Memory Bandwidth discrepency - ideas?

[M1key]

Guys (and gals),

Firstly I'll list my system:

Gigabyte GA-7N400-L1
AMD XP2200+
Chaintech Geforce 4 Ti4200
1x 512mb 333mhz
1x 256mb 266mhz (running dual DDR @ 300mhz effective)

If I clock my CPU to 13.5 x 150mhz (2029mhz as read by WCPUID) then my memory bandwidth results in sisoft sandra come in at around 1850 and 1680 (in work at the moment so cant give exact figures). However if I clock it at 13 x 150mhz (1955mhz) then my memory bandwidth results are 2150 and 1980 ish.

Bear in mind that I made no changes to RAM timings or any other setting. How could a lower effective CPU clock speed show such an increase in memory bandwidth?

Any ideas or suggestions appreciated.

 

[Noid]

I dont know either ... but ... timing is everything to memory sticks

I have similar results in my NF7,,,

I generally look for the 'sweet spot' ,,, (using 3dM01 as bench)

Getting maximum bandwidth, doesnt mean maximum performance.