dual-socket motherboard question

[Jacklty]

Hi, guys.

I plan to build dual-processor system using Opterons, but with my limited budget.
Can I buy one 2XX Opteron first and put it on dual-socket motherboard? (work like a single-procoessor system)

Another question, can one process use all the ram on the board? (From the manual, it said each cpu can only address 8GB of ram, to use all 16GB both cpus are required), so I am curious about if one single process can use all 16GB of ram.

thanks

 

[Zap]

Originally posted by: Jacklty
Can I buy one 2XX Opteron first and put it on dual-socket motherboard? (work like a single-procoessor system)

Yes.

I don't know the answer to your second question.

 

[jonnythan]

Out of curiosity, what are you doing that's going to use over 8GB of RAM?

 

[Jacklty]

Thank for the answer zap.

Actually, it is for my coworker's java program. He wanna dump all his data from database into memory (so far he got 4GB of data and keep growing), so his program will fetch data from ram instead of database (with sql statement) to avoid overhead, also he can off-load the database during the data processing.

 

[Peter]

Some boards do, some don't work with a single CPU. The reason is that Opteron 2xx has two HyperTransport links for I/O attachment on EACH processor, the 3rd interlinking the CPUs. Now if a higher performance board hangs the I/O off both CPUs, you're going to need them both.

E.g. NForcePro boards that use the full blown chipset, 2200 and 2050, typically will hang the 2200 off CPU1 and the 2050 off #2.

For the RAM, the same thing applies. Each CPU contains a RAM controller; with one CPU socket empty, the DIMM slots that attach to it are going to be ignored.

 

[Jacklty]

The motherboard I pick is Tyan S2882G3NR-D which uses AMD 8131 chipset.
Will that work fine with only one CPU (AMD Opteron 248) installed?

 

[Peter]

The AMD chips allow the same thing - hang the 8131 PCI-X tunnel off one CPU, and the 8111 southbridge off the other. Or daisy-chain the two on CPU #1.

Your best bet is to visit www.tyan.com and look for a block diagram. Download the manual and have a look. If all else fails, you certainly are welcome to ask Tyan presales support, wouldn't you think?

 

[Jacklty]

Just for the followup

Single processor (2XX opteron) works perfectly on dual socket motherboard (Tyan S2882D) with no problem so far.

Originally posted by: Peter
you certainly are welcome to ask Tyan presales support, wouldn't you think?

LOL, you are right. however until today, they still haven't replied me yet. Still waiting .. still waiting.... (May be they think I am not a valuable customer - using one opteron on their dual socket motherboard)

Guys, Thanks for the responses.

 

[Peter]

Well our best guess then is that this board hangs both the 8131 and 8111 chipset parts off the 1st CPU.

If you're feeling particularly sarcastic today, you might want to mail Tyan the answer to your own question. I would