Re: AW: Xeon vs i7 and ECC vs SDRAM

From: Gianluca Interlandi (
Date: Wed Jun 25 2014 - 01:14:48 CDT

Dear Norman,

Thanks for your explanations. I think that I am leaning towards the Xeon
server. I am still undecided though about the video card. Lenovo gives me
only choices of NVIDIA quadro for their Thinkstation, but I'm not sure it
is worth it to spend $700 more for the K4000 (or $400 for K2000). If I'm
just using it for visualization (no CUDA computing) does it bring any
advantage to have anything faster than e.g., a quadro K600? Later on, if I
want to do any CUDA computing I can always add an inexpensive GeForce GTX

The alternative is to replace the quadro card that comes with the
Thinkstation with a higher end GeForce GTX right from the beginning, but
I'm not sure whether it is worth it, if I'm only using it for VMD
visualization (max 200,000 atoms).



On Wed, 25 Jun 2014, Norman Geist wrote:

> BTW. all modern RAM is SD, ECC enabled or not, that?s the history:
> SRAM = Static RAM : +very fast -very expensive (used eg. in Caches)
> DRAM = Dynamic RAM : -slower than SRAM (CPU must wait for refreshes) +much
> cheaper
> SDRAM = Synchronous DRAM +faster than DRAM (CPU don't need to wait for
> refreshes, as synchronized) +still cheaper
> DDR-SDRAM = Double Data Rate SDRAM ...
> Regarding your question, Xeon is a workstation/server CPU while i7 is a
> consumer CPU. Therefore Xeon is more expensive but also more reliable. The
> ECC feature does improve that even more. A Xeon won't wonder about 24/7 use,
> I wouldn't put my shirt on the i7 in this regards. In case of performance, I
> think there's no major difference.
> BUT, if you want to run NAMD and VMD on this machine, why not taking more
> care about getting a strong Nvidia GPU?
> Norman Geist.
>> -----Ursprüngliche Nachricht-----
>> Von: [] Im
>> Auftrag von Gianluca Interlandi
>> Gesendet: Mittwoch, 25. Juni 2014 03:03
>> An: NAMD list
>> Betreff: namd-l: Xeon vs i7 and ECC vs SDRAM
>> Dear NAMD users,
>> I need to purchase a new workstation for trajectory analysis, i.e.,
>> using
>> VMD and NAMD. I am leaning towards Lenovo but I am undecided between a
>> Thinkcentre and a Thinkstation. The former comes with i7-4770 and non-
>> ECC
>> memory, the latter with e.g., Xeon E5-1620 v2 and ECC memory.
>> The first question is: does Xeon (in particular the larger cache) bring
>> any advantage for running VMD or NAMD? Is it generally true that Xeon
>> run
>> cooler and thus more stable than i7?
>> The second question is: is it worth to pay for ECC memory when I plan
>> to
>> have a maximum of 16 GB? I know that there is a lot of debate about
>> this.
>> Since I plan to run the server 24/7 my main concern is stability.
>> The last question is: does it make sense to have a Xeon CPU with non-
>> ECC
>> memory or would it be a waste? I have read that for example SDRAM is
>> the
>> safest non-ECC memory and it would be a lot cheaper.
>> I would appreciate any opinions on this.
>> Thanks in advance!
>> Gianluca
>> -----------------------------------------------------
>> Gianluca Interlandi, PhD
>> +1 (206) 685 4435
>> Research Scientist at the Department of Bioengineering
>> at the University of Washington, Seattle WA U.S.A.
>> -----------------------------------------------------
> ---
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Gianluca Interlandi, PhD
                     +1 (206) 685 4435

Research Scientist at the Department of Bioengineering
at the University of Washington, Seattle WA U.S.A.

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