Intel i7 processor with hyper-threading (only every second core is used)

[ghighuphu]

Dear users,

the "CPU Information.vi" gives me the following output (see "CPU Information.png"). When I run a Labview vi, only four cores are used (see "CPU usage.png"). I believe that my processor has 4 physical cores and a hyper-threading feature: http://ark.intel.com/products/48500/Intel-Core-i7-880-Processor-8M-Cache-3_06-GHz

Do you have any idea how to use also the other virtual cores as well, please?

Kind regards,

M

[Yamaeda]

Are you running a parallell loop? Check your loop setup.
/Y

[ghighuphu]

Tha "parallel" option for for-loops is enabled on multiple places within my program.

[ghighuphu]

In "CPU usage.png" I can swipe over the green area and it says all over it "LabVIEW" (with about 12% utilization). The red area are system applications.

[crossrulz]

Can you post your VI?  Otherwise we are totally shooting in the dark.

[ghighuphu]

Unfortunatelly, I am not allowed and not able to post any of my code (besides, they are dependent on my local data). I am trying to assemble a vi for testing a multi-core processor PC. (any help or hint to a page with example is appreciated). So far I assembled a few for-loops but they all run too quick, so I cannot take any meaningful snapshot.

[altenbach]

There are plenty of ways to use 100% of all CPU cores but there are also plenty of ways to get less than 100%. There can be many reasons for lower utilization.

Is there shared code (e.g. non-reentrant subVIs). Is the data in processed in large chunks or does each code nibble on scalars? Is more data processed than fits in the CPU cache? Is it all pure math or is there synchronous code (e.g. lots of property nodes). Does the code operate mostly "in place" or are there constanty new memory allocations?

 Can you explain exactly what the program does?

[ghighuphu]

Thank you for your suggestions, dear all. Let's talk about an existing valid example. I read the [link removed]  article, and afterwards I found the "PI Day (LV 2012).zip" at https://forums.ni.com/t5/Example-Code/%CF%80-Pi-Day/ta-p/3500611 Next I've ran the "4 Calculate N Digits of Pi.vi" with N set to 10000 (ten thousand). The result was, that only four cores out of eight were engaged. Do you get similar or different results please? KR, M

[altenbach]

You only have four real cores. What else do you expect?

[altenbach]

If you turn off parallelization, how much slower is it?