Intel® Hyper-Threading Technology conflicts with LabVIEW utilities (VISA, Scope GUI, IO Trace...)

[SJ_Buddy]

I would like to share a pretty hard-to-troubleshoot issue we are experiencing for the last few months.

Our company used to get DELL T5500 for our engineers. The PCs work just fine with all LabVIEW utilities. But DELL has discontinued T5500 series and replace them with T5600. I got one of them few months ago and after installing LabVIEW, I tried to run VISA console via MAX. It immediately crashes MAX and destroy MAX database. After that I try to run other utilities like NI IO Trace, VISA Interactive Control, Scope Soft Front Panel, ... All of then crashed. I am running 64-bit Windows 7  + 64-bit LabVIEW. And we know that most of NI Utilities are 32-bit.

After a lot of frustration I went down to researching the computer BIOS level. And try to side-by-side compare with T5500. T5600 has much newer CPU and has  lot more performance enhancement features. I tried to turn of/on one by one to see if any affect LabVIEW utilities. To my surprise I found that Intel® Hyper-Threading Technology (Intel® HT Technology) is the sinner. After turning it off all LabVIEW utilities start to work just fine. All T5600s are shipped with this feature enabled by default.

We know that DELL Precision PCs are almost industry standard for all engineering department. I think in the next few years a lot of people will be hit by this issue. I already notified NI and DELL R&D so they can find a good solution. But I just would like to make this issue Google-searchable so that anybody see this issue may get some help.

Give me any feedback if you encountered the same problem.

Thanks,

[Zach J]

Hi SJ_Buddy,

Thank you for making this public knowledge on the forums.  It looks like one of our Applications Engineers is helping this issue get to R&D for analysis.  Until a permanent fix is released, disabling Hyperthreading in the BIOS sounds like a good workaround for users of the T5600.

[TroyK]

Nice find, thanks for sharing.

I wonder if this is related to other issues people have been experiencing with VISA crashing etc in the past?

For example:

VISA Enable Event dumps LabVIEW memory onto serial port

Perhaps a preexisting problem is just now more apparent because it is causing immediate crashes?

[Zach J]

Hi TroyK,

Have you tried disabling Hyperthreading in BIOS to see if the error you are encountering goes away?  That would be a good way to check and see if this issue is related to yours.

[TroyK]

Perhaps I should have done some testing before posting. I just tried it on my new computer which has a quad core i5 (no hyperthreading) and the bug I was referring to is still there.

If there is already a memory leak/corruption bug existing in the VISA driver it may be that hyper-threading is merely exacerbating the problem.

[ejkaiser]

Hi,

I was struggling for quite a long time with a large application that exhibited the following problems:

- The application stalls unpredictably after some time, sometimes a minute, sometimes hours. After clicking into the GUI it starts working again. This repeats in an unpredictable way. Competitive activities on the computer seemed to increase the stalling-frequency.

- Sound Input VI stops unpredictably and has to be restarted.

I really was considering to give up LV and turn to conventional programming.

For the moment it looks like disabling Hyperthreading in the BIOS cures the issue. It is a modern ASUS workstation board with 4-core i7 CPU runing under Win7 64 bit and LV2012.

I hope this is a permanent cure. I don't benefit from Hyperthreading because my applications are massively floating point dominated.

If the issue comes back I will be reporting here.

Cheers

Edgar

[ejkaiser]

Hi,

seems disabling the Hyperthreading really improved the situation very significantly. But once in a while, programs still stop, particularly in the Development system. It seems to be less in compiled programs.

So this is not yet really satifactory. And having to explain to the customers they have to disable Hyperthreading in their brandnew super-duper multicore machines is a bit cumbersome.

So, I find this should be a high-priority issue to NI and I would really like to hear what they are planning to do about it.

Cheers

Edgar

[ejkaiser]

So, today now complete frustration. Same problem as before even with deactivated Hyperthreading. I will have to look for a different programming system.

[altenbach]

This means that you were on a witch hunt and hyperthreading is not the problem. (I always had doubts).

The original thread was about crashes in the visa console, but your problems seem to be much more generic:

"- The application stalls unpredictably after some time, sometimes a minute, sometimes hours. After clicking into the GUI it starts working again. This repeats in an unpredictable way. Competitive activities on the computer seemed to increase the stalling-frequency.

- Sound Input VI stops unpredictably and has to be restarted."

Are you sure you don't have a general code issues such as race conditions or deadlocks. Maybe you should start a new thread and show us a simplified version of your program that still demonstrates the problem. If there are race conditions, moving to a different CPU can cause slight changes in execution order, exposing them.

Did you repair the LabVIEW and driver installation? What are the power settings of the computer? Did you update other drivers (such as video, power management, etc)

What is the exact CPU you are using? What third party utilities and security software is running on your PC?

[LindyHop]

Hello ejkaiser, 

Please create a new thread for your topic. This will allow your issue to be seen as a recent post as opposed to showing up in a thread from six months ago. Feel free to link to this thread, but posting a new thread will give your issue much greater visibility.