2nd CPU not recognized

[msiebold]

I just added a second processor to a workstation MB. Pixinsight will see and fully load the first processor, but leaves the second one at 0% load. I'm using a dual e5-2696v4 setup, so I should have 44 cores and 88 logical processors available. Pixinsight is only recognizing 44. I have been using both resource monitor and corsair link to verify that one of the processors isn't being used. Also, I've seen no performance boost since adding the second cpu.

I have of course reinstalled the program and reset the configuration data.

I was hoping that I might get some help, or find out if this is a bug in the current version of PI.

Version 01.08.05.1235

Thanks for your help,
Michael Siebold

[pfile]

good god 

are you sure prime95 or whatnot is seeing the 2nd cpu? i wonder if there is some kind of bios setting when you get into these insane number of cores?

you might be the first person to try running PI on so many cores... in the global settings, under Parallel Processing and Threads, that by default is probably set to "allow using all processors and threads", apparently setting the # of processors to some very large number. i guess it might be interesting to uncheck that and put 88 in the corresponding field and see what happens.

rob

[msiebold]

Well, I know that I have other code that I have written that will fully use both processors (and roughly doubles in speed since I added the second CPU), so I doubt that it's a bios setting.

Thanks for the idea! But I just tried the set manually to 88 cores idea and it didn't do the trick.

It seems like PI just doesn't see the second processor at all. I realize that this is an odd system, but I can't be the only dual CPU person out there...

[pfile]

juan would have to answer, if he sees this. i know he has been busy with family issues.

i guess although from 10,000 feet you would expect some OS abstraction to just say "i have 88 threads available", i guess it is not presented to the application that way. probably not that many people have dual socket motherboards, at least in the hobbyist community.

rob

[msiebold]

Totally understand family issues impacting things. Having some of those here, too... This is my first dual socket WS, so I'm new to these settings. All I know is that I have other programs that do utilize all cores, so I suspect that the hardware is recognized by the OS. Again, I don't know all that much about this level of parallelism. I'm just hoping I get to use it fully for PI, too. I'm trying some large integrations (~100 images per channel LRGBHa) and having 44 logical processors is nice enough, I'm really hoping to see what 88 can do.

[Juan Conejero]

Hi Michael,

This is a bug in current Windows versions of PixInsight. To learn the number of logical processors available, the PixInsight core application currently calls the GetSystemInfo Windows API function. This works for single-processor systems, but is incorrect on multiprocessor machines because it only retrieves the number of cores available in the current NUMA node. The correct API that must be used in these cases is GetLogicalProcessorInformation. It must be pointed out that this problem does not affect Linux, FreeBSD and macOS version of PixInsight.

Thank you for discovering this problem. I'm working on a new version of PixInsight right now, and will try to get this issue fixed in the next release. Unfortunately, there is no workaround to this bug. Sorry for the inconvenience.

[msiebold]

Makes perfect sense to me! I may try running a separate linux drive in the meantime. Thanks for your help!

Michael