Dual-Channel vs Single troubles

[sadffffff]

Just built a cheapie system since i havent had a new build since my amd 2600+ waaay back, and I didnt want to spend much till im out of college. I'm having trouble with the memory in dual-channel mode. Trying to install an OS resulted in multiple failures and crashes. Ran memtest86 and whenever the motherboard is operating the memory in dual-channel mode, the test stops/locks up or restarts the computer. In single-channel mode the tests run fine. I'm not overclocking the memory afaik and everything is default. Whats up?

Specs ended up being AMD phenom II 720, Asrock A780GXH mobo, 4x 2gb ddr667 (identicle) 1.8v, ASUS 512mb radeon 4850, old hard drives and optical drives etc...

tried bumping the memory voltage to 1.85v and 1.9v, but im not sure how far is safe. Also tried my roommates memory (ddr800) in dual-channel mode and it works fine. Ideas? Thanks

 

[TemjinGold]

Is your roommate's ram also 4 sticks? Does your ram work fine in dual channel when you only use 2 of the sticks? The added bandwidth requirements of dual channel coupled with the fact that you are populating all 4 slots is probably overloading your memory controller.

 

[sadffffff]

Originally posted by: TemjinGold
Is your roommate's ram also 4 sticks? Does your ram work fine in dual channel when you only use 2 of the sticks? The added bandwidth requirements of dual channel coupled with the fact that you are populating all 4 slots is probably overloading your memory controller.

i have tried with just two of mine in either of the paired slots, exact same issues. with my roommate's ram, i tried both 2 sticks and 4, both worked great (and it was 800 vs 667). im at a loss, i coudl try higer voltages, or different timings (though, i'd need help with that, too. i never learned how the different timing numbers jive).

 

[sadffffff]

also, is there a way to disable dual-channel mode if it comes to it? will I lose a lot of performance if i can do this?

I figured running dual-channel would be good since the memory i have is only ddr667.

 

[TemjinGold]

If your roommate's works with 2 or 4 sticks, then it's your ram that's the problem. What brand is it? The best solution if you just bought it is to return it and get the type of ram your roommate has.

 

[taltamir]

it is not uncommon for there to be bios bugs in regards to filling ALL ram slots... actually anand complained about it in their last roundup, how all the boards pushed the envelope on overclocking, but only one worked properly with all ram slot filled, and when he asked the companies they said "but, did you see how high it overclocks?".

I would contact ASrock about this, see what they have to say.

 

[sadffffff]

hmm now things are more interesting (read frustrating). I tried memtest on my roommates computer, same thing. just locks up. then i ran the old version included on the memtest cd. its been running flawlessly for over an hour now.

is this a known thing with memtest86?

I guess i'll try installing vista instead of windows 7, maybe windows 7 was the problem all along.

 

[taltamir]

i dont entirely understand what you are saying... do you have a new non cd version of memtest that locks up?

get this: http://www.memtest.org/