mobo problem - can't run ram in dual channel

[eflat123]

I have a Gigabyte 880GMA-UD2H rev 2.0 motherboard and I can't run a stick of memory in ram slot 2 or 4. Single sticks work fine in slots 1 and 3. But if I try 2 sticks in slots 1 & 2 or in 3 & 4 (which is supposed to be dual-channel mode according to the manual and on board color-coding) it won't post. It just gives 3 long beeps. Right now I am running 2 sticks in slots 1 & 3, but that is not dual-channel (confirmed by cpu-z). Is this motherboard ok?

The memory is G.Skill Ripjaws 2 x 4GB DDR3 1600 and bios settings for memory are default. Cpu is Phenom II x3 720 oc'd a bit to 3.2ghz, not unlocked.


edit: added snippet from manual

So, if the manual is right(!), Channel 0 => 1 & 3 and Channel 1 => 2 & 4.
But, the table to the right suggest that for 2 modules, I use either 1 & 2 or 3 & 4.

 

[corkyg]

Don't you have to change the single to dual in BIOS before booting? In my quad system, default is single channel.

 

[eflat123]

As far I can tell from the manual (page 16), there isn't a bios setting for it. It should be a matter of populating the slots right. Dual should be slots 1 & 2 or 3 & 4, but the problem is that it won't post if I'm using 2 or 4.

It seems like it's a motherboard problem to me. What kinda of testing would you do to narrow it down to that? I've run memtest and the sticks are fine in slots 1 & 3. Or does anyone think there's a setting I'm overlooking?

 

[corkyg]

I beleieve the DIMM sticks need to be identical. My Asus board has a BIOS switch.

 

[denis280]

this is how it works. with 2 ram it's slot 1 and 3.or 2 and 4. in the manual it is not very clear.but after reading a little more you will understand.

 

[stargazr]

this is how it works. with 2 ram it's slot 1 and 3.or 2 and 4. in the manual it is not very clear.but after reading a little more you will understand.

That's usually correct, but not with his board. Channel A is slots one and two; channel B is slots three and four.

Edit: Sorry you are correct, that's what the manual says.

My gf has a AMD machine, I used an Asus M4A785TD-M EVO mb and the manual says the same thing - slots 1 & 3, and 2 & 4. But for dual channel I need to have the 2 sticks I use in slots 3 & 4. I can't remember anymore but it might have something to do with ganged vs. unganged setting in the BIOS. It has to do with the relationship to the cpu cores I think.

 

[eflat123]

What I'm gathering from the manuals is that this first rev of this motherboard has the ram slots side-by-side per channel, and the 2 newer revs that was changed to be alternating. Dunno if that's fishy or if it's just what it is.

Tried clearing cmos, running the ram slower, still same. May just be ram incompatibility. I'll have to scare up some other ram to test with. Anyone else here in Sacramento I could bum a couple sticks off? (might as well ask, eh)

 

[denis280]

but it might have something to do with ganged vs. unganged setting in the BIOS

Did you recently change the cpu on this mobo.did change mine from athlon to phenom and started to get the same issue.and bsod so i changed the setting from unganged to ganged

 

[Charlie98]

There should be a setting in the BIOS for your memory.... I'm using a low-end Giga board (D2H) and mine has it. You may have to dig around a bit to find it...

EDIT: No, you may be correct... I have rank and channel interleaving, but not channel control (unless that's what channel interleaving is...?)

 

[stargazr]

Did you recently change the cpu on this mobo.did change mine from athlon to phenom and started to get the same issue.and bsod so i changed the setting from unganged to ganged

No, it's still an Athlon II X3 445. Wow, old thread.