Inworldz is a stable platform... moreso than any other grid I know. But some folks mention crashing and performance issues. So here are hints and tips for how to avoid such problems.
Mind you, nothing totally prevents lag and crashing. Crashes happen. But these hints should help reduce crashing significantly.
CCLEANER. (yes, that's 2 "C's"). If you use Windows, this is one of the best "cleaner" systems I've seen and has done more to help me maintain a stable computer system than anything else. It's free. Download and install the program and use the first two options. Sometimes that's all that's required to get your system to run smoothly.
ADJUST CACHE. Edit/Preferences/Network. Your disc cache size is likely set to 512mb. Unfortunately in Viewers there seems to be nothing which tells your system, "Oh, you've reached maximum cache... stop bombing the system". Cache works poorly. Cache should be somewhere between 512mb and 1024 for the average user, but it's difficult to tell what is best. We recommend 512 and if you can increase to more, try it and see.
CLEARING CACHE. Edit/Preferences/Network. If after time you find yourself crashing regularly, simply clearing cache can often fix that problem.
OBJECT OCCLUSION. Technically this is supposed to speed up your system by not rendering items that are blocked to your vision. Unfortunately it doesn't work at this time... and can cause severe lag. So: advanced>rendering>object-object occlusion [uncheck this].
VIRTUAL MEMORY. This is one few people know about, but is very important. In Windows, Virtual Memory is your computer using hard disc drives to store constantly used information-- kind of an artificial RAM (I don't know how it works on Mac. You'll need to research). Chances are your VM isn't set nearly high enough. Low Virtual Memory is one of the major causes of crashing.
When I checked my system, my VM was 2 gigs. I increased it to 9 gigs by using two hard drive partitions. Any setting of 4gigs or more is probably sufficient. There is a limit as to how much VM any hard drive is allowed, so if you have more than one hard drive you can set additional VM... although this may slow down things a bit as your system pulls info from additional drives.
In Windows XP, follow these steps to set Virtual Memory (it may be different in Vista or W7, dunno):
Start / (right click) My Computer / Properties / Advanced / Performance Settings /
Advanced / Virtual Memory / Change
(Yes, that's a lot to go through, but that's how it's done.)
It's fairly safe to set most hard drives to at least 4096megs (4 gigs). Save these settings, exit and reset your computer. When you come back in, go back to that area and double-check the new settings have been established. Once you increase your VM, time between crashes should increase significantly.
Unfortunately, there is no way to prevent memory-based crashing altogether, because current Viewers are based on the original SL Viewer, and all have a significant memory leak issue that eventually fill up your VM and cause your system to crash. Nevertheless, doubling or quadrupling your Virtual Memory should significantly decrease crashing. In all but the most texture-packed sims, it may reduce crashing to the point you'll hardly ever experience such.
ADJUST BANDWIDTH. On the same page, check your bandwidth setting. Different systems will require different bandwidth. After experimenting I settled on 1500 kbps for mine. Your internet may require less, or allow more. The best way to test this is to look at the bandwidth indicator bar in the upper right corner of your screen, and see which setting keeps that bar on green the most. If you're constantly going into the red, your bandwidth needs adjusting. Experimentation will determine which is the best setting for your system.
ADJUST GRAPHICS. Edit/Preferences/Graphics. Graphics are even more important than your computer when it comes to VR performance.
Graphics cards. A single-core 2ghz computer with a killer graphics card will likely perform better than a quad-core 3ghz computer with a poor graphics card. A good graphics card is more important than a killer computer system and will have more to do with your overall performance.
Low-Medium-High-Ultra. These settings in your Preferences / Graphics area will directly determine how much stress Inworldz places on your graphics system. If you have a low-power computer you may wish to use the blocky-but-adequate LOW setting. Medium gives a bit better graphics while requiring relatively low system resources. High will require a faster computer and good graphics card, and Ultra will require a "gamer" level system.
Graphics Settings. The graphics settings on your computer will greatly affect your performance. Very few people can use the Ultra setting to advantage. Most people find that Medium or High is best. For low-graphic laptops (especially anything using Intel-based graphics), the Low setting will be needed.
Draw Distance. Most people can have a draw distance of 128 to 256 meters. Low power systems will do better at 64. When in avatar-crowded areas, drop your draw distance to 64 even if you have a good computer; avatars take a lot of system resources.
Avatar Impostors. Avatar Impostors imitates avatars at a distance, but it also destroys those avatar details. Unless your system is low-performance, you're probably okay to click this off. Currently there is a reported bug in the Avatar Impostors system, so having it turned off is probably best. However if you have it off and find yourself crashing regularly, try turning it on and see if it helps. If not, leave it off.
Detail Sliders. On the right of your graphics window are detail sliders. If you're having crashing problems or serious lag, it is amazing how reducing those sliders to Med or Low will increase performance. Unfortunately it will also reduce the detail of your graphics (on Low settings, cylinders turn into hexagons)... but your performance will improve significantly.
Shadows and Advanced Shaders. Shadows are pretty. Shadows are graphics hogs. Unless you have the most powerful of systems, leave shadows and Advanced Shaders off.
Emergency only: Basic Shaders. Some users report serious problems using any shaders at all. If nothing else you've tried seems to be working, turn off Basic Shaders. This will majorly affect the quality of presentation, but if you're on an old, slow computer with minimal graphics, it may make the difference between being able to use the system consistently or not.
CLOUDS. Most folks aren't aware of it, but the routines that created animated clouds in the sky take more graphics resources than one would expect. If you're having regular trouble with lag or crashing, try turning off clouds. You'll wind up with just a clear blue sky... but it may make the difference you need.
AUDIO AND VIDEO. If you're standing in one spot (like a a dance, regardless of animations), audio will likely not cause problems. With very low performance systems, audio can increase lag. But most people don't care at a dance; they're not physically moving much anyway.
Video. My recommendation: don't use video. Unless you're on a Mac, don't even install QuickTime. In my experience it messes with Windows. If you want to view a video, ask the land owner for the direct-access link (if possible).
Video loading can create stop-dead lag, serious performance issues, and crashes systems like a fiend. I have never once, in 12+ years (and growing) of using VR, ever made it through an entire in-world movie without either me or the video crashing. VR video was never implemented correctly and simply isn't worth the major performance drop. You can run a direct-to-computer video (such as YouTube) and Inworldz at the same time with far less drag on your system resources.
In most cases, turn off "auto loading" of both video and music. Switch them to manual so they're not being triggered every time you cross a parcel line.
ADDITIONAL TWEAKS. The following changes may assist greatly in handling texture tracking and other lag issues:
Turn off the option Enable Streamed VBOs
Advanced / Debug Settings / XferThrottle
Change from 15000 to 1500.
Advanced / Debug Settings
FSDestroyGLTexturesImmediately = TRUE
Don't be afraid to tweak graphics settings. You can always reset them to default if necessary. But if you are crashing regularly, the system being stable or unstable may depend on one setting you haven't yet tried adjusting. So take the plunge: try setting your overall settings to medium instead of high, try setting terrain detail and sky to low, try turning off clouds entirely. If it helps, it helps. Don't be afraid to try something you haven't tried yet. It may be just the trick.
So these are areas in which you may significantly reduce poor performance and crashing issues. As I hear of more, I'll add them to this blog. : )