WHIPTHREAD variable not working?

Hello,

I am trying to maximize the 2D drafting performance whilst running ACAD 2012. To that end, I have been playing around with the WHIPTHREAD variable, because when I have largish files, I find it annoying to have the regeneration hesitate when I zoom in or out in model space. Setting WHIPTHREAD to values other than "0" is supposed to allow ACAD to utilize more than one core/thread for regen and/or redraw functions (like zooming in or out in model space).

Okay, so I run Windows task manager while doing this, and I notice that the CPU usage for ACAD is never more than one core (or one thread, in the case of processors with hyperthreading turned on). I have tried this out on various machines, from my home system with a quad-core (non-hyperthreaded) i5-2500K, to the 4 core/8 thread Xeon workstation at the local community college's computer lab. Same result. Task Manager shows maximum 25% of CPU used for ACAD when running the i5, maximum 13% when running the Xeon with hyperthreading.

I have googled this to death and cannot find anything further than people recommending to set the WHIPTHREAD variable, what it is supposed to do, etc.

Has anyone else noticed their processor does not utilize more than one core/thread when WHIPTHREAD is set to 1, 2, or 3 - when regen/redraw occurs?

Is my task manager lying to me about cpu utilization (I tend not to think so, as I don't notice the zoom function getting any smoother/faster)?

I've found that AutoCAD just plain sucks when it comes to performance. It lags in panning and regens, no matter how beefy the computer is. You would think 2D shouldn't be that hard for AutoCAD to figure out.

I don't know the difference, but I work in Adobe products frequently and any vector based file(s) I'm working on has zero issues when I pan/zoom/etc, in performance or regenerating the objects.

I just don't know how much WHIPTHREAD actually works. Maybe for a previous era of computers and AutoCAD, but I've never found any noticeable differences in this particular variable.

The same files exhibit the same hesitation while panning and zooming whether I have my i5 at stock setttings, or overclocked to 5Ghz, so I think you're right - it doesn't matter how powerful a machine you have (maybe it mattered when the difference was between a 1.8 GHz processor and a 3.0 GHz processor?) Maybe the underlying code is still that unwieldy despite 2+ decades of development.

Plain old ACAD 2D only uses 1 core/thread, but the lone exception is supposed to be this WHIPTHREAD setting which Autodesk claims is supposed to allow the program to load up another core/thread when doing regeneration or redrawing of the model (like when zooming or panning around). According to my task manager, that is not happening, so I just wondered if I was crazy, or missing something, or other people notice this too.