# CPU choice E5-2650 v4 vs E5-2630 v4



## trumee (Aug 3, 2016)

Hello,
I want to build a FreeBSD based NAS which run a lot of jails/bhye vm's. The server will also be used to run parallelized scientific code and video transcoding.

I have a choice of buying E5-2650 v4 or E5-2630 v4. The former has a TDP 105W while the latter has a lower TDP of 85W. If price was not an issue which is a better choice?


Thanks

Edit 1: Should be E5-2650 v4 instead of E5-2560 v4


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## Murph (Aug 3, 2016)

trumee said:


> I have a choice of buying E5-2560 v4 or E5-2630 v4. The former has a TDP 105W while the latter has a lower TDP of 85W. If price was not an issue which is a better choice?



It looks like you made a typo above, saying "E5-2560", but linking to the E5-2650.  I'm assuming you meant the latter.

If price is not an issue, and running cost is not an issue, the 2650 clearly should have the performance edge due to the larger cache.  Larger CPU cache is almost always better for compute performance, if all other factors are equal (e.g. technology generation, clock, bus performance, etc).

A quick scan of the Intel spec sheets says to me that the 2650 is pretty much the higher performance device in almost every regard (cache, bus speed, cores, threads, memory bandwidth, etc).  It has a slightly lower "turbo" clock, but that seems likely to be insignificant after all the other benefits.  It's not necessarily a huge difference in performance between them, but the 2650 clearly looks like the higher performance device, although both are essentially minor variants of the same processor.  Whether you will actually get sufficient benefit from the additional performance (to justify the extra cost), that's something only you can answer (but both science and video can be quite compute intensive, so the marginal benefit may be useful to you).

Intel's site lets you do an easy side by side comparison of them: http://ark.intel.com/compare/92981,91767

On a pedantic note, what you describe is most certainly not a NAS (network-attached storage).  It is a general purpose server providing both file storage and compute/processing services.  A true NAS only provides file (and maybe print) service, and nothing else; certainly not something that would run lots of jails/VMs.


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## SirDice (Aug 3, 2016)

For running VMs using bhyve (or any other hypervisor) the CPU is only part of it. The mainboard is just as important. Sticking a really good CPU on a crappy board wouldn't do you much good. Make sure the board supports VT-d. If you're going to put the machine somewhere in the attic or in a cupboard you'll probably want a board that supports IPMI too.


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## sizigee (Aug 3, 2016)

SirDice said:


> For running VMs using bhyve (or any other hypervisor) the CPU is only part of it. The mainboard is just as important. Sticking a really good CPU on a crappy board wouldn't do you much good. Make sure the board supports VT-d. If you're going to put the machine somewhere in the attic or in a cupboard you'll probably want a board that supports IPMI too.



^^ This I agree with... very important.


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## trumee (Aug 3, 2016)

I will be going with Supermicro X10DRi-T motherboard. This does have a ipmi and 10Gbe NIC for future proofing.

Is E5-2650 v4 still a better choice than E5-2640 v4?

E5-2650 v4 has a Tcase of 80C which is higher than E5-2630/2640 v4. So I can run it a little bit hotter as well?


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## Murph (Aug 3, 2016)

trumee said:


> Is E5-2650 v4 still a better choice than E5-2640 v4?



Intel's site lets you do a 3-way comparison as well (it may allow more than 3, if you have other models you want to add to it, just click the compare button on each spec sheet page):

http://ark.intel.com/compare/92984,92981,91767

The 2640 is a slightly faster (2.4 vs. 2.2GHz) 2630, by the looks of it.  So, if you have workloads that can't fully use the extra cores in the 2650, it might be slightly faster.  The 2650 is probably the fastest of them all, if your workload can make good use of it.  Intel's product numbering within a single generation / series is mostly higher numbers offer higher performance (although there are probably exceptions to that rule).



trumee said:


> E5-2650 v4 has a Tcase of 80C which is higher than E5-2630/2640 v4. So I can run it a little bit hotter as well?



Tcase of 80°C vs. 74°C should be almost entirely ignored in terms of choosing a CPU.  Firstly, the numbers are so close that they might as well be the same.  Secondly, those are maximum allowed temperature, so it's just a case of engineering your cooling properly (i.e. good quality thermal paste/gasket properly applied per manufacturer's recommendations, heat sink, heat sink fan, case fans, and good unobstructed airflow, etc).  Choose the CPUs on performance, then engineer appropriate power and cooling to support them.  Temperatures should only be a concern if you are trying to build a cool-running or passively cooled system; it's not something that should influence processor choice in a server (not on a high powered server, anyway), just something to be factored into the overall build of the system.

On any of those CPUs, if you are approaching Tcase under normal operational conditions, you have something badly wrong with the system's overall engineering / build.


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## Polyatomic (Aug 4, 2016)

The motherboard you linked to is a dual socket, so your getting two processors?
You mentioned:


trumee said:


> Hello,
> The server will also be used to run parallelized scientific code and video transcoding.


Wouldn't you want speed for that, how about _two_ of these:
http://ark.intel.com/products/92983/Intel-Xeon-Processor-E5-2637-v4-15M-Cache-3_50-GHz.
All apologies for being off topic abit wrt the two choices of processor.


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