Mix n Match my Memory

[moonbit]

Edited
My original set-up:
A64 3000+
Asus K8N Dlx
2x512 Mushkin DDR433 (running at 400 speeds)

So I bought a 1Gb stick of TwinMOS DDR400. However, when I put it in, the computer wouldn't boot, saying "DRAM timings mismatch - system halted." I took it out, looked up the timings for new stick, and modified my system timings accordingly (Latency - 3, TRAS 8, TRCD 3, TRP 3).

Still didn't work. Now I'm stuck, and I'm hoping you could help:

Here're my options in the bios:

Memclock Mode: Auto, Limit (on auto) Switching to limit allows me to play with the Memclock to CPU ratio
Bank Interleaving: Auto, Disabled (on Auto)
CAS Latency: set to 3.0
TRCD: set to 3
TRAS: set to 8
TRP: set to 3
DDR Clock Delay: Auto (current), or the following settings - 50 22, 50 33, 50 44, 60 22, 60 33, 60 44

Here's what TwinMOS says about my new RAM:

T(RAS, Active to Precharge) - 8
T(RCD, Active to CMD) - 3
T(RP, Precharge to Active) - 3
Cas Latency - 2,5
Voltage: 2,6Vdimm +/- 0,1V
* Double Data Rate architecture
* MRS cycle with address key programs
*CAS latency: CL2, 2.5 & 3
*Burst length: 2, 4 & 8
*Burst type: Sequential & Interleave
* 2 variations of refresh
*Auto refresh *Self refresh
* Serial Presence Detect support
* 2 Banks to be operated simultaneously or independently

Is there anything I'm obviously missing, or something I can try that might work? Thanks.

 

[flexy]

well..you can always try and run stability tests (prime95, occt)...if it's stable, well then it's stable. 🙂

Combining is not a good thing....but as said...give it a shot.

 

[TheSiege]

if you put in a lower speed stick dont they all run at the lower speed?

 

[jackschmittusa]

Adding a stick of DDR400 should work, running the FSB at 400. OCing will probably be limited by the new stick.

 

[betasub]

Shouldn't be a problem, but you may need to set RAM timings (RAS, CAS) in the BIOS manually, because different default EEPROM timings of the two might not give you a stable setting if you use AUTO.

BTW, adding a single 1GB stick will force the memory into single channel mode (if that's a dual channel 939 system).

Originally posted by: TheSiege
if you put in a lower speed stick dont they all run at the lower speed?

That's what should happen, but if the DDR-433 is only running at 400 speeds, then DDR-400 will be fine.

 

[moonbit]

bump for my edit 🙂

 

[betasub]

Have you tried the 1GB stick by itself, and then adding the 512MB sticks in different DIMM slots?

 

[moonbit]

It works by itself, but still has the error when I add the other sticks in. (I only have 3 slots, btw.) I tried resetting the bios to let it auto-find the timings from the 1gb stick, and then adding in the other two, but that didn't work either.

I'm starting to wonder if this is an exercise in futility. :/