bandwidth disparity

[mk17]

Hi everyone. I have a quick question regarding memory bandwidth:





On int buffered my machine runs between 20-30% faster than the comparisons. But for float buffered tests my machine sinks to about 20-25% of comparisons.

Running Corsair [email protected], 4:5 (800MHz)@5-5-5-15.
[email protected]. MCH @1.53v. Abit AW9D-MAX.

MemTest runs happily for hours. But something seems badly wrong with the Bandwith Efficiency falling to 8% for float.

Has anyone any ideas? Does this look like a voltage issue? Or is my ram hosed?

 

[mk17]

Thanks for the responses guys.

Everything reset to default (cpu, ram volts, mch, etc.):


Defaults plus a bump for Ram V, and MCH:



Stock speeds seem to indicate that the ram doesn't like 1.80v very much. However this doesn't explain the poor float performance.

Anyone got any ideas? Should the MCH be pushed further, i.e. ram @ 2.1, mch @ 1.6?

 

[mk17]

found it:




Turned out to be an AW9D mobo issue. I downloaded a beta of bios v13, problem solved. I haven't tweaked it for performance just yet, its not as stable as 12 was, but it has unlocked the multi to go higher than 11 (31x I think).