From 80000 memtest errors to zero in 2 hours unplugged

[BadOmen]

Greetings, all. Long story short: computer was fine. Then I plugged a second monitor in the second slot of the video card. Turned it on, and got a blue screen.

Tried to run Windows Repair, it failed to initialize Windows.
Run Memtest, and got 80,000 errors in 5 minutes
BUT Asus' own OS, the little Express Gate, worked perfectly.

Now I have removed the second monitor, and after letting the computer rest for 2 hours unplugged, I ran Memtest again and there's absolutely no errors.

What on the deepest pits of hell can that be? I noticed some people complaining about Asus motherboards and hardware changes, but due to Memtest results, I thought I should post it here. If you think I should take it to some other forums, just let me know. And any tips are greatly appreciated.

thanks a lot

 

[sub.mesa]

Power issues? Does your motherboard have an extra power connector around the PCI-express ports?

Your memtest should yield 0 errors on 24 hours of testing; anything different means unstable system. This can be caused by:
- overclocking
- heat build-up in RAM, CPU or chipset
- unstable power supply
- bad memory ;-)

Sometimes the errors would only come after a few hours; in this case it can be temperature related. Do a torture CPU test such as with Prime95, to test if your CPU can run stable at maximum load. Is your temperature under 50 degrees while stressing your CPU? If not you may want to start with reducing the heat.

 

[BadOmen]

Thanks for your answer. Temps are usually excellent, cpu idles at less than 30, gets around 40 on stress. I haven't tested it with Prime95, though. Just regular use.

The computer runs under BIOS defaults, so unless the BIOS comes with some natural overclocking, there's none. I actually reduced the memory voltage when I assembled the rig, as this G.Skill Eco is supposed to run at 1.35V. BIOS default was 1.5, I use 1.4.

The motherboard doesn't have extra power connectors other than the two regular ones. The video card has one, and it's plugged.

The Memtest failure came along with blue screens, internet browsers crashing (in the few minutes before a blue screen), and even an "overclock failed" message from BIOS when restarting the computer after a blue screen. All that disappeared after a few hours of "rest", and I'm writing from that computer right now. That makes me think if this is really memory related or if something else was compromising Memtest's results.

Anyway, I'll run memtest through the night and see what it tells me tomorrow.

 

[Rubycon]

Could be interference. Make sure both monitors/power packs (if equipped) are on the same circuit and their grounds are at the same potential.

If there is potential on the connectors of the second monitor this can cause oscillation that causes the PLL on your system board to go awry. These things explain why perfectly functioning (otherwise) hardware gets into serious trouble when another peripheral is connected.

 

[FishAk]

The video card has one (connector), and it's plugged.

I assume that, by this you mean to say that its plugged in to power, but instead, are you saying it just has a blank plug in it?

If so, that could explain why adding a second monitor would cause the board to go haywire- due to starving for power. If it has a blank plug, all the power for the card must come from the board. I don't think that's what you mean, but there is a chance...

 

[BadOmen]

I didn't even leave Memtest running last night. It got to thousands of errors in a matter of seconds, so I turned the computer off.

HOWEVER, I ran it again in the morning and it passed flawlessly.

Could be interference. Make sure both monitors/power packs (if equipped) are on the same circuit and their grounds are at the same potential.

I don't know if I got that right, possibly not, but I have everything plugged to an APC. My main monitor is on the Battery Backup outlet, but the secondary one is just on the Power Surge. No battery backup. Does that mean that they're on different circuits? Plus, the main monitor plugs straight on the APC outlet, while the secondary plugs on an AC Adapter first.

I assume that, by this you mean to say that its plugged in to power, but instead, are you saying it just has a blank plug in it?

No, it's not blank. I have a pci-e plug from the power supply plugged there. I think this card wouldn't work even with just one monitor without being plugged to the PSU.

 

[Rubycon]

They are probably on the same circuit. The important thing is grounding and making sure that ground is common amongst all devices. Differences will result in voltages that can cause a plethora of problems.

 

[Zap]

I don't have any ideas for you, but do have a story of my own that happened about two weeks ago. New build for my in-laws and I decided to run Memtest since the RAM was used. The system was on an open test bench. First pass was all good with no errors. I left it running while I went to do something else. Came back and there were two errors. Hmmm. Decided to give it another loop just in case, and then there were dozens of errors. WTF? Went to lower RAM speed and relax latencies, ran Memtest again and it gave errors immediately and continuously. WTF?

I shut off the system to swap out the ram, and it was burning hot! Turns out that since it was on an open test bench and had no forced air plus was running a stress test, it overheated.

I leaned an 80mm fan against the RAM and ran the system, letting it sit in BIOS for a while to cool the RAM. Then, ran Memtest (at full speed/latency) several passes with no problems.