Question memtest86+ 5.01 reports DDR3-1066 single channel speed as 1257MB/sec

[mikeymikec]

I don't use memtest86 (whatever version) as a memory benchmark, I'm just testing out an old rig to see whether it's in a condition worth selling. IIRC I'd expect DDR3 to be giving a figure of something like 4GB/sec in memtest86+ though. Typically I'd expect to see DDR3-1333/1600 (I've never bought anything slower unless it was absolutely necessary), so I'd expect 1066 to have less throughput, but that much less seems suspicious.

Does anyone have a system handy that they could check what figure memtest86+ 5.01 gives them for single-channel DDR3-1066? The CPU in this system is an Athlon II X4 640 so I know with reasonable confidence that is unlikely to be the problem.

IIRC, dual-channel DDR1 would give me a similar figure let alone DDR3!

- edit - I tried another module instead, DDR3-1333. Slightly better reading with SMP on (13xxMB/sec), much better reading with SMP off (28xxMB/sec). Still seems off though, and I don't recall SMP in memtest86+ causing that much of a disparity for that figure before. I guess it's been a while since I did an AM3 build though 🙂

I'm wondering whether a BIOS update might improve matters, though I've noticed that this is probably a crappy low-end board as it doesn't even support AHCI. ASROCK N68C-GS FX.

 

[mikeford]

I'd start by looking at the bios setup, could be ram defaults or worse.

 

[VirtualLarry]

Are you running memory channels A and B, as "ganged" or "unganged"?

 

[mikeymikec]

single module, if I had to guess it's in channel B. Unganged, I checked that. I'll try switching slots, reset the bios and see what happens.