New build, Memtest errors, help please :(

[veras]

I put together a new box this week and I've been having errors (CRCs on installs, stuff like that) in Vista so I went and ran Memtest86+ and I'm getting errors.

Relevant hardware is Q9550, Asus P5Q-E, 4x2gb Corsair PC8500 RAM

Tested all the RAM at once (errors), updated the BIOS (no change), I've tested each stick individually in Memtest (each one gave errors), I've tested a stick from my previous computer that I'm 99% sure is good (gave errors), I've tried RAM that failed in slot 1 on different slots on the motherboard (all gave errors)

Is there anything else I can try? Is the motherboard a dud? Could it be another piece of hardware? BIOS settings?

Thanks for any help, this is driving me nuts

 

[Uncle Bob]

Having one bad stick is possible but getting a bad pair is unusual and unlikely - unless you've accidently damaged them with a static charge.

Are you able to test the Corsair ram in your old pc?

 

[veras]

Sorry, to be clear that's four sticks of 2 gb RAM - I figured the odds of all four being bad was astronomically low. I am going to test them in another box when I get the opportunity just to be sure, but I'm figuring it's probably a motherboard or CPU problem and was wondering if there was any way to determine which if that was the case, or if I just RMA both or what. (or if it could be BIOS settings)

Since posting I've also made sure the RAM was getting enough voltage by turning it off auto and setting it to the RAM's recommended spec, but that didn't help either (still errors)

 

[Uncle Bob]

Right, 4 sticks - didn't notice that, but you're right the odds that all 4 are bad are astronomical.

If you have another pc which you can use to test them, then maybe you could also swap CPU's to test this also? But if the RAM tests good in another rig, my money would be on the motherboard being bad.

 

[veras]

Okay, I tested the new RAM in an old, known good box and all four sticks came out clean - 0 errors.

Where do I go from here? RMA the board and/or CPU? Could it be a BIOS thing still?

Thanks

 

[mpilchfamily]

4 DIMMs puts allot of exstra strain on the motherboard. Offten you have to go into the bios and pump the RAM voltage up a bit. Chances are the DIMMs just aren't getting enough power.

 

[veras]

When I was testing the DIMMs individually, I was booting with just one DIMM in the system and getting errors. I replaced the P5Q-E with a P5Q Deluxe this morning, and I am still getting errors. How do I proceed from here? Is it a CPU issue? Is it BIOS settings? (everything is on defaults/auto right now, but I've tried setting the memory voltage manually to spec)

 

[piaf]

I just built a very similar system but with 2 sticks of ram,
Q9550, Asus P5Q-E, RAM is the Corsair TWIN2X4096-8500C5DF.

I experienced random crashes, Bad CRCs, etc.
I did not do a full run of memtest86+, But there were no errors for the time I ran it,
And it passed the vista memory test.
However, I ran Prime95 and within seconds 2(sometimes more) of the threads would fail with a rounding error.

After I bumped the FSB to 355 with the ram at a 2:3 ratio(1068MHz in BIOS I believe) its running stable with everything so far.
And I do have the memory voltage manually set at 2.10v.

While I'd hate to have to RMA, If this could be a hardware issue that could give me problems later on then I have no choice.

But I'd be interested in knowing if you're still experiencing the same issue if you feel like OCing it a little bit.

 

[veras]

Interesting, could you post specifically what BIOS settings you've tweaked? I intended to overclock anyway so I will definitely give it a try!

That's the exact RAM I bought too, and the exact errors I was experiencing

 

[veras]

Small update, I tried a small OC of 355 and that FSB timing with 2.1 volt ram (left rest on defaults) and I still errored out on Memtest

 

[piaf]

I played with a lot of the bios settings while trying to figure out a cause,
But in the end I have just the following settings changed:
Ai Overclock Tuner: Manual
CPU Ratio: 8.5
FSB Frequency: 355
PCIE Frequency: 100(default)
DRAM Frequency: DDR2-1068MHz

DRAM Timing Control: Manual
tCL: 5
tRCD: 5
tRP: 5
tRAS: 15

CPU Voltage: 1.25000
DRAM Voltage: 2.10
CPU Margin Enhancement: Optimized(default?)

Everything else should be auto/default as far as I can tell.

Also, I do have Legacy USB disabled, And if I remember correctly,
There used to be issues with that and memtest,
So you might want to give that a try.

 

[RadiclDreamer]

Try bumping the voltages and playing with your timings

 

[veras]

Problem resolved! Legacy USB was the culprit!

Thanks very much to everyone who offered advice, and double thanks to piaf for registering and posting the solution - extremely appreciated, big weight off my shoulders!

 

[piaf]

I'm glad I could help.

A few questions though,
Are the errors you were getting in windows fixed?
If so, Did you have to OC to get it stable or is it stable at stock speeds?

I'm wondering if this is just a specific issue with this hardware combo that can hopefully be fixed with a bios update.

 

[veras]

Everything in the BIOS is default except ahci is turned on, the RAM voltage is manually set to 2.1 volts, and legacy USB is disabled (and expressgate is disabled). It did fix my problems in windows, though I'm sorting through some new issues now.

Namely, Firefox is crashing and Prime95 is failing, and 3dmark is locking up occasionally - other stuff is running fine though, and no more CRC issues. I'm going to try manually setting cpu voltage and some other stuff and see what happens.