I started my post there, it got moved to here. That hotfix (64 bit) didnt work for me. i got an error with AutoCAD LT when i try to run it after i renamed the two files and cut/paste the new files.
Quoc, the reason 'AutoCAD 2012 Performance Slowdown Hotfix' didn't work for your AutoCAD LT 2012 is because the hotfix was designed for all AutoCAD 2012 verticals. It wasn't intended for AutoCAD LT.
What may be causing the long delay in your drawing with 5000 layers is not so much the layers themselves, although that seems too unwieldly to be useful, but rather a large number of layer filters that are present in the drawing.
In a drawing with a significant number of objects, AutoCAD compares each object with each layer filter to determine if the object should be displayed and if so what color, lineweight, etc. it should use. With a larger number of layer filters, like a couple dozen for example, it takes a while to compare 5000 layers against all filters.
To test this, try making a copy of the drawing, then delete all the layer filters and see if performance improves drastically. If so, then try to reduce the number of unneeded layers and layer filters in the original.
In one such instance in a previous case, the customer found he only really needed 35 out of 5000 layers and only two or three layer filters. So he removed the excess. That change made a huge difference in performance.
We are having that problem with some computers in our office.
It gets worse during the day.
Problematic files are "exchange" files, which are edited by many operators. (everyone adding own layers)
When regenerating the file the computer uses only one of four cores. I thought that 64 bit LT should use alla cores..
Oddly the problem is only with 64bit software. Some older 32 bit machines handle files well.
Problematic computer is a new HP Z400, 8G, FX1800
Yes and no..
So if I've understood it right, there's no other solution for LT2012 than reduce the amount of layers in file and no software update for LT is available. Some day will?
The problem must be software based because 32 bit version with older computer can handle those file better = faster.