A8N-VM CSM + 4 x 512MB VS1GBKIT400 won't post 400Mhz ?!

A8N-VM CSM + 4 x 512MB VS1GBKIT400 won't post 400Mhz

I got it to post 400Mhz with 2x 512MB, but it will only post 333Mhz with 4 x 512MB.

MB: Asus A8N-VM CSM bios 506 (uses nForce 430 MCP)

CPU: AMD Athlon 64 +3200 Venice

RAM: 4 x 512MB dual channel VS1GBKIT400

I've read that the Athlon processors feature the memory controller inside the CPU and that they can have issues with 4 modules being installed, and defaulting to 333Mhz instead of 400Mhz. I tried setting specific timing information to fix it, but it still posts 333Mhz. When I had 2 x 512MB installed it was able to post 400Mhz. Spec says my DDR is 2.5-3-3-8 timing

What should be my timings or another fix please?

Memclock: Auto or 200Mhz?

MCT Timings: Auto or Manual

CL: 2.5

TRAS: 8T

TRP: 3T

TRCD: 3T

TRRD: ?

TRC: ?

TRFC: ?

TRWT: ?

User Config mode?

Read Preamble: 9.5ns?

Async Latency: 11.0ns?

CMD-ADDR Timing Mode: 2T?

Burst Length: 4 beats?

Software Memory Hole: Disabled?

Any help greatly appreciated...

Early Venice controller? But I just bought it from NewEgg 3 weeks ago...

Here is what CPU-Z says:

Name: AMD Athlon 64 3200+

Code Name: Venice

Brand ID: 4

Package: Socket 939

Technology: 90 nm

Voltage: 1.45 v

Family: F

Model: F

Stepping: 0

Ext. Family: F

Ext. Model 2F

Revision: DH-E3

The Maximum PC article said the nForce memory controller in Venice 90nm had an improved memory controller, and if it's "rev e" it should be able to run both sets of RAM as DDR400.

After some research it appears to be an AMD cpu memory controller voltage issue. Single rank = single sided RAM, Double rank = double sided RAM.

I have the newer venice core CPU, so I should be able to do 400Mhz with 4 RAM modules.

Double rank - Double rank - Double rank - Double rank - DDR400

Asus has rigged the bios to default to DDR333, but changing the timing settings should force it back to DDR400.

I changed my setting to 2T in the BIOS but it still posts 333Mhz.

I also tried setting CL 2.5, 3-3-8.

MEMCS_1L_L* - MEMCS_1H_L* - MEMCS_2L_L* - MEMCS_2H_L* - 1T - 2T

Single rank - Single rank - Empty - Empty - DDR400.....DDR400

Double rank - Double rank - Empty - Empty - DDR400.....DDR400

Empty1 - Empty1 - Single rank1 - Single rank1 - DDR333 - DDR333

Empty - Empty - Double rank - Double rank - DDR400.....DDR400

Single rank - Single rank - Single rank - Single rank - DDR333.....DDR400

Single rank - Single rank - Double rank - Double rank - DDR200.....DDR400

Double rank - Double rank - Single rank - Single rank - DDR200.....DDR400

Double rank - Double rank - Double rank - Double rank - DDR200.....DDR333

The above chart shows what a Winchester and below can do.

The Venice core will change one small detail from that chart, the ability to use 4 slots of SINGLE sided ram and get 1T DDR400.

Using dual sided ram requires 2T DDR400.

Well, no amount of memory tweaking would let me post 400Mhz.

Took Eclipse's advice and just went with overclocking (what little it can) to get back to 400Mhz RAM.

200 x 10 changed to 240 x 10

+3200 now a +3400

167Mhz downgraded memory clock + 40Mhz x2 gets me back to 400Mhz.

240FSB is still fairly conservative for a venice core cpu.

I bought Asus for stability, and I got it, even if it was shoved down my throat.

I just wish I knew about the venice core being 6 rank limited.

Would have spent more for single sided RAM.

Prolly would have overclocked anyways.