There is a problem with Deferred Render (L&S = Lighting & Shadows) crashing some viewers. The Firestorm Viewer team thinks most people cannot run L&S. That may say more about who is using Firestorm and Phoenix rather than SL users. But, as far as I know there are no good stats to answer the question of how many people can run L&S, at least not in regard to SL users.
As we move forward this will be a more important issue. It certainly makes a difference in how Second Life™ appears on your screen.
What it is?
Deferred Rendering is a high fidelity render of lighting and in some systems shadows. There is no limit to the number of lights that can be rendered, which is a big step up from the 6 or 8 lights we could previously render in SL.
Lighting is done per pixel for speed and several other advantages. There are some advantages that will only kick in when we get the coming Materials System. There are some anti-alias and transparent objects issues with it.
The implementation in SL is customized for SL. So, if you read about deferred render on various sites, it may not sound exactly like what we see or are familiar with.
According to Unity3D to use deferred render requires a graphics card with Shader Model 3.0 (or later), support for Depth render textures and two-sided stencil buffers. Most graphics cards made after 2004 support deferred lighting, including GeForce FX and later, Radeon X1300 and later, Intel 965 / GMA X3100 and later. However, it is not currently available on mobile platforms nor Flash.
So, it would seem this is another factor that is keeping Second Life off mobile devices.
Changes in Viewer Settings
Recently the default settings for video cards changed. The video card tables were updated. More settings between LOW and ULTRA were added. These changes are directly related to the Lab’s effort to base default feature settings on actual frame rates related to specific video cards. The Lab is trying to classify cards by actual measured performance.
Because of rendering system changes the Lab needed to reclassify video cards. In doing so they decided more granularity was needed in the settings. That is done to give the most people the best experience and performance and base it on actual measured performance.
However, as people upgrade to new viewers they find that they cannot run the viewer at previous settings. The graphics settings need to change. Not knowing this, people’s reaction to the problems is to think viewer is broken and switch back to the last previous version.
I suspect this is why the SL Viewer will on occasion force an update in the viewer’s graphics settings. Third Party Viewers (TPV) are less likely to force settings resets and some use different default settings than the SL Viewer does. I suspect this contributes to why some think one viewer works on their computer and another doesn’t.
If your updated viewer starts crashing on login, change your graphics settings to LOW and then login. Once logged in you can start increasing the quality until you run into problems.