WHIPTHREAD variable in AutoCAD.

[ReMark]

The WHIPTHREAD variable controls the way AutoCAD uses the second processor (or core) in a multi-processor computer for display operations.

• 0 - use only a single processor (default)
• 1 - regen done on multiple CPUs
• 2 - redraw done on multiple CPUs
• 3 - both regens and redraws done on multiple CPUs

[S-8-N]

Okay so I found this variable and told everyone in the lab about it and they seem to be having the same problem I am now. AutoCAD freezes up / locks up comes up with the send a report to Autodesk box and then needs to be shut down, every few seconds to every few minutes. One time for me it went all pixalated and it happened on anther machine also. We have brand new computers (less than 3 months) running 8 cores, windows 7, AutoCAD 2011. I set this to 3 and it seemed to speed things up, like changing from one layout to another but that doesn't out way the shutting down part. Is this varialbe bugged/not working, or am I doing something wrong? Maybe something with Windows that is messing it up. We do have multipule appications (e-mail, internet, ect.) open at one time. Any help would be great THANK YOU!

[SLW210]

I have WHIPTHREAD = 3 and no problems. I have email, internet, windows explorer etc.

[ReMark]

WHIPTHREAD set to 3 here and no problems either.

I doubt that it is a bug in the command.

[SLW210]

Are you getting any error messages? Try checking the event viewer right after a crash.

[ReMark]

Home system > AutoCAD 2011 > WHIPTHREAD = 3. Running Win7 Ultimate 64-bit.

Work system > AutoCAD 2012 > WHIPTHREAD = 3. Running Win7 Pro 64-bit.

No problems on either system.

[driftingsun3]

I am running AutoCAD 2012 and Win7 Pro 64-bit; I don't actually notice a difference whatever WHIPTHREAD is set to. I have tried this out on various drawings, one which is ~17 MB. I select everything and zoom in and out rapidly. It seems to zoom smoothly whether I have the variable set to 0 or 3. The other thing I noticed is that ACAD doesn't use more than one core with the variable set to "3". In the Resource Monitor section of the Windows Task Manager, it shows AutoCAD using maximum 13% of the cpu (I am running an i7-2600K, 4core/8threads) whatever WHIPTHREAD is set to. Shouldn't the CPU usage go beyond 13% if I have WHIPTHREAD set to 3?