ZBrushCentral

Zbrush always crashing due to ram!!

ZBrush Usage Questions
#1

So I’ve just upgraded to 24gb of high quality ram and still Zbrush continuously crashes over and over when doing simple tasks like baking out a displacement map or projecting a 1 mesh onto another. I have set the RAM slider to the max in preferences/mem but it doesn’t seem to make a bit of difference. Surely with 24gb of ram I shouldn’t be running into these issues…

anyone else have these same problem?

#2

Mac or PC? Shouldn’t matter…ZBrush is still 32 bit. It can’t use all that ram; 4 GB is all, unless I’m mistaken.

#3

Doug’s right.

ZBrush can use no more than 4GB ram on a 64bit system currently.

Full 64bit support is meant to be in the works for ZB 5. Let’s hope this arrives sooner rather than later!

#4

Ah of course, that would explain it. Maybe my mesh just has too many polys and cant handle it.

#5

If you have no problems with less complex meshes then that would be the problem. If it’s happening with any mesh, it would be a permissions problem that prevents virtual memory from being written. That doesn’t sound like it’s the case, though.

Some things that can get you in trouble:


  • A really large undo history. You can delete that or reduce its size.
  • Lots of sculpting layers. Remember that each of these is essentially a morph target, making it a copy of your model. So if you have a SubTool with 15 million polys and 6 layers that ends up being over 100 million polys!
  • Too many polys per SubTool. You’ll get better results splitting the model into more SubTools wherever possible.
  • A heavily fragmented system drive can prevent ZBrush from utilizing virtual memory efficiently even though there’s lots of disk space.

Also keep in mind that saving as a ZPR saves a lot of data that you may or may not need. It’s the most convenient, but it will save a lot more than just the model itself. That can add up to a lot of memory resources depending on what you’ve been doing. A ZTL saves just the model and any applied maps, which is more memory efficient. It also doesn’t save the Undo History.

Finally, a 32-bit application is limited to 4 GB files. In practice, the upper limit will usually be a bit lower than that. If your file starts pushing 3 GB in size, it’s high time to be looking for ways to optimize it.

I hope that helps!