Tuesday, July 20, 2010

Did You Know No. 1 (Level IV)

Written 20 July, 2010

Did You Know?

No. 1

(Level IV)

Welcome to the first Did You Know?

This feature will tell you something about the Second Life interface or the grid in general that you may or may not know.

Today, server version and the statistics window.


A couple of weeks ago Linden Lab rolled out server 1.40. The grid has been running on 1.38.

1.40 introduced Havok7, a new physics engine. Havok7 replaces Havok4, which replaced an even earlier version of Havok two years ago.

Physics engines enable moving vehicles, animated animals (except the simple circling ones), and things like bullets and rolling rocks. Physics also allows avatars to move.

Physics put a large load on the server, and too many physical objects can kill performance. For this reason it's best to switch physical objects off when they're not in use. So a new physics engine makes for better sim performance and hence a better Second Life experience.

In the five minutes server 1.4 was operational earlier in the month, I noticed a significant performance improvement on both Whimsy and Whimsy Kaboom. Kaboom has a large load due to the many scripts at the robot sanitorium, and has been experiencing a bit of time dilation (not enough to make for a bad experience, but enough to worry me).

Well, with 1.40, which was rolled on about 9 AM Linden time today, Kaboom's time dilation is almost gone. The simulator is running a solid 44 frames per second.

And so now for the Did You Know?

Did you know you can determine the server version of any sim you're on? Simply drop down the Help menu at the top of the screen and choose About Second Life. You'll see not only the server version, but information about your viewer, your computer (operating system, processor, RAM, and, especially useful for Second Life, video card).

If the server version is 1.4, your sim is running Havok7. If it's V. 1.38, you're still on Havok4. Sims are rolling on today and the upgrade should be finished by tomorrow. If the Lindens don't roll back, we should be permanently on Havok7.

Here's a bonus:

Did you know SHIFT-CTRL-1 (CMD on the Mac) will open your statistics window? Here you can determine:

The statistics window provides performance data for the simulator-- your Second Life region. You can spot simulator lag, but viewer-side lag (caused primarily by particles, textures, and your video card's ability to fender millions of complex polygons), is far more often the culprit in the gender "lag" everyone talks about.

Frame Rate: (how many times Second Life updates per second; higher is better, as you can turn, walk, and fly more smoothly).

Internet Connectivity: A low Ping Time means fast response to your key presses and mouse movements; Packet Loss tells you the percentage of data lost in transmission. Bandwidth tells you how fast data are coming in and going out.

Simulator Performance: Time Dilation is how much molasses effect is going on; in other words, how much time is slowed by load on the sever. In other other words, how much lag you'll experience. SIM FPS is another measure of how much load is on the processor. 45 is optimal, 44 acceptable. Physics FPS is a measure of the amount of physics load on the simulator. 45 is optimal.

Avatar Data: Main Agents tell you how many avatars on on the sim. I have no idea what Child Agents measures. Oh, wait! The Wiki tells me it's the number of avies outside the sim who can see into it.

Objects and Scripts: How many objects are on the sim, how many scripts, and other script data I don't begin to comprehend.

Time: Tells in milliseconds how much processor time is used on objects, avatars, scripts, images, and physics. Total Frame Time should be less than 22.3 ms.