Dual CPU Motherboards

[imported_BLUEman]

Hi everyone. This is my first post here in the AnandTech Forums. I have just a quick question regarding dual CPU motherboards: I'm thinking of building an Athlon 64+ 3800 for myself... and I came across a motherboard which has dual Athlon 64+ support. Do I need to have both CPU slots filled before I can get this PC working? Do I require one stick of RAM for each CPU (I've noticed that each has it's own little "ram slot.")? Thanks.

Apparently the link does not work. Here it is on it's own: http://www.msicomputer.com/product/p_spec.asp?model=K8T_Master2_FAR&class=mb

 

[yankeesfan]

link doesn't work

 

[imported_BLUEman]

I've added a new one to the bottom of the post.

 

[SUOrangeman]

The board will work with only one CPU. However, you will have to use a 940-pin CPU (Opteron). If they still make 940-pin FX CPUs, they will work as well. I'm not sure if 939-pin FX CPUs will work. $$$ > than an Athlon 64.

-SUO

 

[yankeesfan]

i am not an expert on this topic, but i think that you can run only one cpu, and they both need ram. you also need the socket 940 cpu's, which are very expensive, and registered ecc ram, which is also really expensive. furthermore, socket 939 is much cheaper, but if you have your eyes set on dual processors, this will be very fast. the opterons are cheaper, i believe, than the Athlon 64 FX series.

and now i see that you are going to use a socket 939, but this motherboard does not support the processor you are suggesting.

 

[Markfw]

As others have said, the 3800+ is socket 939, and ALL dual(and 4 and 8 way,etcc) socket motherboards for AMD processors are socket 940 (not including the old socket A duals).

First question would be why you want a dual processor motherboard ? Only a small amount of software can make use of it. I like the multiprocessing abilty(crunch F@H and run Far Cry at the same time) AND the 64-bit PCI-X slots for my SCSI card.(most important, leaves PCI Express in the dust at 1x, only has one x16 slot)

So decide what you need it for, and if you need it. Then decide on the motherboard, then which processor(s) to get, in that order.

 

[azazal]

hmm, does the cpu speed not stack then, and give u like 4.4 ghz with the a64? or does it work by sharing the load, ie in a hyperthreading manner, not increasing overall performance, but making multi tasking easier?

 

[yankeesfan]

it will not operate at the speeds of a 4.4 ghz Athlon 64. In some programs, you will benefit from the two processors, but not games, etc. Multitasking will improve with two cpu's, i believe. As Markfw900 stated, only a small amount of software will be able to make use of it.

 

[Markfw]

Yes, it does not stack. It is true multi-processing, unlike HT. HT optimises the core to make better use of what power in cpu cycles are available, thats all. Dual CPUs can truely process 2 tasks with the same power for each one, so in my case, I can get 100% of one CPU doing F@H, and still have one full CPU for Far Cry. (or 2 F@H when not playing). But at quite a cost. The motherboards are about 2x-4x the price of a single cpu board ($436 for mine) and teh memory is a little more ($614 for 2 gig) and the processors are not cheap (248 Opteron at 2.2 ghz=$700 each approx)

 

[imported_BLUEman]

Thanks for all the help everyone. I greatly appreciate it.