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timk September 23, 2012 03:54

New "off the shelf" computer specifications - any good?
Hello. I am currently specifying new computer. I am looking at a mid-range machine for initially developing some simple models fast in ANSYS (14.0) and then developing some more interesting models, involving more complex 3D flow arrangements, in a few months.

I am limited to a machine that can be bought easily “off-the shelf”.
Thus far and looking at the ANSYS website I have found the HP Z820 workstation to be the most suitable machine.

And have selected the following technical specifications:

Operating system Windows® 7 Professional 64
Processor Intel® Xeon® Processor E5-2690, 2.9 GHz, 20 MB cache, 1600 MHz memory, Eight-core
Standard memory 64 GB 1600 MHz DDR3 ECC
Memory slots 16 DIMM
Internal drive (2) 2.5-inch SATA solid state drives: 300 GB, 1.8 TB max (configure for mirroring on RAID)
Optical drive SATA SuperMulti DVD+/-RW
Graphics AMD FirePro V7900 2GB GFX
Drive Bays Four 3.5"
Network interface 10/100/1000
Storage controller Two Integrated SATA 6.0 Gb/s; Four Integrated SATA 3.0 Gb/s; Integrated LSI SAS 2308 Controller; Eight LSI MegaRAID® 9260-8i SAS 6Gb/s ROC RAID Card and iBBU08 Battery Backup Unit

What do you guys think, what would you expect the main bottleneck(s) to be?

Cheers for your help and any suggestions,

scipy September 23, 2012 19:31

It's only worth buying if it's gonna be a dual cpu system (and even then a 2687W is faster, but both are not worth the money over the E5-2670).

However, if you're after a single CPU system then for 4x less money you should buy a i7-3930K desktop cpu. Yes, it has 2 cores less but it's ~500 USD compared to ~2000 USD Xeons, and it will be only slightly slower (or might not even be slower). You can make the i7-3930K work with unbuffered memory up to 2133 MHz (while most server motherboards create problems with anything faster than 1333/1600), and let's not forget that you can easily overclock it to 4.5 GHz - so even with "only" 6 cores, it might be faster than an 8 core Xeon (especially since RAM is a large bottleneck and i7 will work with much faster RAM).

If you are not willing to put together your own pc out of components (or even find them/make a list), I (or someone else) can do it for you and any shop will put the PC together and install Windows for you. There is literally no upside to buying from Dell/HP/etc. Their systems cost a lot more compared to what you can buy in components and generally underperform too.

Even if you decide to buy a dual cpu system, a better system can be put together from "gaming" hardware than can be offered by large companies.. Ask away if you'd like more information/options. It might help if you listed your available budget. :)

timk September 27, 2012 03:57

Hi Scipy,

Thanks for your response. I completely agree that buying off the self from Dell/HP etc is not at all cost effective. A much better (and cheaper) machine can be easily constructed from parts. But mine is not to reason why in this case.

I need to spec a more expensive “off-the-shelf" machine. approx 3K buget.

It is only the components that are easily avaliable with that machine that I can sadly select. Thanks.


evcelica September 30, 2012 11:25

If you are using cfx then you are wasting money on the 8 core, as your bottleneck will be memory bandwidth, not cpu.

timk October 8, 2012 08:34

Thanks evcelica - really useful link!

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