ZBrushCentral

Answered: How important is Processor speed?

ZBrush Usage Questions
#1

hey all-

so, the wife is tired of me monopolizing the computer with zbrush and i have to get a dedicated machine for my workspace.

i’m currently using Zbrush 4, with a mac mini that has 8gb or ram (more than i need, i know) and the processor is a 2.4 ghz core 2 duo.
zbrush seems to run fine on this machine, though it does kinda “chug” along at times, but i have no real basis for comparison.

at first glance, i was thinking of just getting another mac mini, maybe bumping up to the 2.66 ghz processor…
however, the iMacs can be had with either the intel i3 3.2 ghz or the quad core i5 2.8 ghz chips.

so i’m left to wonder- will the mini with the 2.66 run noticeably slower than either of the iMacs when you run Zbrush?

thanks to all who chime in!

#2

Your CPU mostly affects two things:

:small_orange_diamond: How smoothly ZBrush interacts with the visible mesh while you’re actively sculpting it.
:small_orange_diamond: How quickly ZBrush renders an image.

If you have a weak processor, the first is easily countered. Simply break the model into more SubTools or hide the parts of the mesh that you’re not currently editing.

Also, now that we’re in the day of multi-core CPU’s the processor speed is actually not quite as important as it used to be. (This is why manufacturers keep pushing more cores rather than higher GHz.) Given two processors that cost the same money, go with the one that has more cores rather than higher speed.

#3

thanks, Aurick.

i think that about tears it for me, then.
i’d prefer as much speed as possible, so i’m thinking one of the imac quad core variants.
…and given the 2 examples you pointed out are exactly where i notice my slowdown, there ya have it.
thanks again!

#4

aurick- when i hide parts of my mesh it seems to slow it down more? when rotating the mesh it doesnt seem to step down to a lower subdivision when parts are hidden, whereas normally it does… is there an option to turn this on?

#5

RAM comes into play when you’re hiding and unhiding the mesh as well as when stepping between subdivision levels. So if your system is low on RAM you will see performance hits while doing those tasks. After ZBrush has finished compacting memory you should then be able to sculpt on a partially hidden mesh more smoothly than you could on a fully visible mesh.

As for the mesh displaying lower resolution when you rotate it, that’s governed by Preferences>Performance>QTransThreshold. This slider is in millions of polygons. Anything over that number of polys will cause the mesh to drop down a level when rotating. This means that lower values for this slider improve performance. However, this function does not occur when a mesh is partially hidden.

#6

aurick - Does this mean that you would rather have the AMD Phenom II (slower 6 core variant) compared to the i7-2600k (ridiculously fast 4 core)? I am building a new desktop in the next couple of months and want a machine that will be the best for zbrush, 3ds max, and HD video editing. Thanks

#7

On most modern processors each core is capable of executing two threads simultaneously. So a four core processor will run 8 threads while a six core processor will run 12.

In a program that does not multithread, faster speed is more important because the program will only end up running one process. However, with a program like ZBrush that does support multithreading across multiple cores the additional threads means that ZBrush is able to process data much more efficiently and give you better overall performance with processor-intensive tasks.