Bad RAM or MOBO?

[petefbi]

Hi...

I just upgraded my mobo and memory to;

GIGABYTE GA-990FXA-UD3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128514

and;
CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin SDRAM DDR3 1600
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145345

And I think I have a problem with one of the sticks. Never had a problem in the 10 or so memory upgrades I've done before so wanted to check I've narrowed things down correctly.

My CPU is;
AMD Phenom II X4 970 Black Edition Deneb 3.5GHz
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103894

All was well with the install (minor BIOS tweaks needed to get the memory running at spec) after I set it up with just 1 of the RAM sticks ("A") in slot 1.
After running Prime on and off, to bed in the CPU, and a run of Memtest I put the 2nd stick ("B") in slot 3.
It booted up fine but then took errors in Prime and it stopped running on one of the cores.

Took "B" out and it ran fine again.
Bad memory for sure...?
I put "B" in slot 1, by itself, and Memtest showed it all clear!
So, worrying it's now a bad slot on the motherboard I did the following tests;

1) RAM "A" - Slot 1 - Passed
2) RAM "A" - Slot 2 - Passed
3) RAM "A" - Slot 3 - Passed
4) RAM "A" - Slot 4 - Passed

5) RAM "B" - Slot 1 - Passed!
6) RAM "B" - Slot 2 - 5 Errors
7) RAM "B" - Slot 3 - 5 Errors
8) RAM "B" - Slot 4 - 82 Errors

So... a little confused as RAM "B" works in Slot 1 yet fails in all the others (in varying degrees).

Should I be worried about the Motherboard or does this look like a textbook "bad stick"?

Motherboard is Rev 1.0 with F4 bios.
No other visible system issues - I really am still at the beginning of checking everything.


Thanks in advance for any help!

Pete

 

[beenthere]

Sounds likes a RAM issue to me since DIMM A works fine in all the slots and B only works in slot # 1. I'd RMA the RAM / contact Corsair Tech Support.

 

[petefbi]

Thanks for your input ... Newegg are sending me replacement memory and I can keep the old stuff until it gets here.

 

[petefbi]

Best answer selected by petefbi.