* * MAJOR GAINS? Dual-CPU MOBO Primer * *

[silicon demon]

i'm interested in what gains can be had from a dual-cpu motherboard. i haven't found any recent articles on AT on this subject.

this all started when one particular member posted their rig, which boasted a Tyan Thunder K8WE S2895A2NRF...running Dual AMD Dual-Core Opteron 280s (2400MHz).

(Wow...dual-core in a dual-CPU set-up!....Needless to say, got me to thinking.)

Can these mobos be used in regular PCs, or are they for dedicated workstations using non-Windows operating systems? And are the gains in sequential speed, or more in parallel processing power? And are those gains significant?

 

[ProviaFan]

Originally posted by: silicon demon
Can these mobos be used in regular PCs, or are they for dedicated workstations using non-Windows operating systems?

Software-wise, a dual core dual CPU system can run Windows XP Pro just fine. However, the Tyan K8WE is an Extended ATX form factor motherboard, so it requires a special kind of computer case that you most likely don't already have on hand.

And are the gains in sequential speed, or more in parallel processing power? And are those gains significant?

The only gains from such a system would come while running software that runs at least four threads for processing simultaneously, or from running several computationally intense programs at the same time. For most power users, a dual core processor on a single-socket motherboard is all that makes sense from a performance / cost perspective.

 

[silicon demon]

Nice to see you again, Provia

The only gains from such a system would come while running software that runs at least four threads for processing simultaneously

is there an easy way to tell if your software app does this? i guess you could run it and maybe just see it in the Task Manager?

Also, if you want to use 64-bit processors/ operating system, do you have to specifically match a mobo to this requirement?

 

[ProviaFan]

Originally posted by: silicon demon
Nice to see you again, Provia

The only gains from such a system would come while running software that runs at least four threads for processing simultaneously

is there an easy way to tell if your software app does this? i guess you could run it and maybe just see it in the Task Manager?

It's hard to say... On the Mac side, where they now have a four-core system, tests with Photoshop show that some filters benefit from more than two cores, while others show no increase in speed. I'm afraid that the only way to tell for sure without trying it yourself (way too expensive, naturally) is to ask the people who wrote the software. Edit: to explain further: if the software is automatically detecting how many processors are available and making a suitable number of threads to match, then you won't be able to tell whether or not it can make more than that number of threads just by looking in the Task Manager of an ordinary single or dual core system.

Also, if you want to use 64-bit processors/ operating system, do you have to specifically match a mobo to this requirement?

As far as I know, all Opteron dual core / dual CPU and all Athlon 64 dual core systems support Windows XP x64, though you may have some other peripherals that don't have the necessary 64 bit drivers. With Intel Xeons and P4's, you'd have to check carefully to see if the system that you're interested in has the "EM64T" extensions (Intel's version of AMD's 64 bit extensions) or not.

 

[silicon demon]

cool...

you've seen me hard at work here.

After all my questions, i'm really starting to lean toward the Athlon 64 X2 4800. I'm not really hip to dual-cpu boards so when i saw SagaLore's rig it was an eyeful. I guess it could get pretty expensive doubling up on the processor. If you would, let me know if you run across any comparisons or other links on this subject.

and thanx.