[Mesa-users] Regarding number of threads in M1

[ABHIJNAN KAR 20064]

Thanks for the reply!
Yes, Now I can see in the activity monitor that the binary run is having 16 threads currently! However, the question remains why changing the number of OpenMP thread is not reducing computation time significantly?(let's say changing number of thread from 8 to 16).

> On 26-Jan-2023, at 9:58 PM, RICHARD H D TOWNSEND <townsend at astro.wisc.edu> wrote:
> 
> Correction: the thread number *does* measure the number of OpenMP threads, but it also measures threads of other types. In any case, you should be looking at the thread count for star, not for Terminal.
> 
>> On Jan 26, 2023, at 10:26 AM, RICHARD H D TOWNSEND via Mesa-users <mesa-users at lists.mesastar.org> wrote:
>> 
>> The number of threads reported by Activity Monitor is not measuring the number of OpenMP threads. Likewise, the MESA executable (star) will show up as a separate entry under activity monitor — you shouldn’t be looking at Terminal.
>> 
>> 
>> 
>>> On Jan 26, 2023, at 10:21 AM, ABHIJNAN KAR 20064 <abhijnank20 at iiserbpr.ac.in> wrote:
>>> 
>>> Yeah,I am setting it in capital letters. I set it to 6/8/16/32 but the computation time is not changing significantly. So I am wondering about the number of threads in M1.Also supposedly there is no control over the number of threads terminal is using. Even after setting the variable to 16, in activity monitor it shows 6 threads are being used by terminal.
>>> 
>>> On Thu, 26 Jan 2023, 21:28 Evan Bauer, <evan.bauer.astro at gmail.com> wrote:
>>> Hi Abhijnan,
>>> 
>>> The environment variable that MESA uses to set the number of threads is OMP_NUM_THREADS (this is case sensitive, so make sure you're setting it with all capital letters). Is this the exact variable you are setting? Setting omp_number_of_threads will not get picked up by MESA.
>>> 
>>> Cheers,
>>> Evan
>>> 
>>>> On Jan 26, 2023, at 3:14 AM, ABHIJNAN KAR 20064 <abhijnank20 at iiserbpr.ac.in> wrote:
>>>> 
>>>> Also, another thing I noticed, even though I am setting the number of threads to 16,in the activity monitor it is showing that the terminal is only using 6 threads.
>>>> 
>>>>> On 26-Jan-2023, at 1:07 PM, ABHIJNAN KAR 20064 <abhijnank20 at iiserbpr.ac.in> wrote:
>>>>> 
>>>>> Thanks for the reply! I tested with various omp_number_of_threads. I set it to 6,8,16,32 but the computation time was more or less similar(for 287 steps).It took around 5 mins for 287 steps . The lowest time was 4.77 minutes with threads= 8. Setting the threads to 6 or 16 didn't improve computation time, rather it got a bit slow(by few seconds).
>>>>> 
>>>>>> On 26-Jan-2023, at 11:30 AM, Francis Timmes <fxt44 at mac.com> wrote:
>>>>>> 
>>>>>> do the experiment and say what you find!
>>>>>> 
>>>>>> the m1 pro has 10 cpu cores, two efficiency cores and eight high performance cores.
>>>>>> there is a base model with 8 cpu cores, two efficiency cores and six high performance cores.
>>>>>> another experiment to do is set the number of threads to the number of high performance cores,
>>>>>> as a check on the two efficiency cores slowing down a run.
>>>>>> 
>>>>>> fxt
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> On Jan 25, 2023, at 12:47 PM, ABHIJNAN KAR 20064 <abhijnank20 at iiserbpr.ac.in> wrote:
>>>>>>> 
>>>>>>> Hello users,
>>>>>>> I usually set omp_number_of_threads to 8 in my 8 core M1 macbook air.However, it seems that mesa run is slow on my machine using omp_numer_of_threads= 8.My question, can I set it to 16 ,as in general number_of_threads= 2* no of cores ?
>>>>>>> Regards,
>>>>>>> Abhijnan Kar(He/his/him)
>>>>>>> BS-MS,IISER Berhampur
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> mesa-users at lists.mesastar.org
>>>>>>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>>>>>> 
>>>>>> 
>>>>> 
>>>>> Regards,
>>>>> Abhijnan Kar(He/his/him)
>>>>> BS-MS,IISER Berhampur
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> Regards,
>>>> Abhijnan Kar(He/his/him)
>>>> BS-MS,IISER Berhampur
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> mesa-users at lists.mesastar.org
>>>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>> 
>>> 
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>> 
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> 

Regards,
Abhijnan Kar(He/his/him)
BS-MS,IISER Berhampur






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