P45 Platinum Optimum memory settings with 2GB Corsair 1066 memory

Question

Hi all,
Looking for some advice on optimum memory settings as I seem to have been getting unstable results from experimenting with settings and the optimum defaults.
My configuration is as follows:
MSI P45 Platinum (V1.0 PCB) (V1.4 Bios)
Intel Dual Core Duo E8500
Corsair TWIN2X2048-8500C5D DDR2-1066 5-5-5-15-2T configured for 2.2v in Bios
Palit 9800GT
2 x Maxtor 1TB HD's
1 x Floppy + Memory card readers
2 x Samsung DL-DVD-DW's
Silverpower SP-400P2C 400W PSU
With the default optimised settings loaded, the system does not book reliably or pass the memory test, in fact memtest86 just hangs when booted
With the Memory configuration set to 1:1.33 (1600:1066) the systems appears to pass the memory tests and windows is relatively stable. Voltage set to 2.2volt with Spead Spectrum disabled.
Is this really the optimum configuration ? as the Adjusted DRAM Frequency reported by the bios is 887 and I was expecting to see 1066.
Any suggestions as how to optimise reliably would be appreciated.
Although I suspect I may have a PSU issue as once booted the system locks when running any 3D games/demo's and it looks liek the 9800GT's need a lot more amps that I thought when putting the system together.
Rgds

Answer 1

Quote from: sylvester on 11-October-08, 20:43:36
Intel Dual Core Duo E8500
Corsair TWIN2X2048-8500C5D DDR2-1066 5-5-5-15-2T configured for 2.2v in Bios
With the Memory configuration set to 1:1.33 (1600:1066) the systems appears to pass the memory tests and windows is relatively stable. Voltage set to 2.2volt with Spead Spectrum disabled.
Is this really the optimum configuration ? as the Adjusted DRAM Frequency reported by the bios is 887 and I was expecting to see 1066.
First of all, your DDR2 modules are in fact DDR2-800 (they're using overclocked-overvolted DDR2-800 chips).
Sencondly you need to understand how a FSB/DRAM divider works.
Your processor is Intel E8500 and that means a bus frequency of 1333MHz (333MHz quad-pumped).
In your case 1:1.33 means 1.33 x 333 x 2 = 887 MHz for the DDR2 modules.
Set the divider to 1:1.6 if you want the DDR2 modules to run at 1066MHz.
And finally, the "optimum configuration" for max system stability means real DDR2-1066 (7-7-7-20 at 1.8V) or
DDR2-800 (5-5-5-15 at 1.8V).
cheers