Hi Burr, unfortunately the way that most of these calculations work it is not really possible to estimate before-hand how long they are going to take.

A lot of the calculations depend on the shapes of the objects involved, like when you do a boolean if the shapes intersect along a surface that has a lot of wiggly bumps in it, it will take longer to calculate that intersection in that area.

But there isn't any quick way to tell if the intersection is in a wiggly spot other than to actually intersect it.

Many of the mechanisms for calculating things are like this, where they start with a kind of rough answer and then keep on refining it until the answer is good enough. These mechanisms don't know how many steps it will take before hand, they keep going until the final answer is at a good enough level of accuracy.

It's not the same thing as something like a file download where you know you have x number of bytes and a y download speed, stuff like that can be estimated a lot better.

- Michael

Thanks, I supose I'll learn by my file size and operation to have my own estimate!

Hi Burr, yeah, that's another factor - if all of your system memory gets filled up, then Windows will start "swapping" chunks of it to your hard disk to free up some more memory to do additional work.

Once that starts happening things suddenly slow down by a huge factor, since the hard disk is far slower than memory.

It definitely helps a lot to have quite a bit of RAM installed on your system to avoid this. For example if your system has 512MB or less of system RAM and you want to work with larger files, it would definitely work a lot more smoothly if you got your machine upgraded to have more RAM. That tends to be the #1 kind of system upgrade to make things go more smoothly and it usually is not very expensive also.

- Michael