Mem tests failing - CPU Faulty?

[qbie]

Hey guys,

Ok, let's post this in the right forum this time!

Over the last few weeks I've been experiencing very sporadic crashing with my PC - and it came to a stage last week where I couldn't play Bioshock for 30 seconds without the PC locking up, so I started to look into it.

I replaced my PSU anyway with a Zalman 500W as it was quieter than my old one, so that eliminates that. Also my gfx card has been replaced (just because I wanted to upgrade from my 7600GT, bought an X1950XTX from a friend. The lockups pre-date this though.).

I ran memory diags (MS Memory Diag and Memtest86) and the tests failed or locked up at random points (4x512mb PC3200 GeiL matched pairs). So I played around a bit and this is what happens.

All sticks tested independantly - Pass
Memory in slots 1+2 (Dual Channel) - Pass
Memory in slots 3+4 (Dual Channel) - Pass
Memory in slots 1+2+3 (Single Channel) - Fail
Memory in all slots - Fail

Basically, with more than two sticks of memory in (or if the CPU is trying to address more than one bank?) it fails/locks up the diags, and crashes repeatedly. So, I replaced my Mobo. Old mobo was a DFI CFX3200 (ATI Chipset), new is a Foxconn NF4SK8AA-8EKRS (nForce 4), but the same is happening.

I've borrowed some OCZ RAM off a friend and the same happens. I have an Athlon X2 4400+ so I'm thinking it must be that, as the memory controller may be faulty. I am currently running with only 2 sticks of RAM in slots 1+2 and have been playing bioshock for the last 2 days with no issues whatsoever, and no crashes.

Does anyone have any other ideas? Or do I seem to be on the right track? Has anyone come across an Athlon 64 with a faulty memory controller before?

Based on what someone has asked, everything is running at stock speeds. As for Temperatures , my CPU runs at between 35-45C depending on load, my ambient case temperature is ~40C.

Cheers,
qbie

[Agent]

What moderboard?
Latest BIOS?
Have you set the RAM timings manually in the BIOS? (set them to 'manual' and not auto or SPD)
Up the voltage to the RAM a bit?
Overclocked at all?
Do you get the issue if you _under_ clock?

Just a few things that'll help nail it down to one thing or another

[GSte]

Didn't a lot of nf4 boards have issues with using all 4 ram slots, or was it just that they wouldn't OC when four were used......?

[qbie]

What moderboard?
Latest BIOS?
Have you set the RAM timings manually in the BIOS? (set them to 'manual' and not auto or SPD)
Up the voltage to the RAM a bit?
Overclocked at all?
Do you get the issue if you _under_ clock?

Just a few things that'll help nail it down to one thing or another

Foxconn NF4SK8AA-8EKRS
Yes
Tried Both Auto and Manually Setting
Yes gone up to 2.8
Nope
Yes

Didn't a lot of nf4 boards have issues with using all 4 ram slots, or was it just that they wouldn't OC when four were used......?

It happens with 3 sticks in too though.

[this_is_gav]

Make sure you aren't using 1T command mode. It won't like it if you're using more than 4 slots.

[qbie]

Make sure you aren't using 1T command mode. It won't like it if you're using more than 4 slots.

It's 2.5T as thats what the RAM is rated at.

[kalniel]

2.5T doesn't exist. Command rate is either 1T or 2T. 939 generation memory controllers can't run 4 banks at 1T so you have to drop to 2T.

[qbie]

2.5T doesn't exist. Command rate is either 1T or 2T. 939 generation memory controllers can't run 4 banks at 1T so you have to drop to 2T.

Yes sorry 2T, My mind was somewhere else! 2.5 is CL.

[behappier]

Had that problem before on an Opteron system (identical memeory controller on board to the Athlon 64). Turned out to be a dead CPU. Replaced under warranty after a LOT of discussions with Scan) and it has been fine ever since. So I assume because it has been sold.

[qbie]

Had that problem before on an Opteron system (identical memeory controller on board to the Athlon 64). Turned out to be a dead CPU. Replaced under warranty after a LOT of discussions with Scan) and it has been fine ever since. So I assume because it has been sold.

Well, to fix the issue I've just ordered a 2GB matched pair of OCZ ram from eBuyer. I know it's not fixing the problem, just working around it, but I've had enough messing around with this now so if I put 2x1GB in and sell off all my old RAM and a few bits and pieces I'll be ok.

I'll be happy just to have everything working again.

q