v1.9.88.1 only detecting 2 of 8 cores

Started by Pyronious, April 28, 2008, 07:24:49 pm

Previous topic - Next topic

jo

Hi,

I think the problem is that what we use to detect the number of processors on XP perhaps doesn't tell us the correct number of cores, only the number of actual processors. So, for a machine which has 2 processors but 4 cores, it will only tell us that there are two processors available. It will also give different results if your processor(s) use HyperThreading. For Server 2003 up, including Vista, we do it another way which is accurate. There is another way to do it on XP but it is much more complicated.

Regards,

Jo

jo

Hi again,

I should add that if you're using Vista and getting the incorrect number of cores reported it would be very interesting to hear from you.

Regards,

Jo

Moose

Quote from: jo on May 02, 2008, 06:45:06 am
Hi again,

I should add that if you're using Vista and getting the incorrect number of cores reported it would be very interesting to hear from you.

Regards,

Jo


Hi Jo,

I was not experiencing any apparent issues with max cores set to 4, but after reading your post decided out of curiosity to see what times the other settings would yield. They look a off.

Intel quad core
Vista x64

Min   Max   Time   CPU usage
1      1       2:45   25%
1      2       1:34   75%
1      3       1:00   100%
1      4       0:47   100%

jo

Hi Moose,

Quote from: Moose on May 02, 2008, 04:04:14 pm
I was not experiencing any apparent issues with max cores set to 4, but after reading your post decided out of curiosity to see what times the other settings would yield. They look a off.


I think we may have crossed wires here. I'm talking about the number of logical processors reported on the splash screen and in the About box. That's the number TG2 uses to decide the maximum number of threads it will use, if the max threads setting is greater than the number of cores TG2 has detected. I'm not sure what you think I was talking about :-).

In any case, I don't really see a problem with your results. You're getting a good increase in performance each time you allow a new thread, so that's ok. I don't know that the CPU usage numbers are anything to worry about, threads don't necessarily run the whole time on the CPU/core they started on and they can bounce around a bit. It's up to the OS to decide where a thread runs, so your numbers might just be saying that the OS was bouncing the threads around 3 cores when running 2, and all the cores when running 3. I'm not really sure, but I don't think it matters too much.

Regards,

Jo

Oshyan

I imagine some of the optimizations we're doing now might also improve the expected utilization of CPU cores with 2 and 3 threads vs. 4 (you would expect 2 to use 50% for example). The important thing though, as Jo said, is there is still a decent speedup with more and more cores.

- Oshyan

Matt

According to MS documentation, the function I'm using should be available on the following:

Windows Vista, Windows XP Professional x64 Edition, or Windows XP SP3.
Windows Server 2008 or Windows Server 2003.

So XP with SP3 should be OK. However we've had reports that TG is not detecting all the cores on some Vista configurations, so I think there might be other reasons why it's not detecting properly.

If you are running any of the above versions of Windows and it's not detecting the correct number of cores, can you please run tgdcli.exe from the TG2 program folder and tell us what the first 5 lines say in the console window? (You can omit license information, of course.)

Matt
Just because milk is white doesn't mean that clouds are made of milk.

Matt

I was using some sample code from MSDN to count the number of cores. I'm looking again and it appears that MS have made some changes to the sample code which may help. Or perhaps I did something stupid when I first adapted it. Either way, I think I have an idea what the problem might be.

Matt
Just because milk is white doesn't mean that clouds are made of milk.

nikita

In case you still need it, I'm running XP Pro 64:
<<<### APP RUN STARTED ###>>>
Terragen 2 Technology Preview 3 (build 1.9.88.1)
Licensed to CrackedByAppzM4str83
Found 1 logical processors (cores).
AddClass: added class group (268611520 268611616)
//etc.


TG2 detects the number of cores correctly on my notebook. It runs XP Pro (32).

PS: ;)

nikita

When I'm booting XP 32 instead of XP 64, TG2 detects both cores.

lightning


rcallicotte

I'm showing only 1 core in xp64 and was showing 4 cores in xp32. 
So this is Disney World.  Can we live here?