I ran the multithreading test and it said an increase of 200+ I think.
SYSTEM:
Intel Core i7-920 processor (8MB L3 Cache 2.66GHz) Integrated 7.1 Channel Audio
8GB DDR3 SDRAM at 1066MHz
Nvidia GeForce GTS 240 - 1 gig onboard memory
ATI 500GB Serial ATA 2 Hard Drive 7200 RPM
Windows 7 Ultimate, 64bit, English
So what should I set my mem settings to and how many undos etc
TIA
single thread timer = 3.58
muli thread timer = 1.216
Multithreading performance = 294%
Multithreading IS recomended for this system
OK how do I set up for mulithreading?
Hi
In ZBrush 3.5R3 usage of multiple CPU cores is most likely already enabled. As far as I know Preferences > Performance > MultiDraw is the only switch you need enabled to take advantage of multiple CPUs. In my experience Preferences > Performance > MultiThreaded Steps should be left at 6. Lower than that will decrease performance, as will anything higher than 7. But feel free to experiment.
As for memory settings I would leave them at the default especially the Undo setting. ZBrush will always try to reserve as many undos as there is available memory to do so. A higher value will just force the program to store undos when you are running low on resources for other functions.
As you have a 64 bit OS and 8 Gigs of ram you could increase Preferences > Performance > Compact Mem to the max of 4096 but the difference will be neglible, IMO, compared to previous version of ZBrush. The newer versions of ZBrush (3 and on) are intelligent enough to stop compacting memory to disk when the cursor is moved, in other words it only compacts during inactivity. Of course if ZBrush has to compact memory to perform the next operation it will do so regardless of your Compact Mem setting.
I prefer that Zbrush compacts memory fairly often ( the default ) so while I check a reference picture or browse the web it is more responsive when i return. Well that is how I look at it.
Preferences > Mem > MaxPolyPerMesh and HD Preview MaxPoly are settings I would only change when the need arises. For example if your MaxPolyPerMesh say 20.5 (million polygons) and you need 23 to subdivide once more, then go for it and change the value. But remember to save beforehand 
Thanks TVeyes:)
I started with 8 gigs of ram and zbrush defaults the max poly count to 21.6 million. When I added another 8 gigs of ram it didnt change this value. If I increase the max poly count and subdiv higher the program becomes fairly unstable (though at 40 million it didnt crash until i actually tried to sculpt). Watching the memory usage in the Task Manager I notice that it doesnt want to use more than 5.25 gigs of mem even though there are another 10 available.
Anyone know why this is or how to get zbrush to utilize more of the available ram?
Running on windows 7
16 gigs ram
2 xeon w5580s
nvidia quattro 5800
thanks
ZBrush is a 32-bit application. This means that it can never use more than 4 GB of RAM. On a 32-bit OS it’s limited by Windows to 2 GB. On a 64-bit OS it can use 4 GB. Anything that your system might have beyond that will be used by any other applications you might have running.
When ZBrush might receive a 64-bit version in the future is something that I cannot answer.