ZBrushCentral

Auto Compact memory

ZBrush Artworks
#1

Just a question, but what is the Auto Compact Memory?

David

#2

When Z brush runs out of memory it writes some of what is in RAM to disk sort of like virtual memory, that’s because it is virtual memory. anyway in compact memory you can tell ZBrush how much real memory is has to work with. When it runs out it automatically will then write to disk.

So set compact memory to the amount that you have allocated for zbrush.

I think that if you set it to lower than what you have allocated then ZBrush will write to disk when it doesn’t have to.

Also you can tell when it is writing do disk by looking at the memory and virtual memory at the top of the ZBrush window. So if you find that ZB is writing to VM a lot then you can allocate more memory if you have it. Or if you need to then you can allocate as much as possible to ZB and don’t run any other programs if you are short of RAM. Remember writing to disk really slows down the program.

#3

Sorry, I’m very confused. Where do I tell ZBrush how much real memory is available? And why doesn’t it just get that information from the Windows OS? Or was that a Mac answer? :confused:

#4

Flycatcher,

I am uncertain what type of memory scheme ZBrush incorporates but basically it boils down to this: You have real physical memory and virtual memory (equivalent to scratch disk space in Photoshop). When ZBrush does its thing it stores all the relevant data etc to real memory. When real memory is full it then runs over into virtual memory. In the meanwhile ZBrush will begin to compact memory, that is it will clean up after itself and dump the uneeded stuff out of real memory. The level of real memory at which it does this is the compact setting. Thus when you set it to compact memory at 256 you are telling it to clean up after itself when it exceeds 256 Mb of ram.
This is what it is doing when you see the little bar go across the screen that reads “Compacting Mem”. This setting can be found in your preferences menu. And what Han has said is absolutely right. Allocate as much memory to the Comapct Memory setting as you can get away with to reduce the amount of time that it is writing to disk. It is not a Mac or a Windows thing. It is a ZBrush thing and Photoshop does a similar thing. That is what enables you to manipulate files that are much larger than what your Ram would normally allow.

#5

Thanks Mentat - somehow I almost missed this reply.

I understand the difference between the RAM memory and the virtual disk based memory that it uses when it runs out of the former. The bit that I’m finding confusing (other than that Z doesn’t simply get this info from the OS) is the phrase “the memory I’ve allocated to ZBrush”.

So far as I’m aware, I haven’t allocated any specific amount of memory to the program. Does this mean that if I have 256Mb of RAM, I should set the Preferences option to 256, or should it be some lower share of this memory pool? And if the latter, how do I determine the appropriate value?

Sorry to be so obtuse - put it down to advancing years. :wink:

#6

if you have a mac then you highlight the application icon and go to File :small_orange_diamond:GetInfo :small_orange_diamond:Memory

You would set the amount to be the maximum that you can afford bearing in mind that the OS needs a certain amount of ram. And keeping in mind what other programs you might want to run as well. If you don’t have a lot of ram you’d want to configure Z to have everything that the system doesn’t use and not to run anything else.

I believe that windoze is quite different.

#7

I set mine to about 2/3 of my available RAM. But that’s because I’m usually running several programs at once. If you only run ZBrush by itself, then you can certainly go with a higher value.

The higher the number you put in, the more of your computer’s RAM will be used before it starts compacting.

#8

thnx guys…I learned something new…great info

#9

For the anecdote :slight_smile:
Zbrush on a PC with Cyrix 166 with 32 MEG Ram + windows 95 must have 80 Megas free on the disk :slight_smile:
Under 80 on the disk it’s crashed :slight_smile: so have over 80 for enjoying paintings :slight_smile:
Pilou with very old machine :slight_smile:

#10

Thanks Aurick. I discovered the default was less than a third of the available RAM on my machine. As I normally only have Explorer running (for tutorials) while I’m running Z, I’ve upped this to 80% now - see how it goes! :+1:

#11

wow, that’s for the info! I hadn’t realized this. :smiley: