Can any Asus A8N-SLI users out there answer a queston about RAM compatibility?

[Glendor]

My Abit AN8-SLI cannot run my RAM at DDR400 speeds when all four banks are full; it can only do DDR333 in that situation. I read the DFI manual, and it said the same thing. The Asus manual for the A8N-SLI said it could, but depended on the make/model of the RAM.

My question is:

Does anybody have 4x Corsair CMX512-3200XLPro in their Asus A8N-SLI, and if so, does it run at SPD timings, DDR400?

Thanks,
Glendor...

 

[Makaveli]

You might want to list what processor you are running in the board. Athlon 64's prior to revision E have this limitation!!

 

[tcsenter]

Actually, all AMD64 processors have this limitation if all four modules are double-rank. Rev. E and later only adds support for one additional DIMM rank (five vs. six).

Maximum # DIMM ranks supported @ DDR400 (2T) = 6 ranks

Four double-rank DIMMs = 8 ranks

You'll have to override the auto-configure by SPD and manually set the DRAM frequency to DDR400 @ 2T.

 

[secretanchitman]

Originally posted by: tcsenter
Actually, all AMD64 processors have this limitation if all four modules are double-rank. Rev. E and later only adds support for one additional DIMM rank (five vs. six).

Maximum # DIMM ranks supported @ DDR400 (2T) = 6 ranks

Four double-rank DIMMs = 8 ranks

You'll have to override the auto-configure by SPD and manually set the DRAM frequency to DDR400 @ 2T.

:thumbsup:

even my opteron 170 has this limitation, so i stuck with 2x1GB of ram and probably will upgrade to 2x2GB of ram when 2GB sticks catch up to at least 1GB sticks' overclockability.

 

[Glendor]

Originally posted by: tcsenter
You'll have to override the auto-configure by SPD and manually set the DRAM frequency to DDR400 @ 2T.

I tried that on Friday, and it will work to override the speed setting, but it seems unstable, and shuts down the computer while running benchmarks like 3DMark05 & 06.

I noticed that I also get errors in MemTest86 when running 4x DIMMs. No problems at normal speeds when only running one DIMM, or 2x of either set, but problems with 4x.

I tried 4x on another mobo, and it worked fine in MemTest86, no errors at all, so I can't say I have bad RAM.

Also, to answer an earlier question: I have an Opteron 165 at stock speeds.

Glendor...

 

[tcsenter]

You can approach this from a few different ways or a combination of them.

Increasing DIMM Voltage
Increasing CAS Latency (CL)
Relaxing DRAM Timings (higher numerical values)

Increasing voltage can result in higher temps or shortened life, while increasing CL or timings can hurt performance. With AMD64 there is a big performance hit between 1T and 2T CMD. A couple reviews have even found that DDR333 @ 1T with aggressive timings can perform no worse or even slightly better than DDR400 @ 2T with moderate timings. It depends on how far your RAM (and motherboard) can be tweaked at any given frequency.

Try raising the DIMM voltage in steps over the current voltage. e.g. 2.6V > 2.7V > 2.8V

Test using Memtest86 instead of booting into Windows (potentially risking data corruption).