Ram issue - 4gb fine, any more = no boot

[Skinleech]

Hi folks,

Due to a few random issues with my old motherboard I recently changed it for a different board bought from a fellow forum member. After ironing out a few issues with the new board, the only problem I'm left with is with RAM.

My old board (Abit AB9 QuadGT) would happily run with 6gb RAM out of the box (2x2gb pair, 1x1gb pair). The new board (Biostar Tpower i45) runs fine with 4GB, but anything more than that causing the PC to power on, but no response. The onboard BIOS code display reads 18 (or 81?). I also have another 4gb set (2x2gb again) which works fine by itself, but causes the black screen with both sets installed.

All of theRAM has passed a memtest86+ test error free, so I did some googling and found some posts suggesting voltage could be the issue. Both of the 2gb pairs are rated at 1.90v, and looking in the I45 BIOS, it's only providing 1.88v (CPUID within windows seems to suggest that only 1.8v is making it's way to the chips). I tried a 0.5v boost giving me ~ 1.925v and bingo! the PC boots with all 8gb. After 10 mins or so though, it crashes.

So, I'm pretty new to messing with voltages, I guess I've been lucky enough to plug & play with everything, and have never really been into trying to overclocking.

Should I up the voltage further in 0.5v increments to see what happens? I don't want to risk over-volting the ram chips but I also don't know if the motherboard or CPUID are giving me accurate readings.

Any thoughts are welcome, thanks.

[Terbinator]

Try upping the Northbridge voltage as well.

[krazy_olie]

also mch voltage if it's available.

That much ram which isn't matched would put a fair amount of strain on the memory controller I think

[Sputnik]

That board had MIT memory test facility built into the BIOS so it can test the memory. If the memory pairs are not the same, you need to set the timings to the slowest pairs timings.

Also double check the slots configuration. I've seen boards that use one colour for each channel and other boards that use one colour for the first slot in both channels.

[Skinleech]

Thanks folks, there's deffo an MCH option in there so will have a look hopefully tonight - and the timings were set to auto, but that wasn't adjusting to the fastest RAM timings (the chips I have in currently) so I'll drop them down later & see what happens.

Will post back with my results.

Cheers.

[blueball]

about 0.1V extra on MCH may be enough.

[Skinleech]

Well, I tried yesterday.

Upped the RAM voltage up 0.5v, upped the MCH & Chipset voltages (think the option for both was *0.67, will have to check) but no joy. As described in the OP, the PC boots fine and runs fine for about 10 mins. After that it bombs out.

What I will say is that I've never tried to have these 2 4gb sets running together, just one fo the 4gb plus the 2gb set, so I should really be trying that 1st to see if there's an issue.

I took some screenshots of the BIOS options that I'll post later on.

Cheers.

[jim]

My X48 was incredibly unstable with 4 sticks of RAM. Not much you can do but kill all the overclocks, get everything back to stock, and start upping the voltages until it all works. Of course, you might blow it up in the process but that's life