F2-8500CL5D-2GBPK + Asus M4A785-M

[ChrisW]

Since the M4A785-M detects the memory as DDR-800, I have to manually configure this memory for 1066 speed. These are the settings I have gathered by using CPUID and other programs:
Memclock Value=533
TCL=5
TRCD=5
TRP=5
TRTP=4
TRAS=15
TRC=48
tWR=13
TRRD=4
tWTR=4
Memory Overvoltage=2.1v

One problem is TRTP has two selections (2-4,3-5). I guess I set it to 2-4?
Also, I can't set TRC to 48 since it only goes up to 41 in the BIOS.
Also, tWR can't be set to 13 since the BIOS only lists 5,6, and 8.

The other unknowns are:
tRWTTO
tWRRD
tWRWR
tRDRD
tRFC0
tRFC1
tRFC2
tRFC3

This memory is on the official ASUS supported list. What are the exact settings I'm supposed to program into the BIOS?

One more question. If I try to overclock my Sempron 140 (by changing the FSB) and I set the memory to DDR-800 so I can overclock toward 1066, should I set the memory timings and voltage for 1066 speed?

[Tradesman]

Couple of things, first ensure you have the latest BIOS, can be found here:

http://usa.asus.com/product.aspx?P_ID=ef0qgvMIwOUagAVl

Next, the latest BIOS 'may' free up some of the available timing issues, but the thing to keep in mind is that while the mobo may be rated to 1066/1200 RAM, like any other mobo, the rating in part is determined by the CPUs it takes. Your mobo will take up to a AM3 (where the 1200 RAM floats in), so you may or may not be able to hit 1066, and to do so, may have to loosen the timings. Best bet may be to run at 800 with stock timings (entered manually, and command rate/timing at 2N or 2T) and then to try and tighten timings.

[ChrisW]

Yes, I'm running the latest BIOS (506) and the Sempron 140 is an AM3 processor. When I set the rest of the values to auto, this is what they are set to:
TCL 5
TRCD 5
TRP 5
TRTP 4
TRAS 15
TRC 32
tWR 6
TRRD 7
tWTR 7

tRWTTO 6
tWRRD 1
tWRWR 1
tRDRD 2
tRFC0 127.5ns
tRFC1 75ns
tRFC2 75ns
tRFC3 75ns

I'm currently running at 1066 dual channel, but occasionally get a blue screen or Windows reports a memory error.

The SPD EPP#1 values read by CPU-Tweaker 1.3 show they are supposed to be set to:
TCL 5
TRCD 5
TRP 5
TRTP 4
TRAS 15
TRC 48
tWR 13
TRRD 4
tWTR 4

tRWTTO ?
tWRRD ?
tWRWR ?
tRDRD ?
tRFC0 ?
tRFC1 ?
tRFC2 ?
tRFC3 ?

I can't set TRC to 48 since it only goes to 41. TWR also can't be set to 13. I still can't figure out what the values marked with a question mark are supposed to be set to.