Point me to the answers:

What causes poor server performance in SL (often referred to as lag)? I'm hearing a lot of rumors about it, but I'd like to compile a list.

So far, I hear that:

• textures larger than 512 x 512 will cause performance problems
• hollowed, rounded, cut, splayed, etc. tori (toruses?) will cause performance problems
• thousands of prim attachments to an avatar (i.e. infamous 'hoochie hair') will cause problems

Someone told me that objects set to 'light' will cause performance problems (and I have dozens of objects set to light in my sim) but I want confirmation on this.

Note that I don't want to hear what can be done on the client to reduce lag -- i just want to know what causes problems on the server level.

In my sim, Io, I'm noticing a 'stutter'. If I wander around there will be a hard pause -- I can still rotate but I can't move in any direction -- for like 2-3 seconds. I thought it was just me until I realized that it doesn't happen in other sims and I really noticed it when I put up a rotating spotlight. The spotlight would just freeze for a few seconds before going on its merry way. If all of this has been discussed before, please point me to the thread.

Thanks!

-ee

There are three types of lag:

1) Low framerate, also known as client-side lag. This is things like "light" prims, or large textures.

2) Network latency. This is caused by a slow point in the network between you and Linden Labs.

3) Low server framerate ("server-side lag". This is mainly caused by physics nightmares, especially things like tortured toruses and other double-concave surfaces. Having more than about 3000 scripts running in a single sim will also cause trouble, as will dozens of avatars. Outsized textures can also contribute, as sending them to the clients takes time, but this is very uncommon.

what carnildo said. #1 also includes excessive particle generation.

it seems to me that most of the network and server lag are evident in packet loss that you can see in the small, left bar next to your account balance in the top right hand corner of the window.

client side lag is evidenced by a low local frame rate that you can see in the top portion of the statistics window (alt-1). client lag is very very very common because people don't realize they're causing it. our clients cache huge textures while we're building; and we tend to match particle effects to our own rendering capabilities without thinking about a lower standard.

so we don't realize it's a problem for people until they complain. i've become a lot more concience of my effects lately. it's sort of like designing web pages with the knowledge that most people are still using windows 98 on a machine with 256mb of ram and a dialup connection.