Questions about dual server CPUs

[frobot]

I have two Xeon x5650 CPUs and I believe these can be used in a dual CPU set up.
These are "server" processors which I don't really know anything about.
I know they use the LGA1366 socket, but what kind of mobo do I need to use them both at once? I have a feeling it will be expensive...
Are dual processors very beneficial for building just a home PC?
It would have 12 cores total if I'm not mistaken which sounds like overkill.
And is there anything special I need to know if I'm trying to build this kind of rig?

Also, these processors are 2.66 ghz and 6 cores a piece. The processor I'm running right now is a 3.85 ghz 6 core (i7 970 overclocked)
Which one would be faster?
The motherboard I'm using is an Asus p6 x58-e pro. Would the Xeon x5650 be compatible with this? I could always pop it in and see which one runs faster as far as single processors go.

 

[heero yuy]

ummm its dual cpu servers
and you have two? already? why D:?
as for the other bits
a dual cpu motherboard will be expensive

iirc server processors work somewhat differently to desktop processors or something (but i would still say the i7 is best for gaming - no game out there that i know of uses 12 cores O.O oh and they have 6 cores each but 12 threads so basicly you are technicly looking at 24 cores there)

and the xeon will fit as they are both 1366

 

[frobot]

I have two simply because you can use two at the same time so why not =)
I'm mostly into making my own games and doing my own programming, in which case 24 threads would be AMAZING.

 

[InvalidError]

iirc server processors work somewhat differently to desktop processors or something

They work essentially the same way except for the QPI between the two CPUs, high probability of having to deal with NUMA performance hits (threads scheduled on one CPU with some/most of its code/data residing on the other CPU's RAM) and a few other potential complications from having resources scattered across two CPUs and can completely ruin any performance gains from having extra cores if software and OS are not properly coded/optimized to avoid bottlenecks created by the added complications.

A single-CPU i7 without all the multi-socket complications would definitely be better for gaming which rarely leverages more than 2-3 cores and likely for most software that isn't optimized specifically for NUMA or similar setups.

This is somewhat analogous to faster single-GPU vs SLI slower-GPU: the SLI may be theoretically faster but the single usually leads benchmarks simply because it does not have to work around multi-GPU complications.

 

[InvalidError]

I'm mostly into making my own games and doing my own programming, in which case 24 threads would be AMAZING.

Good luck trying to split your game code into 24 meaningful active threads and manage to keep the whole thing in a consistent state without wasting more time on inter-process communications/synchronization than the time spent actually executing useful code.

 

[scout_03]

this is the king of board you need but your cpu must have the same specs so check carefully before you buy a motherboard http://www.newegg.ca/Product/ProductList.aspx?Submit=ENE&N=100007628%20600007999&IsNodeId=1&name=Dual%20LGA%201366

 

[frobot]

Good luck trying to split your game code into 24 meaningful active threads and manage to keep the whole thing in a consistent state without wasting more time on inter-process communications/synchronization than the time spent actually executing useful code.

Just depends on what I'm doing.
Some things feel like I can never have enough cores.

But here is the real question-
Should I build a dual cpu system to sell, or would it be more profitable, with time considered, to just try and sell the two processors alone?

 

[InvalidError]

Should I build a dual cpu system to sell, or would it be more profitable, with time considered, to just try and sell the two processors alone?

I'm guessing the CPUs are worth more sold separately than together in a complete system, likely easier to sell as well.

 

[scout_03]

made 2 separate system choose a board that support same memory speed as the cpu and your asus p6x68-e pro does not support the xeon see it's cpu list on asus

 

[MU_Engineer]

I have two Xeon x5650 CPUs and I believe these can be used in a dual CPU set up.

Correct.

These are "server" processors which I don't really know anything about.

Intel server processors have at least four advantages over non-server (non-Xeon-branded) processors.

1. All Xeons can use error-correcting (ECC) memory. No recent non-Xeon CPU can do so.
2. Some Xeons support the use of registered memory, which allows for more and larger RAM modules than with using standard unbuffered desktop/laptop type memory.
3. Some Xeons support being used in motherboards with more than one CPU socket.
4. Xeons have a stricter validation process than consumer parts. This is probably not a big deal as just about every CPU will keep on running until well after it is woefully obsolete.

I know they use the LGA1366 socket, but what kind of mobo do I need to use them both at once? I have a feeling it will be expensive...

You need a dual socket motherboard. They start off costing about what a high-end single X58 board does (around $300) and go on up to around $600 for one with all of the bells and whistles like an SAS controller, 18 DIMM slots, IPMI, and two northbridges/IOHs to provide 70+ PCIe lanes worth of bandwidth.

Are dual processors very beneficial for building just a home PC?

Usually not. They are worth their weight in gold if you do heavily multithreaded tasks like video encoding though.

It would have 12 cores total if I'm not mistaken which sounds like overkill.

Correct.

And is there anything special I need to know if I'm trying to build this kind of rig?

A few things.
- Most dual 1366 motherboards are extended ATX (12"x13") instead of standard ATX (12"x9.6") in size. You will need a case that can fit the larger board.
- 1366 server heatsinks bolt down, 1366 desktop ones use the horrid push-pin retention mechanism. If you have an aftermarket 1366 desktop heatsink that you can bolt down, not all dual 1366 boards can use 1366 desktop heatsinks due to clearance and mounting issues. Most server heatsinks suck, go get yourself a pair of Supermicro 4U workstation heatsinks or Noctuas if your favorite 1366 desktop heatsink doesn't work on your server board.
- Server boards can't be overclocked (except the EVGA SR-2).
- You can't generally set RAM timings on server boards, and setting RAM speeds is very limited. You can only use 1.50 volt or less RAM and the fastest it will run with X5650s is DDR3-1333.

Also, these processors are 2.66 ghz and 6 cores a piece. The processor I'm running right now is a 3.85 ghz 6 core (i7 970 overclocked)
Which one would be faster?

The i7-970 will be faster in gaming, the dual X5650s faster in multithreaded stuff like video encoding.

 

[frobot]

your asus p6x68-e pro does not support the xeon

It actually does support the xeon processors I just benchmarked them.
In a CPU only test, the i7 came out a little bit ahead.
Using 3Dmark 11 the xeon actually came out just a few points ahead, but I only ran one test.
They seem to be pretty close, but I think the i7 wins.

@MU_Engineer
Thanks for all that info! Pretty much everything I was looking for.

Edit:
Ut oh... now I have a problem. Once I put my i7 back in it is no longer overclocked...
And I don't know much about overclocking =(
Is there any easy way to get my old settings back?

 

[MU_Engineer]

your asus p6x68-e pro does not support the xeon

It actually does support the xeon processors I just benchmarked them.
In a CPU only test, the i7 came out a little bit ahead.
Using 3Dmark 11 the xeon actually came out just a few points ahead, but I only ran one test.
They seem to be pretty close, but I think the i7 wins.

The i7-970 is a six-core, 3.20 GHz CPU that can go up to 3.46 GHz in poorly-threaded tasks. The Xeon X5650 is an otherwise identical 2.67 GHz six-core CPU that can go up to only 3.06 GHz in poorly-threaded tasks. The ASUS board is a single-socket board and can only use one CPU, so the Xeon should be slower in any and every test that stresses the CPU since it is otherwise identical but clocked lower compared to the i7-970...assuming you did not overclock the CPUs. To see what the X5650s really can do, you would need to have a dual-socket board.

The test that the X5650 was a tiny bit faster in, 3Dmark11, likely was looking at your GPU's performance and not your CPU's.

@MU_Engineer
Thanks for all that info! Pretty much everything I was looking for.

You are welcome. If you look at my signature, you will see that my favorite systems are multi-CPU server setups. They are fun

Edit:
Ut oh... now I have a problem. Once I put my i7 back in it is no longer overclocked...
And I don't know much about overclocking =(
Is there any easy way to get my old settings back?

I'll bet putting in the different CPU reset your manually-entered OC settings back to defaults. You will likely need to re-enter them manually.

 

[frobot]

3Dmark is mostly a GPU benchmark but your score is definitely still somewhat determined by CPU too.
I did my own little benchmarks too, just looping through some simple code a certain number of times and seeing how long it takes.
The i7 was only at the most 10% faster which I didn't expect.

And it looks like I'm about to learn how to overclock.
On the bright side, I'll probably end up with a higher clock than I had before since I still had pretty low temps at 3.85 ghz. Might shoot for around 4.1 or 4.2

 

[intuitus]

I hope I am not breaking the rules by adding a question to frobot's original post but this discussion has answered a lot of questions I had already & I'm hoping to get one last answer.

Now, using the specs of frobot's dual Xeon CPU setup, if I was using something like Windows Server 2003 on this setup (I know old OS), as I understand it I'd need to get a license for each CPU...

The question I have has to do with RAM. If the mobo has 8Gb RAM, does that mean that each CPU would have exclusive access to a portion of the RAM?

So, if Windows 2003 (Standard) can use up to 4Gb RAM max, does that mean that each CPU would use 4Gb or is it still 4Gb RAM across the 2 CPUs?

Hope that was clear

 

[MU_Engineer]

I hope I am not breaking the rules by adding a question to frobot's original post but this discussion has answered a lot of questions I had already & I'm hoping to get one last answer.

Now, using the specs of frobot's dual Xeon CPU setup, if I was using something like Windows Server 2003 on this setup (I know old OS), as I understand it I'd need to get a license for each CPU...

Depends on your licensing arrangement with MS. If you don't have some sort of volume licensing arrangement, the number of CPUs supported by each Windows Server variant should be listed on MS's website. The OS will just not see any more CPUs than it is licensed for (e.g. seeing only two CPUs on a quad-CPU setup on a 2 CPU license Windows Server variant.)

The question I have has to do with RAM. If the mobo has 8Gb RAM, does that mean that each CPU would have exclusive access to a portion of the RAM?

So, if Windows 2003 (Standard) can use up to 4Gb RAM max, does that mean that each CPU would use 4Gb or is it still 4Gb RAM across the 2 CPUs?

Hope that was clear

I believe that MS's license terms are for total RAM capacity per board. If you have 8 GB on a 4 GB license, 4 GB of your RAM will be visible to both CPUs and 4 GB will be ignored. The CPUs share the RAM.

 

[intuitus]

I believe that MS's license terms are for total RAM capacity per board. If you have 8 GB on a 4 GB license, 4 GB of your RAM will be visible to both CPUs and 4 GB will be ignored. The CPUs share the RAM.

Thank you - much appreciated!