Here's a question for you that I can't figure out (yet).

As most of you already know, about two weeks ago I got a Tyan Thunder K8SD Pro (S2882-D) motherboard along with two Opteron 246s. According to the motherboard manual, it says that it supposed to be able to support dual channel memory on a 128-bit memory bus (with bank interleaving). I have two Crucial 512MB PC2100 DDR SDRAM, ECC, Unbuffered and I've tried installing them into the slots as outlined per the motherboard manual and the system will not post with it. (i.e. I put one module in CPU0 DIMM1, and CPU0 DIMM2). I've gotten it to post with a module in CPU0 DIMM1 and CPU0 DIMM3, and I've also gotten it to post on CPU0 DIMM1 and CPU1 DIMM1.

Does anybody have any suggestions as to what else I can try? According to the motherboard manual it says that I do not have to have memory in CPU1 DIMM1-4 in order for the system to work. Any ideas?

I think with most dual channel setups your first and 3rd dimm slots are to be used. Other than that do you have any other ram layin around?

Quote: Originally Posted by Sparky I think with most dual channel setups your first and 3rd dimm slots are to be used. Other than that do you have any other ram layin around?

I do have another stick of 1GB Crucial PC2100 DDR SDRAM that I can pull to test with, but it should work with two DIMMs. If I remember correctly though, I think that my 1GB is non-ECC, unbuffered. Kind of iffy whether it would work or not.

Note: the board itself has 8 DIMM slots in a 4+4 configuration.

Hmm..it may be that it does not like to play well with the PC2100, your CPU might be trying to run it as DDR333 wich is what it will run at when more than 512K of memory is installed.

The latest revision AMD's finally support 1 GB of memory at 400FSB, just as a note, it may play better with your RAM, but I would try some DDR333 that is on the motherboards approved list first if you could borow some.

If the PC2100 is pretty old stuff, the information stored in the SPD might be causing your problems, have you tried setting the timings timings manually? (try something a bit looser than stock too)

How about turning off CPC? (T-1 is on, T-2 is off in the Bios)

The last that I remember, doesn't the Tyan require registered memory???

Quote: Originally Posted by Highperf15 The last that I remember, doesn't the Tyan require registered memory???

Officially, yes. Unofficially, it doesn't have to be. The system can run without registered memory. I think that the fact that it's unbuffered memory has little to do with why it can or cannot go dual channel. The specific speed also should not matter as well, because a) it's a Tyan board, and b) it's also detect, and unlike most boards where you can typically only go one speed step back; the Tyan has support from PC1600 all the way to PC3200.

I would be surprised that having registered memory would make that much of a difference in bank interleaving (which appears to be the problem.)