Local Lighting - Why such a hit?

So I wanted to play with some of my graphics options today to see what I could do, and have to ask:
Why does local lighting take such a hit to performance. As in going from perfectly fine to unplayable.

Are there plans to improve the performance of this? For the curious I have an x800GT and it shouldn't be having any issues handling something like lighting. Does anyone else use? Find it causes such a massive hit?

LL right now is all software / cpu, wait for them to finish with hardware light thats currently on preview for now.

The good news is that the new lighting system is a true pleasure to behold and I think it's pretty much done and ready for the main grid. All they REALLY need to add is LSL commands to alter light settings. I'm not exactly sure what they were thinking when they made the current lighting system that's still in use.

Thats good to hear, I'm interested in seeing the new lighting. Anyone know what they have in mind for a time frame?

Thought it was end of summer, but we never know really.

Took some pics of random stuff i have, in this thread , as of right now just HW light, is very very short distance, not to sure how many max lights (6?) but it kept popping in and out when i moved barly 2 meters from several lightsources, hw+software light works far longer, had 19 ish fps with it on.

(x2-4800,4gig ram, 6800gt-pcie. 1600x1200 window mode)

For SL i dont mind getting 10 fps really, nothing happening so fast anyway in here, under easy if it has 30+ avatars ~.~

Thili,

Excellent work on those pics, your time and effort has benefited us all. I am really excited for 1.91 to come out now, thank you!

Feel free to play with Second Life Preview 1.9.1 for yourself. If you find bugs, please report 'em from HELP menu ---> REPORT BUG within. All of it helps to get it released faster and replace 1.9.0 on the Main Grid.

The "current" Local Lighting does blow chunks, and it's such a relief something much better--this new lighting system--is coming along to replace it in short order.

While I'm sure many of the users appreciate the hardware lighting.. I have to wonder how this scenario plays out in the board rooms..
"Should we create hardware lighting or create a functioning economy that won't collapse around our ears?"

"When's it going to collapse, like tommorrow?"
"No..probably not tommorrow.. "
"is the hardware lighting cheaper?"
"Should be"
"let there be light!"

Local lighting didn't used to be NEARLY as bad BEFORE SL 1.7. LL seriously screwed up local lighting with SL 1.7 and couldn't/wouldn't fix it. Basically, the problem is lots of small complex prims (like twisted, hollow, revolved tori) and it made a light. Jewelery ("bling" tends to be mindlessly lit and contain MANY small (prim tortured) prims, which causes mega lag. This didn't occur nearly as much before SL 1.7. LL tried some tricks to improve this by adding attachment LOD and something else I don't recall offhand, but nothing helped. I guess they just didn't/don't know HOW local lights got so screwed up.

SL 1.9.1+'s lighting is better but can still grind SL to a halt if one of the "all local lights" light details options is enabled and there are lots of flex prims around (at least 6 and 1 light will start showing the slowdown) and slide/rotate texture animations will become jerky.