I want to build an 8 core computer with two Q9450 processors. Which motherboards can support 2 of these processors?

I dont think you are going to fins a motherboard that has two 775 sockets. going to have to use 771 Xeon processors. and use FB-dimms for memory. You can find 771 Xeon with same specs as the Q9450. Good luck and what are you going to use the computer for. Do not see why you want 8 core computer.

None... normal S775 boards aren't designed for dual socket. You'll need to use a workstation or server board and yes... FB-DIMMS. You could go AMD to avoid FB DIMMS but for a non server workload that wouldn't really do you much good.

-mcg

Wait for Nahlem if you need more then four cores.

I have a similar problem...
I want t0 get 6 Intel Xeon X7350 Tigerton 2.93GHz 2 x 4MB L2 Cache LGA 771 130W Quad-Core Processor's and linc them T0getharz with pink wires...
I'm stiel l0okin for a good motterbaord for it, maiybeyy 3 motherbaords witch i can alsoo l!nk togather with brown wires...
N0VV tha reeson I need all the (2500 a piece) CPUs is becoos I ned to plai runescape with desent settiengs...

Srry joking
Serious man, why do you need the 2 uberexpensive CPU's??

i thought i was reading a serious post by some nub dutch kid. that was pretty funny especially the pink wires and the runescape part lol

I render 3D animated scenes. For this the processor power will never be enough. I thought I could get away with cheaper solution than spending $5000 for 8 core Mac Pro or equivalent PC. For now it appears that I can't do that but I'm still searching.
Nahlem will be a big boost for this but I can't wait that long.

You can certainly do better than $5000:
Skulltrial motherboard: $660
http://www.newegg.com/Product/Prod [...] 6813121330
It's more expensive than most server motherboards, but is the best overclocking board in existance, compared to server boards, which do not oc at all. Overclocking matters a lot when you have 8 cores running at 100%. There's also support for both sli and crossfire, not sure if graphics card matters in animation rendering though.

Lga771 45nm, 12mb cache, Harpertown quads, counterpart to Lga775 q9450, which is also 45nm, 12mb cache, but codenamed Yorkfield.

2.0ghz: $230
http://www.newegg.com/Product/Prod [...] 6819117151
2.33ghz: $275
http://www.newegg.com/Product/Prod [...] 6819117149
2.5ghz: $345
http://www.newegg.com/Product/Prod [...] 6819117147

All of them can be overclocked just as well as Yorkfield cpus.

+1 for skulltrail mobo, stick in two q9450 or Xeon counterparts and overclock them, and it should render fine. Im not sure how much animation rendering uses in ram, but maybe 4gb minimum would help.

socket 775 does not support multiple sockets. If you want multiple sockets you have no choice but to go socket 771. Which are exclusive to the Xeon 5000 series. I wouldn't recommend the 7000 series.

Skull trail uses socket 771. It IS a server board with pci-express support.

Thanks for the info dagger and all
I wonder what makes skulltrail different from other dual socket motherboards like these:
http://www.nextag.com/dual-socket- [...] earch-html

Most of those aren't even Intel lga771, and those that are do not support newer 45nm quads. The ones that do cost around $400, $200 cheaper. But they don't allow overclocking. Server equipment do not focus on oc. An old 65nm quad easily oc from 2.4ghz to 3.6ghz, a 50% increase in speed. 45nm quads should do as well, if not better. Then there's graphics card support for sli/crossfire. Not sure if you need it though.

Of course, if you don't bother oc, and don't care about graphics, it's a $200 savings.

dagger, so you are saying 8 cores (2 quad core processors) using 2.5ghz E5420 Xeon can be overclocked to run about 50% faster if used with Skulltrail? Will this beat by a big margin one overclocked quad core Q9450?

I appreciate your help a lot.

I'm not sure how well lga e5420 oc, but it's safe to say it should do at least 30%. It's basically the same as q9450, and should perform similarily.