Troubleshooting Region Lag

Posted on Jan 3, 2014 in Tech Blog

One of the common questions and complaints is concerning region lag.
There are many issues which can contribute to “Apparent” region lag:
1. Your internet connection speed
2. Your computer hardware – CPU, Ram, and Video Card
3. Number of people in your region
4. Number and type of prims in your region and surrounding regions
5. Textures in Your Region and surrounding regions
6. Attachments on yours and other avatars
7. Scripts

The most obvious, but commonly overlooked issue is your connection speed. The region needs to send and receive data to/from your viewer, if your connection speed is slow, this can give “You” the appearance that the region is “Laggy”.
Sure, you may pay big bucks for a fast connection, but it may not always be fast and should always be the first thing you check. You can also have someone else come to the region and see if they have the same experience, if they do not, it is likely not the region.
Remember, “Your” connection to a region is “NOT” the same as another user… unless you are both using the same internet connection. Each user’s connection follows different paths to communicate to the region servers and “Any” trouble along the way can cause problems.

I don’t have any issues on “XYZ” grid… why do I have them here?
Again, your connection to “XYZ” grid may be shorter, better, etc., unless they use the same provider as us, your connection variables will be different with them.

When it comes to computer hardware, there is no general rule of thumb, but you should expect better performance from newer, better technology. Your graphics card is probably the most important aspect of your hardware as it will see the most load.

Your region will generally perform better with less people in the region. As the number of users increase, so will the demand on “All” variables. Your hardware will need to work harder, our hardware will need to work harder as more data is moved around.

The number of prims in a region will affect performance of a region. Each prim has an impact on the physics engine of the region as will each texture. The size and type of a prim matters as well… a torus will impact the region more than a standard cube. The type and size of textures is important.
The larger a texture is, the more time it will take to download/process and display.

If your draw distance is set high enough to see into a neighboring region you will need to account for the downloading and displaying of all prims and textures in that region as well, including any attachments an avatar there might have.

Scripts really don’t have as much impact on the regions performance as some might think as other things take priority and what is left is used for scripts. This is “Generally” the case.

So how can you troubleshoot a laggy region?
You can start by using some of the viewer’s built in tools.
There will be a “Statistics” option in your viewer… find it, open it and make some observations.
StatisticsBar
The FPS and Bandwidth readings at the top under the basic heading is “Your” FPS and Bandwidth stats, to see the region’s stats you’ll need to look lower under the simulator heading.  Simulator FPS values of less than 43-44 will start to display “Chopped” movement.
The time dilation is a very important value. 1 is a very good and represents the region is seeing time in real time. A general rule would be that a region with a dilation reading better than .89 is not lagged at all, while a region with a reading of .1 is ready to crash.
Look at the Total Frame Time and all sub categories.. you will see a spare time category which represents how much free time a simulator has to perform other work. If this reading is very low it means your region is loaded and doesn’t have any “rest” time.

Best use policies:
1. Use the smallest texture possible. A small texture will require less data transfer and will load your video card less.
2. Position your prims to cause the least amount of collisions.
3. Set your draw distance to the lowest setting that is still acceptable.
4. Try to use as few complicated prims that you can.. a torus will require much more overhead than a standard cube.
5. Change your graphics settings in the viewer. You can find a fair amount of performance gain simply by tweaking some of these settings and in many cases, you won’t “See” a difference.