stability issue is?

Thanks.

 

[GarfieldtheCat]

Have you run memtest yet? It should show errors if the memory is bad.

Perhaps a BIOS setting that you set for the Corsair RAM that the new RAM doesn't like? Can you put all your memory BIOS settings to auto to see if you still get errors running memtest?

 

[CurseTheSky]

I reset all the BIOS to defaults when I installed the new memory. I've also manually cleared it (jumper) since then as well. I'm using BIOS P32 (latest) and have the latest Vista x64 chipset drivers installed (15.08).

Taking a quick peak in CPU-Z, it's listing the part number as "991593 (996593);" not sure if that means anything. The max bandwidth is also listed as "PC2-6400 (400MHz)," but it does have EPP set at 500MHz 5-5-5-12 2T, 2.050V. The max bandwidth kind of caught me off guard... is that just because of the JEDEC standard?

Edit: as far as the two part numbers, it seems that's just the part numbers for the single 2GB module, and the 2x2GB kit. That makes sense. http://www.mushkin.com/doc/pro...mory_detail.asp?id=647

 

[n7]

There are a number of things that can affect stability with 2 GB dimms.

One big thing is TRFC.
That's one of the very important subtimings.

I don't know what your motherboard defaults that kit to, but you're going to want to check that.
I assume you know how to set your primary timings to 5-5-5-*

You're going to want to look for TRFC & set that to at least 50+ (higher is easier on the RAM, & will barely affect performance at all).
Anything much lower & you won't even be able to run that kit @ its default speeds.

Now to help with monitoring timings, etc., get MemSet: http://www.xtremesystems.org/f...showthread.php?t=92190

It will tell you what the primary timings are (which CPU-Z can do anyway), but more crucially, it reports the TRFC & other important subtimings like TRD (called "Performance Level" in MemSet).

Depending on how tightly your other subtimings are being set, they may need to be adjusted looser slightly as well, though not too likely.

I don't know nF680i bioses well, so there may be ratios or modes (linked vs. unlinked) that are easier to work with; that i cannot help with.

I would suggest also posting on Mushkin's very helpful forums if you cannot get things going, or want some more input
http://www.xtremesystems.org/f...showthread.php?t=92190

Greg or someone else there will quickly be able to fill you in on what voltages, timings, subtimings, etc. you need to try if you post a thread with all your system specs there

 

[n7]

If it helps, here's a screenie of my settings i was running for my 8 GB Mushkin.

It's the DDR2-800 4-4-4 kit, but in actuality, it's very similar to the one you have.

Mine's DDR2-800 4-4-4 2.1v
Yours is DDR2-1000 5-5-5 2.1v

Both kits will overclock to very similar speeds.

Check out the MemSet portion of this screenie specifically...your kit should be able to run with the same settings at DDR2-1000 at least, though performance level might be higher.
http://img139.imageshack.us/im...hz14vcore145vnbnz5.jpg

 

[nerp]

Aren't the 680s REALLY picky with memory?

 

[n7]

Originally posted by: nerp
Aren't the 680s REALLY picky with memory?

AFAIK, yes.

So he likely has his work cut out for him...hence the recommendation to post on Mushkin's forums.

They are awesome for posting all the timings & settings needed for all the different mobos

 

[nerp]

Yeah, I'd get in contact with Mushkin and ask for every last bios setting. I've seen other posters here comment that once they got the 'ideal' settings from the manufacturer, things were fine.

 

[CurseTheSky]

Wow, I don't know why I didn't think of the subtimings. Probably because I've never touched them before (never needed to).

Basically I had the subtimings set to the BIOS defaults. In the 680i BIOS, there are two memory options - Optimal (auto) and Expert (manual). When you load the system defaults, the memory is set to Optimal, but it pulls the timings from the motherboard rather than the memory. The original primary timings were 5-5-5-18 2T, which I quickly set to 5-5-5-12 and ran into problems. Just by chance, I went in and set it to Optimal a second time. This time, the primary timings were automatically set to 5-7-7-24 2T, and the subtimings (tRC, tRFC, tWR, etc.) were completely different. Again, I manually set them to 5-5-5-12, except this time it BOOTED!

So, it's definately the subtimings. Whatever BIOS loaded as the original defaults just weren't working out; pulling the defaults from the memory itself did the trick. I wish I had thought to do this originally. I still won't pretend to even begin to know what the subtimings are all about... I only have a basic grasp of the primary timings, lol.

Thanks guys.

 

[n7]

Glad to hear.
It's most likely TRFC.

I wish manufacturers would label the importance of this subtiming in the documentation somewhere, as with basically any DDR2-1000/1066 2x2 GB kit, you will NOT be able to run the kit at default speeds without that being set appropriately.

If you could post a screenie of MemSet, it'd be interesting to see what they're set at.