From: Francesco Pietra (chiendarret_at_gmail.com)
Date: Mon May 28 2012 - 11:03:43 CDT
Forwarded to the list, too, which I forgot previously
francesco pietra
On Mon, May 28, 2012 at 5:27 PM, Francesco Pietra <chiendarret_at_gmail.com> wrote:
> On Mon, May 28, 2012 at 12:35 PM, Axel Kohlmeyer <akohlmey_at_gmail.com> wrote:
>> On Mon, May 28, 2012 at 4:53 AM, Francesco Pietra <chiendarret_at_gmail.com> wrote:
>>> Hello:
>>> I am using NAMD on a consumer motherboard with two GTX-580 and one AMD
>>> Phenom II 1075T (six logical CPUs).
>>>
>>> I wonder whether NAMD code can run on three GTX-580 with the same AMD
>>> cpu above (providing the required two logical CPUs per GPU board). If
>>> so, I would also have to change the motherboard. I am considering
>>
>> this has nothing to do with NAMD. if you can stick in
>> the GPUs, you can use them with CUDA.
>>
>> however, whether you'll get good performance
>> out of it is a different question. performance depends
>> not only on the capability of the GPU but also
>> on the available bandwidth on the PCIe slots
>> (are all of them *real* 16x PCIe 2.x?) and the
>> memory bandwidth available to the CPUs.
>> because of those issues, performance will also
>> depend on the size of the problem that you'll
>> be running. not easy to tell up front,
>
> When referring to NAMD, I wanted to imply (badly, I admit) performance
> boost by the third GPU.
>
> The 990FXA-GD80 PCI specification is described by the manufacturer as follows
>
> -- PCI Express slots version: 2.0.
>
> -- PCI slots: 1.
>
> -- PCI express x1 slots: 1.
>
> -- PCI express x16 slots: 4.
>
> Whether these are real x16 2.x, or not, is beyond my understanding. I
> can only compare with the corresponding description for the mainboard
> I am currently using: GA-890FXA-UD5:
>
> 2 x PCI Express x16, running at x16 (PCIEX16_1, PCIEX16_2).
>
> 1 x PCI Express x16 slot, running at x8 (PCIEX8).
>
> 1 x PCI Express x16 slot, running at x4 (PCIEX4).
>
> 2 x PCI Express x1 slots.
> (All PCI Express slots conform to the PCI Express 2.0)
>
> 1 x PCI slot.
>
> With this latter mainboard, adding a second GTX-580 gave the expected
> acceleration. Data for PCIs of the two mainboards being comparable, I
> would expect that a third GTX-580 on the 990.. motherboard should play
> well its job. Is it this naive extrapolaion a sound one?
>
> Thanks indeed for further advice
>
> francesco pietra
>
>
>
>
>
>
>
>
>
>>
>> axel.
>>
>>> MSI MB 990XA-GD80 AM3 SB950 4DDRIII PCI-E ESATA SATA III ATX
>>>
>>> which can host three GTX-580.
>>>
>>> Thanks for advice
>>>
>>> francesco pietra
>>>
>>
>>
>>
>> --
>> Dr. Axel Kohlmeyer
>> akohlmey_at_gmail.com http://goo.gl/1wk0
>>
>> College of Science and Technology
>> Temple University, Philadelphia PA, USA.
This archive was generated by hypermail 2.1.6 : Tue Dec 31 2013 - 23:22:01 CST