lag hoodoo quick reference

Approaches to reduce lag, within groups sorted in order of effectiveness, more or less. This does not cover every item mentioned in the series of articles, just the ones that are likely to have the most impact. It also omits hardware and network upgrade options. You may review the previous articles for more details.

Viewer and Operating System items typically affect your local experience, and not others. Those dealing with the avatar and the region (AKA sim) typically affect both you and others.

Enable the Statistics bar to monitor the effects of changes with Control-Shift-1

• Viewer Control Panel Graphics Tab (with Custom box selected)
  
  Note that these are trade offs between speed and quality
  
  
  
  
  • Window Size set to smaller size
  
  
  • Quality and Performance slider moved to left one or more steps
  
  
  • Draw Distance reduced
  
  
  • Atmospheric Shaders and Water Reflections disabled
  
  
  
  



• Viewer Control Panel Network Tab
  
  
  
  • Maximum Bandwidth to 500 kpbs, but adjust with experimentation for best FPS
  
  
  • Disk Cache Size to maximum (usually 1000 MB)
  
  
  
  



• Other Viewer settings and issues
  
  Activate the Advanced menu with Control-Alt-D
  
  
  
  
  • Advanced->Rendering->Run Multiple Threads
    
    This is not helpful if you have one single core CPU
    
  
  
  • Advanced->Rendering->HTTP Get Textures (if available)
  
  
  • Disable Voice, and/or Video (Media) if you are not using them
  
  
  • Experiment with alternative viewers
  
  
  
  



• Local Operating System
  
  
  
  • Run spyware scan, virus scan, and defragmentation (on Windows)
  
  
  • Reboot
  
  
  • Disable unnecessary 'helper' applications and crapware
  
  
  • Reduce window system eye-candy, e.g., Windows Aero interface
  
  
  • Give viewer increased priority
  
  
  • Update drivers for graphics card, network interface, and motherboard
  
  
  
  



• Avatar
  
  
  
  • Check your ARC (Advanced->Rendering->Info Displays->Avatar Rendering Cost
    But never yell at somebody else about their ARC; that is rude
  
  
  • Choose unscripted attachments and clothes in preference to scripted ones
  
  
  • Choose clothes and other attachments that use a minimal amount of textures cleverly
  
  
  
  



• Region (assuming you have permission to create/modify within the region)
  
  
  
  • Remove unnecessary prims, and don't litter!
  
  
  • Use large prims to break up view of lots of smaller sims
  
  
  • Reuse textures
  
  
  • Be careful of scripts, as they can potentially cause serious lag
  
  
  
  

That completes this series of articles. I hope you've found it helpful. May your lag be low and your enjoyment high.

lag hoodoo 9: hardware

Before we get started on the main issue of hardware, a couple of things I've read and discussed with others are worth mentioning.

Zauber Paracelsus, whom I don't know from Adam, published a blog article titled 'Reducing Your Lag!!!' that is worth your reading. While much of what he covers I have already mentioned, he did make one statement about the Maximum Bandwidth setting (Preferences->Network) which made me go back and test a bit: 'Put it below 500 and you'll see a huge performance boost.' I played around with it, and found that, on my system, 500 seemed to give me the best results. It wasn't a huge change, only three or four FPS, but that can make a big difference in feel on an otherwise laggy system. Probably the best setting for your system will depend on your particular network, so experiment with it a bit.

Second, especially if you have a Windows system from a major vendor such as Dell or HP, you may have a lot of 'crapware' being loaded on start up on your system. It's worth taking a look on the Task Manager to see what all may be running on your system that you are not aware of. Take a look at this ZDNet blog entry for more details on how to deal with this.

As you work on reducing lag in your virtual world experience, it's important to remember that you can only do so much if your hardware is not up to the task. Just as a tune up, as important as it is, will not make a Hyunadi perform like a Ferrari, so insufficiently powerful computer hardware cannot perform beyond its limits. Obviously, if money is no object, you can buy a $5000 gaming system and very likely dramatically reduce your lag issues, at least those on the client side. I will not go into huge detail as to how to purchase or build such a system, but you can take a look at the Tom's Hardware Build Your Own website for lots of information on that.

However, many of us do not have that sort of cash ready to spend on such a system. There are strategic upgrades that can be made to maximise whatever money is available for hardware improvement. I do not intend to write an in-depth article on hardware upgrading, but I will touch on the areas most likely to affect the performance of a virtual world viewer. I recommend that you take a look at the vast amount of information available on the Tom's Hardware website.

The key to hardware optimisation is in discovering the bottleneck, and there is generally a bottleneck. With 3d VW viewers, the most likely culprits are GPU (graphics processing unit, the heart of your graphics card), CPU, and RAM (memory). There could also be hard disk, bus, or network speed issues. CPU and RAM are fairly easily checked using a monitoring application, such as the Windows Task Manager, the Mac OS X Activity Manager, or the Linux "top" command. These tools can quickly show you, among other things, if your CPU is being utilised at 100% on an ongoing basis, or if your RAM is being overtaxed. On Windows, for instance, select the Performance tab. If one or more of the CPU Usage History is remaining at 100%, or the Physical Memory Usage History is remaining near 100%, the system has a bottleneck in the affected area.

Memory is usually a fairly easy and not terribly expensive upgrade, and if your system has less than 1 GB, you should almost certainly upgrade it. CPU is usually a more complex upgrade, and may require a motherboard replacement, at which point it may make more sense to consider a replacement system. Network speed is usually a function of what your ISP is providing you, though there can be local network issues that cause loss of information and slow down overall performance.

For GPU performance, take a look at the graphics card installed in your system, and compare it to the Second Life recommendations, which will generally be applicable to viewers for Opensim-based grids as well. If you upgrade your GPU, ensure that your power supply is adequately rated for the demands of your system. Typically the specifications for a graphics card will specify a minimum recommended power supply wattage.

Next week, I will wrap up this serious with a review in the form of a quick checklist of things you can do to reduce lag. Until then, happy avataring!

lag hoodoo VIII: what would Henry do?

In this article, I'll look at a few odds and ends of lag reduction that that we haven't covered yet.

The advanced menu, activated with Control-Alt-D (it was originally called the Debug menu, hence the use of 'D'), gives us one or two possibilities to look at, depending on the particular viewer. First, there's an option under Advanced->Rendering called 'Run Multiple Threads'. If you have a multiple core CPU (quite likely if you've purchased you system in the last year or so), or multiple CPUs (less likely), selecting this can make a significant difference, at the potential cost of occasional crashes. If you have a single CPU, this will likely make no difference, and is best left off. If you're not sure what sort of CPU you have, try turning it on while watching the FPS in the Statistics Bar. If you see a significant improvement, then leave it on; if not, turn it back off.

Additionally, on the Snowglobe viewer and a few others that have borrowed its new texture pipeline, there will be a choice in the same menu for 'HTTP pipeline'. If it is there, turn it on. The difference it makes can range from very slight to huge, depending on several factors.

Disable voice from the 'Voice Chat' tab of the Preferences window if you never use voice, as that is an additional running process and a couple of libraries.

Aside from those, a few other things that can be done are general system maintenance issues. I won't go into great detail, as there are plenty of online resources. Defragment your hard drive if you're running Windows. Scan for viruses and spyware. Make sure you are not running services and other applications that you never or seldom use. Update the drivers for your graphics card, network, and motherboard.

Experiment with different viewers. There is no one viewer that is fastest on all systems in all situations, so find the one that works best for your. Some I have found to be generally faster are Emerald, Imprudence, and Cool. But sometimes, they're slower for some people. Also, some viewers have an optimised version available for newer CPUs. Unless your system is quite old, try that.

When in doubt, reboot. That's especially true with Windows, but also applies to Mac OS and Linux, if the system has been up for several days.

Remember, there is only so much you can do with software if your hardware is inherently limited; next week, we'll look at hardware, and then I intend to wrap up with checklist of sorts.