General Discussions

[Maxine Kohime]

Im not very technical, so, please, tell me, what causes lag? Scripts? Avatars? Textures? Let me know, please. Maybe you could it explain it a bit. *smiles*

An advise how to fight lag would be also very appreciated. Thank you!

[Lindal Kidd Helper]

All of those things cause lag.

There are two basic types of lag:  Server side lag and viewer lag.  They both look the same to you, but they have different causes.

Server side lag is caused by things that tax the resources of the server (computer) running the region simulator.  Things like too many scripts, too many avatars (40 is generally the maximum you can get into a regular region).  Too many physical objects, physical objects that are too large (physical megaprims).  Sometimes other servers, like the asset servers that manage inventory items, can have problems too.

One type of lag in particular is the "freeze" or "rubber-banding" that can happen when an avatar arrives in the region and any Mono scripts they're wearing start up.  This one is a bug that (we're told) will be fixed soon.

Viewer side lag happens either because your internet connection gets maxed out, or your graphics card is overworked.  This can happen because of too many high-resolution textures, too many sculpties, too many flexiprims, too high a draw distance, graphics preferences set to a level that overtaxes your graphics card, etc.

SL places a heavy load on its own servers, on the internet pipelines connecting everyone, and on residents' computers.  It's very data-intense, and the more realistic it becomes (whether that's your avatar's appearance or features, or the look of the world around you) the greater the load.

We (well, not me, but the techies) can get into lots of detail...but the bottom line for most people is get a good, fast computer, a top-notch graphics card, and a fast internet connection if you want to play around with virtual realities.

[Suella Ember]

This should be compulsory reading for all SL residents:

http://analutetia.com/2009/06/22/anatomy-of-lag/

[Maxine Kohime]

thank you for your answers, so, here I read:

"So, turning off your AO, entering “sleep mode” on MystiTool, or  detaching everything with a script in it will make no difference at all.  Granted, if everybody is wearing a thousand scripted attachments, they  will notice that their attachments work very, very slowly, or possibly  not at all. But they’re not lagging the sim."

means scripts dont cause lag? So why all say the opposite?

[Void Singer Contributor]

... and physics, and bad connections, and asset server errors and breathing, and ok maybe not breathing....

pretty much anything that happens between your fingers and the data on the SL servers, or an anybody eles fingers and any related data can be a source of lag.

the biggest culprits on LL's end are physics and things that affect physical properties (changing of textures, positions shape, etc). the biggest culprits on your end (other than the obvious equipment limitations and normal crap that affects all your computer use) are overuse of textures inworld, having your inworld settings too high for your computer configuration, and too many other applications open (including ones that load in the background/system tray for convenience).

LL is looking at improving the physics engine, and also removing a second nearly as problematic lag source of disk paging in sims.

the new viewer does help with lower end video cards, but at the cost of increased processor usage... exiting other programs should help with this.

[Void Singer Contributor]

Maxine Kohime wrote:
thank you for your answers, so, here I read:
"So, turning off your AO, entering “sleep mode” on MystiTool, or  detaching everything with a script in it will make no difference at all.  Granted, if everybody is wearing a thousand scripted attachments, they  will notice that their attachments work very, very slowly, or possibly  not at all. But they’re not lagging the sim."
means scripts dont cause lag? So why all say the opposite?

scripts CAN cause lag currently, if there are too many off them, because they can take up too much memory (and any physical changes or physics activity that they create can also cause lag) which causes disk paging (using disk space for memory). this does not happen on all sims, but can happen on ones that contain too many scripts (sometimes from several avatars with LOTS of scripts in their attachments).

the scripts by themselves are not the problem there, but the number of them is.

there is also a specific problem cause scripts to lag (and only scripts). when a script first becomes active in a sim, or is removed from the sim... there is a partial fix for this in the current server rollout which will hopefully be done in a few days time.

[Maxine Kohime]

about ARCs

"But… high ARC does not create sim lag! Seriously! A prim is  just a prim, 200 prims on the ground or attached to an avatar’s head  take exactly the same time to rezz (actually, prim hair will rezz first,  since all attachments have priority when downloading). So what’s the  problem with high-ARC prim hair (or shoes)?"

read more here: http://analutetia.com/2009/06/22/anatomy-of-lag/

So, one says script dont make lag, they just work slower, the others say scripts cause lag, whats up now with...

[Joshooah Lovenkraft Member]

As some people have already mentioned, lag can be caused by a multitude of things, some of which are within your control and others that are not.  In order to get a better understanding of its causes, it is a good idea to at least get a general handle of some of the techy side of things so that you are best able to manage it in your particular circumstance.  Here are a couple of good articles on the topic that explain things in detail, although some parts of it might be a bit out of date.

Not everyone is able to have the latest top of the line gaming computer, so be sure that you are managing your expectations for your particular set up.  While I can have my settings on ultra with beautiful windlight skies & water and even render shadows on my desktop pc, I certainly can't expect the same on my craptastic laptop.  You can sometimes manage a reasonable experience even on a low end computer but you will have to tweak things in order to do so.

Familiarizing yourself with interpreting the statistics bar I also found helpful in determining whether there is something wonky on my end or whether SL is just having a bad day.  I'll also look at the official status blog to see if anything is being reported when I'm experiencing things like transactions, logins or teleports are failing. This real time concurrency graph can also sometimes be telling when you can't log in and the status blog isn't reporting anything as you will see unusual sharp dips in the graph.

[Qie Niangao Advisor]

Void.Singer wrote in part:
there is also a specific problem cause scripts to lag (and only scripts). when a script first becomes active in a sim, or is removed from the sim... there is a partial fix for this in the current server rollout which will hopefully be done in a few days time.

Oh, would that it were true.

Assuming this refers to the same bug, Kelly comments in the jira that the fixes were pulled out for 1.38.1, after major problems with them in 1.38.0.  Also, this bug in fact interferes with more than script execution: it actually throws the sim into time dilation.

[Borealis Karski]

High ARC causes client side lag. A large number of scripts causes server side lag. This means yes, scripts do cause sim lag.