SMP with unregistered ram?

I'm starting to research into SMP, as I need to run some monte carlo simulations over the next 2 to 3 years (at least).

I need to have control over which CPU does what. That way I can surf/server/ WoW on one cpu, and run simulations on the other CPU. However, I really dislike the notion that I have to use registered ram (it's too expensive).

Could anyone point me in the direction of a MB (intel or AMD compatible) that can SMP without using registered ram? Also, if the board can run dual core CPUs , that would be a major plus.

I have searched newegg, but their descriptions of ECC ram support is simply a "yes" and does not say whether or not it supports unregistered ram.

What you are planning is a bad idea. Almost never will you do a better job assigning CPUs than the OS scheduler.

The only current platform with more than one CPU socket and unregistered RAM is AMD's "4x4".

Given the overall state of that platform, I really don't see why you don't go Intel quad-core on 775 or registered RAM. It's not that much more expensive.

uOpt said:

What you are planning is a bad idea. Almost never will you do a better job assigning CPUs than the OS scheduler.

The only current platform with more than one CPU socket and unregistered RAM is AMD's "4x4".

Given the overall state of that platform, I really don't see why you don't go Intel quad-core on 775 or registered RAM. It's not that much more expensive.

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I'm wanting the 1 cpu to run the simulation unhindered (IE nothing else on the CPU and it only running ON that CPU). That way when I'm playing WoW/whatever, the game play is unhindered. Will the game play be unhindered either way?

No, because memory and disk will still be a contested resource, and by allocating CPUs to processes hard you force the OS to take unnatural actions when processing system calls. Speaking of system calls, you are still subject to the OS kernel running on any processor even if you bind the userlevel programs.

You should just set priorities (not affinities) so that half of your box is for the simulation. If you just run one additional process (the game) and you have 2 CPU then that is the default.

It will still suffer, but it's the best you can do.

Also might I ask why not go with a C2D or X2? Or maybe you want a quad core? (Although that seems an overkill). These will be cheaper and overclock higher than any SMP setup, and you'll still have two cores for multitasking.

Current 771 xeons require FB-DIMM ram which is $$$. There isn't a board out that will run them with DDR2 ram.

There are only three more platforms that will by SMP and use DDR/DDR2 ram. That would be old AlthonXP CPU's in SMP configuration. Or some old socket 604 xeons in a PC-DL or any other overclocking board like it. And as already mentioned the 4x4 from AMD.

I still think sticking with a single CPU but multicore is your best bet.