GA-890xa-UD3 and 2x2gb Corsair crashes consistently in dual channel

[Aries144]

...but runs fine with a single stick of RAM or with the ram sticks in different channel slots (not running dual channel).

I'm running:
Phenom II 965
GA-890xa-UD3
2x Corsair 2gb CMX4GX3M2A1600C9
Stock CPU cooler and pre-applied paste
Palit GeForce GTX 460 1gb
XFX 650w
WD 640GB 6 gb/s SATA
Windows 7 64
Antec 300 (two fans)

This is my first build.

I had issues almost immediately and quickly learned about the trouble the Phenom IIs have with dual-channel memory at 1333. Random crashes, BSOD, etc.

I underclocked to 1066 and left voltage and everything else on auto.

This helped stability, but it would still crash at almost the same point every time when running in dual channel mode and running prime 95 RAM stress test.

I experimented with the timing settings, mainly trying higher settings or copying settings from various internet posts, which didn't seem to have much effect, if any.

I experimented, still at 1066, with upping the voltage to as high as 1.58, with different timing settings (varying from 8 8 8 24 to 7 8 8 19) which seemed to improve stability a little, as it would get just a little further into the prime95 test before seeing an error message saying something like 'rounding error .05 expected less than .04' and then rebooting, freezing, or BSODing.

Finally, with frustration mounting, I read a post where a guy set his memory clock back to 1333, everything else to auto, and moved one stick of RAM to a different slot in order to disable dual channel mode.

In this configuration, my system seems totally stable.

Here are my questions:

Anybody know why can't I run in dual channel mode, even with the memory downclocked to 1066 and the timing settings at auto (or manually at 8 8 8 24), but non dual channel works fine?

Is this a known issue and I simply haven't searched well enough?

The RAM *seems* to be fine- could I have a bad MB?

I realize now this is Intel ram, could this cause a problem like this?

How much performance am I losing without dual channel?

Thanks

 

[hell_storm2004]

Go back to default settings and do a memtest86+ on the RAM's individually.

 

[Aries144]

So far:

Set all bios settings to auto. Did 20 minute tests using prime95 Blend- one 20 min test with each stick of RAM in slot 1. Everything passes.

Put both sticks back in on dual channel in slots 3 and 4 and made the following changes:

Manually set memory clock to 1333 and Upped ram voltage to 1.66 (you were right- ram voltage is supposed to be at 1.65 not the board default 1.52)

Ran Prime95 Blend: Got almost through all of the 1024k length tests when worker#1 failed with a 'rounding 0.498(etc), expected less than 0.4.' The other "workers" continued but I ended the test.

I restarted and went back into BIOS and made these settings:

memory clock: x6.66 (1333mhz)
DRAM voltage control: 1.66
NB voltage control: 1.170 (from 1.150)

Testing for 1 hour with Prime95, Blend test, results in no errors!

I think this might have gotten it!

Any other suggestions?

Thanks again for the help!

 

[Aries144]

OK, I'll try the tighter timings.

Yeah, that's what the selection says anyway- 'tests more ram' is how I believe it reads.

Worker 1 may be core 1, but I don't really know if each 'worker' corresponds to a specific core, or if it just runs 4 'worker' instances because there are four cores.

From what I've gleaned over the past day (and night), prime95 seems to be a fast checker, while memtest86+ is more thorough and gives more detailed feedback when errors occur.

I used prime95 because it was just a simple program that could be run. I think you have to make a boot disk from an .iso and boot with memtest86+, don't you?

I'll probably give memtest68+ a go overnight, just to be sure.

 

[Aries144]

Best answer selected by Aries144.