Yesterday night, I found something. My OS is win 98 (with Bryce 4, 1,4 ghz, 512 meg of RAM) While rendering, I usally open windows explorer and put Bryce on "background task" to prevent any hit on the keyboard to stop the render. It seams that rendertime is TWICE LONGER than Bryce in "front task" (excuse my english!!). Win98 seams to be really bad with multi task. Can you confirm it, is it the same with Win 2000?

I also have Win 98SE and Bryce 4.1, and maybe this is something that I have grossly overlooked...but I have never seen a "background task" function. Do you mean you just minimize it, or you JUST open window explorer over it, something like that? (just wondering) Either way, any other activity you do on your pc while you are rendering will have some kind of an effect on the rendering time, no matter how fast the cpu, how much ram, or on what OS. But, perhaps Windows 2000 is better at multi-task than 98, I'm not sure myself (probably is). But, I can make one suggestion, if you are going to do anything else while rendering, use the "render to disk" function. This way your video card only has to worry about windows explorer vs. constantly updating the Bryce window AND...windows explorer. By the way, I believe the only keyboard button that will stop your rendering is the Esc key. Maybe, if you can, try jockeying the keyboard on top of your monitor to prevent any accidental key smashing. (Wow...can I droll on without actually answering the original question, or what?) Agent Smith

Yes about minimizing (my english is far from perfect!). The "funny" thing is, with only Win98 and Bryce running, when I click on the tool bar: the speed of the Bryce's rendering statut bar decrease even if I do anything else. I forgot the "render to disk" option, I'm going to use it. Thanks Agent Smith.

When you minimize in Windows 98 any software and open a new one, windows will put more CPU for the software you are using and when finish doing the task will give Bryce the CPU power back. Its a little bit the same on W2k and Win XP but you have a better control over it for telling him real time process you want. But the best is what AgentSmith told about using render to disk. DenisG

Ahhhh. That render to disk option will come in handy for me, as well. (Also on Win98.) Thanks for that info, Agent Smith.

Before WinXP was available, I ran a formal performance test comparing OS performance. The test was done on one dual-CPU computer (P3-800(?),512Mb ram) booting to Win95, Win98, WinME, WinNT4 and Win2K. The task was to solve a large matrix with a mixed integer optimizer. This was not a rendering job...but it was a large, CPU-intensive "batch job" doing floating point calcs. The result? With one CPU removed, the OS made no difference (within 1%)! After plugging in the second CPU (not running parallel), NT and 2000 performance gained 10%...probably due to offloading OS tasks. Switching the optimizer to parallel mode for NT and 2000 nearly doubled the performance. Performance continued to gain when using CPU's available on the LAN. They tell me the new Windows versions are faster, but not on the number-crunching jobs we see. With luck, I'll find time to run an XP test in the future. The only other thing we have found is that Win95 and Win98 leak memory. So they must be rebooted daily...if they don't crash first. Also, we found Win2000Server to be more stable than WinNTServer. I'd like to add a Linux box to my home LAN and render my Rhino and Bryce models on it. Anyone tried this? Is there any reasonable software for Linux? How about parallel rendering across a LAN using mixed OS's (Win, Linux)? Zarth

Thanks to you guys!! From now on, I'm gonna change my rendering method.