Background: I had upgraded to 4g of ram (2x2g sticks ddr2 667). The ram was not a dual channel kit, but identical types with same lot numbers (so essentialy a dual kit). Anyways, it was sometimes running dual channel, sometimes single.

I thought that was odd but figured it must be because it wasn't a dual kit. So I return the ram, buy a pc6400 dual channel kit, and now it appears that only one ram slot is working.

I've switched both sticks around to the other slot (I only have 2 dimm slots), and according to cpuz its always slot 2 that is reading the memory, it shows slot 1 as empty.

So I take that to mean nothing is wrong with the memory, but something is wrong with slot 1. So would you say its time for a new motherboard? ANy other suggestions, diagnositcs I can run?

Thanks for any help.

Did you try a couple of 1G sticks to see if the problem is only with 2G sticks?

If it is with 2G sticks, and the board is supposed to support 4G you can try bumping the mem voltage &/or northbridge voltage up a bit to see if it needs a bump to work properly.

the board is this one:

http://www.msicomputer.com/product/p_sp ... L&class=mb

its supossed to support 2g sticks up to 800(pc6400).

Its says the mb supports 1.8v ram, so I bought this dual channel kit to stick with the 1.8v

http://www.valueram.com/datasheets/KVR800D2N5K2_4G.pdf

do you think its a voltage or timing setting?

I'm thinking that since it recognizes one slot, then it might not be the ram. But do you think there could be a conflict or setting that I can change? I'd love to avoid a repair (my computer is under warranty, but it was a staples clearance computer and they would probably have to ship it off for warranty work - I'd be without my comp for god knows how long).

Unfortunately if it's one of the big box pre-builts I doubt you'll have the settings you need in bios.

The only suggestion I can make is to bump Vdimm or your northbride volts, and I doubt very much you can do that in bios.

The other issue you'll have now is that your OS is tied directly to your motherboard so you wouldn't be able to use it with a different motherboard.

Also keep in mind that the bios on the board is more than likely not the same as the generic one from the MSI site and that attempting to flash it will probably turn it into a brick.

Pre-built manufacturers like dell/compaq/HP/Acer use the same model#s on their motherboards, but they change the bios/firmware to prevent folks from playing with the bios settings. 99% of these boards are not compatable with the stock bios flashes.

okay thanks for that info. The computer is a zt brand - I figured it was a staples only thing like cisnet used to be. I won't upgrade the bios then, just in case.

Could timings be an issue? The ram is (i believe) supossed to be 5-5-5-18 and cpuz reports the one slot as 5-6-5-18. I am able to manually adjust timings in the bios, but I didn't want to attempt it, as I've heard of people having to clear cmos afterwards, and well then I'd be screwed because of the manufacturer bios reasons you've just stated.

I may have to just bite the bullet and send it off for repair. Or just live with a one slot 2gig system - goodbye to any decent gaming at all

Have you tried bumping the voltages in bios? If it's a staples brand rather than one of the big pre-built models, it might not be a proprietary motherboard, and may have settings for voltage.

If it does have voltage settings, try setting the memory voltage to 1.9 or 2.0.

no voltage settings, only ram timings.

turns out zt is a large pre-built manufacturer in the states http://www.ztsystems.com

I'll buy and experiment later with a 1g pc5300 stick, as thats what was shipped with the system, see if both slots work then.

so here's the update, this seems odd to me:

I went out and bought a 1g stick of pc5300 ram (it was late saturday, went to futureshop and they had no 1g pc6400). I can put the 1g stick into slot 1, 2g into slot 2 and I get 3g of ram - each stick reads fine in cpu-z. So its not the motherboard.

But if I put either of the 2g sticks in slot 1 (I tried both) with the 1g stick in slot 2, only the 1g works.

So it appears that slot 1 will not take the 2g pc6400 ram.

The previous ram I had was 2g sticks of pc5300, it always read the 4g just fine in both dimm slots, but didn't always run in dual channel.

So now I'm hoping that if I put a 4g kit of dual channel pc5300 ram in (robotnik has a kit of kingston, only its kingston value ) then maybe it will work.

Or maybe a different brand of pc6400 might work?

My motherboard specs state 1.8v ram, so what would happen if I put say 2.1v ram in? There's this little bit of info on the website:

"Due to the High Performance Memory design, motherboards or system configurations may or may not operate smoothly at the JEDEC (Joint Electron Device Engineering Council) standard settings (BIOS Default on the motherboard) such as DDR2 voltage, memory speeds and memory timing. Please confirm and adjust your memory setting in the BIOS accordingly for better system stability.
Example: Kingston HyperX DDR2-800 PC-6400 operates at 2.0V, 4-4-4-12.
For more information about specification of high performance memory modules, please check with your Memory Manufactures for more details"

Does that just mean that if I had a fully capable bios, I'd be able to change the ram voltage? Am I safer to just stick with 1.8v ram?

Thanks for the help, I really do appreciate it.

Exactly. You've got it.

Definately avoid memory that requires higher voltages if you can't change the voltage in bios. My Ballistix won't boot on my DFI board until I boot with another set of ram and bump the voltage up.

I've had a lot of luck with the 1G supertalent sticks as far as booting on any board I've thrown them at goes. It's a pity that MB doesn't have any of the 4G supertalent sets in stock, but you could call and ask if they've got any in the back you could test with.

Well I grabbed a 4g dual channel kit of pc5300 kingston ram (1.8v) and all seems to be working fine.

Its strange that this board din't like the pc6400 ram, considering it suppossed to support it. Maybe a bios update would have fixed it, but I'm not chancing it for a mere 5% increase in performance.

Don't knock that 5%, you never know when yer gonna need it!