About Lag

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GUIDE: LAG


Key words: lag slow framerate fps

INTRODUCTION

There are a few different types of Lag in Second Life. SL is a very cutting edge application which will manage to push the limits on much of your computer hardware. Your video card, CPU, memory, and your network will all be far from idle while you explore and enjoy Second Life.

Video:

Your graphics card will be constantly busy, things will almost always be moving around, disappearing, reappearing, and you will always be loading textures as you move around.

Due to the dynamic nature of the SL world, some very fast algorithms (ie BSP trees) can't be used here which are used in most 3d games which get to use a "static" precompiled map for their 3d environment. This means you will get a lower Frames-Per-Second rate here than you will get with most of your 3d games.

Please Note: It is quite typical to get only 10-20 Frames Per Second even in quiet areas of the world, with a fairly new graphics card. DRAW DISTANCE can have one of the biggest effects on your frame rate, and is always the first thing I recommend lowering if someone is getting a severely low frame rate.

Your video drivers can have a big impact on your performance as well. Video card manufacturers are always finding faster ways to do the same thing, and they incorporate them into newer drivers. If your drivers are more than a few versions behind, it is highly suggested that you upgrade them.

CPU:

The CPU does a lot of work in SL compared to other applications. Everything that moves in the world has to be updated, and SL is a very dynamic world. SL will almost certianly run your CPU at full 100% utilization the entire time you have the program running. Due to the dynamic nature of SL, a CPU can often have more of an effect on improving your performance than a new video card.

Network:

Your internet connection will also be used heavily, especially as you're flying around the world. Expect your bandwidth to idle at around 20-50 kilobits per second, and peak in the hundreds of kilobits per second while moving around or in a crowded area.

These are the three major sources of lag. CPU, Video, and Network. Often, when one is lagged, the others can appear to have lagged down as well. Here, I will try to give some advice on how to speed up each. Once you have eliminated all sources of lag, then you should go back and re-enable the options you are willing to compromise speed for.


VIDEO OPTIMIZATION TIPS

Video

Here are the settings I recommend for those who are running minimal hardware or who are having trouble with crashes:

Open the Preferences window (Ctrl+P)

Under Preferences / Display tab:

- All checkboxes listed next to "Performance Options" should be UNchecked.

- Avatar Rendering to "Normal"

- Terrain Detail to "None"

- Uncheck Run in a window

- Use a low resolution, such as 800x600 or 1024x768


Under Preferences / Options tab:

- Check ON AGP Graphics Acceleration if you have the option

- Texture Cache Size should be set to small if you have 512MB of memory or less, or large if you have more.

- Set your video card memory size as low as possible (though you may want to turn it back up if everything seems too blurry to you)

- Move Object, Tree, and Avatar Detail sliders all the way to the left

- Check ON Avatar Vertex Program (turn this back off if you keep seeing avatars folded up into themselves)

- Set Draw Distance to 64 (very important, this is the biggest factor in video speed)

- Fog Distance doesn't appear to have much of an effect, set it to your preference.

- Drop Draw Distance - set to 0, if you have draw distance set to 64, this won't matter anyway.

- Bumpiness Draw Distance - set to 0 (it won't matter if Object Bump is off anyway)

- Max Particle Count to 256 (the default is 4096, you can also disable particles temporarily with Alt+Shift+=)

- Outfit Composite Limit to 5 (no idea what this does, I think 5 is the default, and I don't see any differences in performance when changing it)

Additionally, it can help a lot to make sure you have the newest video drivers installed. If your drivers are more than a year old, chances are you will probably get some noticable improvement by upgrading them.


Network

Bandwidth: In the corner of your window, you should see two small vertical indcators. The one on the left is your PACKET LOSS, the one on the right is your CURRENT BANDWIDTH. These indicators can be green, yellow, or red, depending on the percentage.

Bandwidth is not as important of an indicator of lag as much as packet loss. If you see ANY indication of packet loss, that's not good. If you see it every once in a while, or in very busy areas with a lot of people, that is normal. But, if you're getting any significant amount of packet loss in quiet areas or while flying around, you may need to adjust your Bandwidth under your Preferences / Network tab. The exception to this is that some packet loss seems to occur regularly at busy hours.

1. Start with 300 kbps as your default. 2. If you're not experiencing any packet loss, but feel like the world is loading too slowly and your bandwidth indicator is often yellow or red, then raise your bandwidth higher. 3. If you are experiencing packet loss, reduce your bandwidth down until it stops.

Disk Cache Size: - I recommend a reasonable setting around 200MB. You can set it higher, but then I'd recommend purging the cache occasionally to keep it working efficiently. Higher cache sizes tend to slowly degrade performance over time. If you set it too low, then you're always downloading things over and over again. 200 seems like a reasonable compromise in size and performance.

Also, you may want to disable streaming audio (Preferences / Audio tab) if you do not have enough bandwidth or want to save some CPU cycles.


CPU/Memory

- Rebooting your computer before starting SL can help get better performance. - Close as many background programs as you can while running SL, especially P2P programs (Kazaa, Gnutella, Shareaza, etc) - Defragment your hard drive occasionally. - SL works optimally with 1 GB of RAM (that's 1024 MB). More is better, but the payoff is much less beyond 1GB.

Tip: If you need to run background applications while running Second Life, you may want to try lowering the Task Priority for newview.exe just a little bit to give those programs a chance to run a little more smoothly. Don't do this unless you absolutely have to, because it will slow down the SL client. I do this often when I'm browsing the web while running SL, as SL tends to eat up all of my CPU and makes my web browser very slow.

Additional Information:

- To view your video and network status, press Alt+1 - Typical framerates are between 10-20 FPS in non-busy areas - Typical network traffic is between 20-50 kbps in non-busy areas

Lag occurs most when: - Your Draw Distance is too high - There are many physical (physics-enabled) objects nearby - There is a large group of people nearby - You are moving (and therefore loading new geometry, textures, and sounds) - You or other people are playing sounds or animations - When many objects are moving around nearby - You have "fancy" graphics features enabled (Local Lighting, Object Bump, Ripple Water, Shadows, etc)

Example Frame Rates with various configurations: - 20 fps with nVidia Ti4400, Athlon XP 2100+, 1GB memory - 10-15 idle FPS with nVidia MX420, 533 Celeron, 256MB RAM

(please IM Kex Godel with your frame rate, video card, CPU, and memory to contribute to this list)


contributor: -Kex Godel