Dear Ross,
Thanks for the reply Ross. Hum... I could use 4 GPUs in Amber 11 (prob.
without pear to pear) that's why I thought it was strange.
But anyway, I will use 2 x 2 GPU simulations for further simulations.
Thanks a lot for quick reply :-)
Best,
Asai
On 07/29/2015 11:31 PM, Ross Walker wrote:
> Hi Asai,
>
> This problem is normal. Please read http://ambermd.org/gpus/ for details. Specifically this section http://ambermd.org/gpus/#Running
>
> Specifically, if you have not purchased hardware designed to support 4 GPUs in parallel via 'peer to peer' then you will most likely be limited to a maximum of 2 GPUs per simulation.
>
> I would suggest running either 4 independent simulations, one on each GPU or running 2 x 2 GPU simulations on each pair of P2P capable GPUs. Likely this will be 0+1 and 2+3. But you can use the check_p2p code on the above website to check this for sure.
>
> All the best
> Ross
>
>> On Jul 28, 2015, at 11:35 PM, 浅井 賢 <suguruasai.gmail.com> wrote:
>>
>> Dear Amber user,
>>
>>
>> Hi, I'm facing some strange problem on using 4 GPUs with pmemd.cuda.MPI sometime so I wonder if someone can help me.
>> I am not really sure the minimum requirements for reproducing the situation but it occurs probably when I use pmemd.cuda.MPI to use two or more GPUs in a simulation.
>> The phenomenon is a sudden utilization drop, which you can see the screen shot below.
>>
>> http://gyazo.com/07564256c2b9a9f02277cc5d6170ba15
>>
>> It seems the simulation is slow but goes OK actually but I'm afraid physical problem on GPUs, and also it is so annoying.
>> While I have no idea what's going on, I don't know the word to search on internet.
>> So does anybody have any idea?
>>
>>
>> Thank you.
>>
>>
>> Asai
>>
>>
>> ATTACHEMENTS:
>>
>> md.out - mdout file of `pmemd.cuda.MPI`
>> nvidia-smi.txt - `$ nvidia-smi > nvidia-smi.txt`
>> <md.out><nvidia-smi.txt>_______________________________________________
>> AMBER mailing list
>> AMBER.ambermd.org
>> http://lists.ambermd.org/mailman/listinfo/amber
>
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Received on Fri Jul 31 2015 - 00:00:03 PDT
