CPU usage

I'm a little rusty to the inner workings of SL as I haven't been as active in awhile, but I noticed today that the SL app newview.exe seemed to be using all available CPU time as long as I was connected. Is there any particular reason for this? I have a 1.8ghz machine with 512mb of physical DDR and 4gb of virtual ram. I watched it over about 20 minutes in a relatively quiet sim with only 1 other person in it and I was still using 100% of my cpu.

The reason I ask is that I thought that SL didn't take up too much CPU time and I had my fans all the way down on my watercooled system to keep the noise low. I glanced at my Temp readings and it was over 50C. I'm used to my system being lower then 42C and I had to turn my fans back up.

SL does a lot of work on the CPU to reduce the load on the graphics card; the CPU is working hard to give you as high of a framerate as possible. However, I don't think it is designed to throttle itself down, so even if you were running at 100 FPS, it woudn't drop to 75 just to free up the CPU for other stuff.

Incidentally (for anyone who didn't already know), when it comes to low FPS in SL, the bottleneck is not necessarily the video card. When the CPU is doing a lot of work then anything that helps it do its job will help speed up SL... especially if the CPU is the bottleneck. For instance, if you are running on only 256 MB of physical RAM then that is almost certainly your bottleneck, and an upgrade to 512 MB will probably speed things up more than a faster graphics card.

Virtual RAM won't help make SL faster, but it might help reducing the switching time required to load up the Photoshop you have running in the background.

SL does a lot of work on the CPU to reduce the load on the graphics card...

Can someone explain that to me? I thought we bought buffed up, expensive graphics card to reduce the load on the CPU. I'm confused now.

SecondLife isn't exactly the sort of program gaming video cards are designed for. Gaming cards expect 3D models to be re-used, expect textures to be small and re-used, and expect lighting to consist of a small number of point light sources. SecondLife's world consists mostly of single-use models and large, single-use textures, and light sources are usually large area sources. If the SL client can use the CPU to convert large textures into smaller ones, and calculate lighting itself, the graphics card can be left to do what it does best: throw triangles and pixels around.

So, essentially, you can get a away with having a P.O.S. card -- 32mb or 64mb, nVidia or ATI -- because it's the computer's CPU that does the labourious work.

I don't mean to be dense, I just want to be sure I am grokking you properly.

You need a good card, but even a good card can't do everything that SecondLife needs to have done. You want a large amount of memory on the card, but even a large amount of memory won't hold everything the card needs. You want a card that can handle large numbers of triangles and pixels a second. What you don't need (I think) is advanced features like pixel shaders.

What I want to know is how well a workstation card (such as the 3DLabs Wildcat series) would do with SecondLife. It seems to me that since those cards are designed for large, single-use models and large textures, they'd do better than gaming cards. But I'm not about to spend $600+ on one just for testing.

Well that does answer my question, now for a suggestion.

The ability to throttle the Framerate. I suggest that a future version of the client have the ability to put a "MAX" on the framerate so that if you are in a position where the FPS could be over 60 FPS or any user set value, it would cut back on the CPU usage (And therefore my wattage use ) and keep the FPS at 60.

SL is one of those programs that actually utilizes the entirety of your computer... My radeon runs everything fine, but SL gets around 15-20 fps on a good day. I'm almost certain it's my cpu.

On friend's out-of-the-box Dells, it's usually the 3d card that's the bottleneck, not the 2.4 ghz processor.

BTW, is there any advantage to increasing the texture cache size to more than 512 MB?

LF