Weird problem that I *think* is bad RAM, but hard to tell so far, help?

[pdegan2814]

Lately I've been having some weird problems with one of my machines at home. The core specs are:

Gigabyte Z68MX-UD2H-B3

intel Core i3-2100(not overclocked, using the on-die VGA)

16GB(4x4)GB Corsair Vengeance DDR3-1600, not sure of exact model, pretty sure it's CMZ16GX3M4A1600C9B

 

I started getting some intermittent errors in a problem which the author says *could* be symptomatic of bad memory, but I also knew the hard drive in that machine had seen a LOT of use. The machine would also lock up from time to time. Then more recently(the last few days), the system began responding VERY slowly. Like, I would right-click on My Computer and it would take nearly 10 seconds for the menu to pop up, and other forms of sluggishness. Eventually I decided to replace the system drive and just reinstall Windows 7, start fresh. On that machine it's pretty easy to do, there's only a few programs running on it. But I seem to be having the same issues. The Windows re-install went SLOOOOOW, and the inevitable download of 300MB worth of updates as soon as the install finished took FOREVER, the installation of those updates took even longer. I STILL haven't been able to get Service Pack 1 to finish installing successfully. And this was after installing the various drivers for the motherboard devices. I began to think it might be the memory after all. I'd tried running it using the XMP at 1600MHz, and at 1333MHz, same result. So I burned Memtest86 to a disc and ran it with all four sticks in. ERRORS GALORE, like hundreds of them(sorry, I'm writing this from work and don't have the output in front of me to refer to). So, time for process of elimination. I tried each stick by itself in slot 1, ran a full pass until Memtest said it was clean and I could stop(I know many say to run it for a lot longer, but I just didn't have the time). All 4 sticks ran with no errors. So I tried the last stick in each of the other memory slots, and slots 2 & 3 also came back clean. The test on slot 4 was still running when I had to leave for work. Assuming it comes back clean, my next test will be a pair of sticks, set up for dual-channel mode, giving the machine 8GB to work from, and let that test run for several hours. If it turns out that machine just isn't stable with all four memory slots filled, it can get by alright with 8GB instead of 16GB. I may pick up a 2x8GB pack at some point for it.

 

Few questions:

 

*could it be that all four sticks are good, but the board just isn't stable with all four slots filled?

*would nudging the memory voltage up a bit help with stability? It's currently running the default 1.5v, should I try going higher, like 1.65v?

*Is there another likely cause for this type of behavior that I'm just missing?

 

Thanks for ANY help you guys can provide

[peanutz94]

*could it be that all four sticks are good, but the board just isn't stable with all four slots filled?

Absolutly. However if they have been running fine for sometime and just ow started this, then something's not right somewhere. But with memtest coming up clean when the sticks are run by themselves it really points towards the memory being okay.

 

*would nudging the memory voltage up a bit help with stability? It's currently running the default 1.5v, should I try going higher, like 1.65v?

Highly unlikely but if you want to give them a little more for testing purposes then just don't go any higher than 1.6v with that CPU. Start out with 1.55v and you may also have to add a little bit to the system agent(memory controller) voltage. But here again since the machine was running stable and the problems have just recently started then it's not going to be a voltage setting...at least i wouldn't think it to be.

 

*Is there another likely cause for this type of behavior that I'm just missing?

Bad hard drive? MB? would be my first two guesses. Maybe try another hard drive, and you can always RMA the memory if you want. I'm just not convinced it's memory your having trouble with.

[pdegan2814]

Well as I said, I swapped out the hard drive right before doing the Win7 reinstall, and I'm still having these problems. Plus, the Memtest isn't touching the hard drive, so I can't see how it could be contributing to Memtest errors when all four RAM slots are filled.

 

It basically feels like the board is having trouble driving 4 memory sticks, while it can handle 1 stick at a time with no trouble(based on my admittedly limited Memtest runs so far). Whether it's the power supply having trouble supplying clean current or the motherboard, I don't know. I've had wonky power supplies cause ALL KINDS of weird problems. I do have a Corsair AX760 waiting for me that I'd already ordered for this machine, to replace the existing PSU(been planned since before these problems, I love the AX line). I'm going to try tweaking the voltage of the memory and the controller. I'm also going to try running with a pair of sticks instead of all 4, see how it goes. I swear, I don't know why I ever bother trying to run with 4 memory sticks, I always wind up with headaches eventually. :)

[pdegan2814]

Ok, looks like I probably have a bad DIMM after all, and I think I've narrowed it down to two. Here's what I've done since the morning. I ran through one pass of Memtest86 v4.1 with each DIMM in slot 1, and with the last DIMM in all four slots, which is what led me to believe that the problem wasn't a specific DIMM or a specific memory slot. With this board, if you want dual-channel operation, you put a pair of DIMMs in either slots 1 and 3(the white ones) or slots 2 and 4(the blue ones). I rant Memtest with a pair in the blue slots, no errors. I ran the other pair of DIMMs in the white slots, ERRORS GALORE. So I took that pair out, and tried the pair that had tested fine in the blue slots, only this time in the white slots, they appear to be testing fine. So am I wrong in guessing that either one of that other pair is bad and the problem only shows itself when it works in a pair, or that pair is just matched poorly for some reason? Either way, I'm gonna let this pair run Memtest for a while in the white slots, since the manual recommends using the white slots if you only use 2 DIMMs, and if I don't get any errors, I'll just resume normal operations only with 8GB instead of 16GB. I can live with that. :)

[RAM GUY]

Ok, looks like I probably have a bad DIMM after all, and I think I've narrowed it down to two. Here's what I've done since the morning. I ran through one pass of Memtest86 v4.1 with each DIMM in slot 1, and with the last DIMM in all four slots, which is what led me to believe that the problem wasn't a specific DIMM or a specific memory slot. With this board, if you want dual-channel operation, you put a pair of DIMMs in either slots 1 and 3(the white ones) or slots 2 and 4(the blue ones). I rant Memtest with a pair in the blue slots, no errors. I ran the other pair of DIMMs in the white slots, ERRORS GALORE. So I took that pair out, and tried the pair that had tested fine in the blue slots, only this time in the white slots, they appear to be testing fine. So am I wrong in guessing that either one of that other pair is bad and the problem only shows itself when it works in a pair, or that pair is just matched poorly for some reason? Either way, I'm gonna let this pair run Memtest for a while in the white slots, since the manual recommends using the white slots if you only use 2 DIMMs, and if I don't get any errors, I'll just resume normal operations only with 8GB instead of 16GB. I can live with that. :)

 

If one pair passes in the DIMM slots but the other pair does not, it would indicate an issue with the memory. I would recommend filling out a RMA so you can exchange your kit with a brand new set from us.