Faulty Memory RAMs in Dual Channel but no errors in Single Channel

Hey everyone,

I've got a situation with my old rig I couldn't make sense of.

Asus p7p55d pro
Intel i7 870 2.93Ghz
2 x 2GB OCZ DDR3 1600Mhz CAS 7-7-7 Dual Channel
Nvidia GT 1030

Lately my PC has been unstable and crashed twice over the last 24 hours which never happened in the past.
It happened while I was (legally) downloading large files using Utorrent.

1st crash: PC frozen on a dark screen
2nd crash: frozen screen in Utorrent with red artefacts located in the upper left of the screen.

May or may not be related but 2 days ago while watching a video I've noticed artefacts in the video.

At this point I was thinking my new Nvidia GT1030 was faulty. I ran a 3D OCCT test and it didn't return any error or artefacts on the screen. I also monitored the GPU temp as often artefacts are caused by the GPU overheating but the GPU wouldn't go above 55 degrees Celsius.

I then ran a memtest with by 2 RAMs in and bingo heaps of errors as illustrated below



Then to determine which RAM was faulty I removed 1 DIMM and ran the test. 0 Errors, ok must be the other DIMM which is faulty. I swap the DIMMS and run the test and it returns 0 errors



How do you explain that I get errors when the 2 DIMMS are in but when used in a single channel they are working fine?

Thanks

One of the modules has gone out of spec relative to the other, thus is no longer almost identical to the other one.
The only answer is to buy a new Kit of 2.

It could also be a change in MOBO characteristics on one channel.

Faulty dimm socket or motherboard tracks to that socket. Make sure the faulty socket is clear of dust/particles. Beware of any overclocks on the system too.

Question: did you try one DIMM in each RAM slot?

That'd be to test whether there's a RAM issue, or a problem with the motherboard. (Or the CPU. I'm not sure whether the i7 870 includes the memeory controller, but I'd guess that it does.)

I see that the MB may be more than 10 years old. I wouldn't expect one to fail due to age, but I don't normally keep hardware that long.

Clean the memory and memory slot with a contact cleaner spray.

Megahertz said:

Clean the memory and memory slot with a contact cleaner spray.

NOT with one that contains oil though !, at high frequencies such oils can short out contacts. If you use a solvent spray, it can also cause condensation (water) due to the low temperature so blow over with a hair drier on low heat before reseating the ram and switching on. I'd first try an air duster and small artists brush. The ram contacts could be cleaned with a clean tissue, anything harsh could take off the gold plating.

Testing for fewer than 8 passes has a significant number of false negatives.
A false negative is a displayed test pass when there is malfunctioning RAM.

Use Memtest86+ version 5.01: Memtest86+ - Advanced Memory Diagnostic Tool


Please test in the following fashion:
a) Test each RAM module in the same DIMM for 8 or more passes.
Just 1 error is a test fail.
b) If both RAM modules display test pass for 8 or more passes then test each DIMM with one of the modules for 8 or more passes.

Digitaldreams said:

NOT with one that contains oil though !, at high frequencies such oils can short out contacts. If you use a solvent spray, it can also cause condensation (water) due to the low temperature so blow over with a hair drier on low heat before reseating the ram and switching on. I'd first try an air duster and small artists brush. The ram contacts could be cleaned with a clean tissue, anything harsh could take off the gold plating.

Sprayway Sea Care QE Contact Cleaner - 13.5oz - Newegg.com

Helmut said:

One of the modules has gone out of spec relative to the other, thus is no longer almost identical to the other one.
The only answer is to buy a new Kit of 2.

It could also be a change in MOBO characteristics on one channel.

If one of the modules has gone out of specs that would result in the MB operating in single channel instead of dual channel. That doesn't explain why the errors in dual channel operations? For example you can have 2 different RAM module in your system and not having any issues. The memory channel would just run in single channel.

bobkn said:

Question: did you try one DIMM in each RAM slot?

That'd be to test whether there's a RAM issue, or a problem with the motherboard. (Or the CPU. I'm not sure whether the i7 870 includes the memeory controller, but I'd guess that it does.)

I see that the MB may be more than 10 years old. I wouldn't expect one to fail due to age, but I don't normally keep hardware that long.

I will test that out as soon as my MemTest scan is completed.

Megahertz said:

Clean the memory and memory slot with a contact cleaner spray.

Digitaldreams said:

NOT with one that contains oil though !, at high frequencies such oils can short out contacts. If you use a solvent spray, it can also cause condensation (water) due to the low temperature so blow over with a hair drier on low heat before reseating the ram and switching on. I'd first try an air duster and small artists brush. The ram contacts could be cleaned with a clean tissue, anything harsh could take off the gold plating.

Good idea, it's an old MB and it's dusty and all. A good clean up will only do good.
I've ordered online an air duster can and a contact cleaner can.

Just out of curiosity, I get what does an air duster can, it blows high pressured air to blow away dust and debris in hard to reach areas. But what exactly a contact cleaner does? Is it a liquid?

zbook said:

Testing for fewer than 8 passes has a significant number of false negatives.
A false negative is a displayed test pass when there is malfunctioning RAM.

Use Memtest86+ version 5.01: Memtest86+ - Advanced Memory Diagnostic Tool


Please test in the following fashion:
a) Test each RAM module in the same DIMM for 8 or more passes.
Just 1 error is a test fail.
b) If both RAM modules display test pass for 8 or more passes then test each DIMM with one of the modules for 8 or more passes.

Downloaded and booted MemTest using your link. It still boots up MemTest v4 because my MB has a BIOS. Recent MemTest versions only runs on UEFI systems.

a) Been running memtest for 5h and I've got 9 Passes VS 57 Errors. Yesterday when I tested this exact same memory module it successfully passed the test without errors in 8 mins. I'm confused? Can they be false positives? How long does it take for the test to complete?

Just 1 error is malfunctioning RAM.

For replacement options:
Run: Crucial System Scanner



Test 1 module at a time in the same DIMM for 8 or more passes to differentiate good from malfunctioning RAM.



If you want to make additional tests:

Run Memtest86 version 8.3 (or newer version if available) for four passes.
Repeat the test so that eight passes are performed.

MemTest86 - Official Site of the x86 Memory Testing Tool

Use a camera or smart phone camera to take pictures and post images into the thread.
In case there are any problems uploading images use share links (one drive, drop box, or google drive)

Memtest86 has a feature to produce a text report.
Please post this in addition to the images.