Vertex Shaders and NVidia 6800 card?

Is it correct that Vertex Shaders are disabled in the Mac OS X client for a machine running a NVidia 6800 Ultra 256mb AGP graphics card? It's just that the card is supposed to fully support this feature, but SL preview won't let me switch it on

I believe that the release notes say that vertex shaders aren't working yet on -any- mac builds no matter what your card is. I believe it also says they're working on it or it's coming soon.

I've just done a bit of comparing. I jumped to Nexus Prime (Gibson/Bonifacio) both in the Preview 1.9.1.13 and in the main grid, leaving the settings the same in my Mac (they're pretty low — it's a 2-yeat-and-a-half-old PowerBook G4). This mostly means everything off but Shiny, all the acceleration thingies on (AGP, Vertex Shading), Bump Mapping & Cloth, and then on the Graphics bit just having 64 draw distance.

Naturally, for the Preview I have some "additional" settings: lighting on for "nearby sources" (the ATI Mobility Radeon does not allow any further settings beyond that) and flexiprims on. Vertex shaders are, sadly, not implemented on 1.9.1.13.

What I was expecting: although I get HW lighting and flexiprims, the occlusion algorithm in a "dense urban setting" like Nexus Prime should work rather well — except for a few selected buildings, most of them are "solid" (ie. no alphas on the textures). A simple test on the Preview 1.19.1.10 showed me that proper walls could have up to 300% impact on the FPS, so I was curious...

... and then very, very disappointed.

I got precisely half the FPS on Preview. I went to the exact spot and turned the camera precisely the same way. On the Preview I got around 6.5 FPS after all textures loaded (and they take perhaps 2-3 times to load — I guess that's simply because the Preview hardware is not the "latest and greatest". On the main grid, I got 13 fps!

Clearly, one of the two things are not working well:

1. Vertex shaders are far more important than I thought. A simple counter-test on the (maingrid) Help Island confirmed this: turn AGP off and the vertex shaders and your FPS goes down to half!
   
2. Occlusion, despite being great, does not "compensate" for the HW lighting model. I dread to think what would be the FPS reading if the occlusion algorithm would have notbeen implemented!
   

All in all, unless I'm doing something wrong, I seriously hope that the "released" 1.9.1 does have the Vertex Shaders implemented... or else, it seems that LL has to recommend a much higher breed of "minimum" requirements for SL.

So far, I haven't managed to get a friend to test the Preview for me using a PC. This would be a confirmation on the Vertex Shaders making all the difference or not.

On a completely empty sandbox in Preview I still get 25 fps — about 2/3 of what I get on the main grid (+/- 35 or thereabouts). All in all, this is the slowest Preview I've ever tested, which does not bode well — the main grid tends to get 20-30% slower than the "release candidate" preview version (the one where all the debug options are out-compiled from the client). I truly love the cartload of new features on 1.9.1, hopefully I'll be able to see them properly on the maingrid...

I was terribly disappointed when I found out that my card is simply not fast enough for seeing the water rippling effect — it worked so wonderfully well on past Previews without perceptible FPS loss. Alas, reality showed me that a 30% decrease of FPS is way too much for a smooth SL experience. When you've got 25-30 FPS average, a 30% decrease is acceptable. When you just have 12 or so, it makes a big difference!

This is one of the reasons I'd like to be able to try the preview on the actual main-grid areas that I frequent. While Occlussion culling for me has been mostly positive (e.g it has made a nice performance improvement), I've found the Preview grid to perform poorly if I'm exploring, ie wandering around (there are some pretty cool areas to it!).

I've found that the 'cyberpunk city of the future' is REALLY slow, averaging 3 to 6 fps despite culling, and it's a close urban environment.

Meanwhile if I go to the test area (which when I went was littered with stuff, accounting for much the same object numbers, script op-codes and so-on as the cyberpunk city, yet ran considerably faster.

I'm not sure what the difference is but it could be something else entirely that's having an effect. I don't think vertex shaders make a huge amount of difference in terms of performance, in fact I suspect they don't make it better at all, but simply allow you to experience more detailed lighting effects for much the same performance.

One thing I noticed, make my (furry) prim-head a light source (or rather, my nose) had a significant performance impact, must be the fact that such a light is dynamic, it sliced my FPS from 25 in the test area to around 5, maybe vertex shaders would improve that one, maybe not.

That's odd, because making a torch light doesn't impact me at all. Perhaps you've got all lights + shadows on and turned all your head prims into lights? That would definantly go beyond the 6 hardware lights and force software lighting. That has a very dramatic impact on my FPS too.

Vertex shading seems to mean a good boost in my preview client's rendering effectiveness. Without I get 4-9 fps. With I get 7-14

I can only set it to 6 local lights only, vertex shading isn't an option for me on the Mac client (although my card supports it)

The only prim I changed was the nose of my prim-head, which is fairly simple (only about 6 or 7 prims). It seemed to kick the crap out of my performance though by doing that, I'll run more tests, but I was running around the same area with and without the light on my face.

Hmm it definitely looks like there is a big difference with vertex shaders on/off... I still didn't manage to get hold of a PC to test it

My RL colleagues and SL friends are always too busy doing stuff on the main grid for me too encourage them to test the Preview, even if it's only for a few minutes

Seems like to me Vertex Shaders only help ATI cards. Vertex shaders on nVidia cards either do nothing for performance (6 series and higher) or hit the performance like an 18 wheeler doing a buck 20 into a newer volkswagon beetle (series 5 or lower).

Vertex shaders on my admittedly dated nVidia 5600 cut my FPS by a factor of 4, minimum.

Vert shaders are NOT noticeably slower on my GeForce 6600GT...

ATI cards do tend to perform better when complex hardware graphics are involved. Or at least, after the Radeon 9700 Pro series. That might be the reason ATI cards seem to do better with vertex shaders active. < shrugs >

The 6800 I have and iirc anything from 6600 up are supposed to have greatly improved vertex shader support. I just couldn't tell you for sure without the option being switched on for macs

Ah, but the question is: Is it faster with it on like with ATI cards? Many people I talked to with series 6 cards (namely 6600 and up) or better (7x00) didn't notice any gains from it where as ATI users notice a huge jump in performance. Though the rest of us with budget cards (GeforceFX & equivalent) suffer hardcore even with VertexShaders OFF. I'm happy the guys with ATI cards are finally getting caught up to us nVidia guys, but do we really have to sacrafice the budget cards to do so?

Dunno about ATI chips as I haven't had one since 1998 or so. After a bad experience with the ATI Rage II+PC2TV, I bought a GeForce 256. I did have an ATI Radeon 9600XT for a month, and a GeForce FX 5700LE for another month, in between the GeForce 3 Ti 200 and GeForce 6800 OC. But then I upgraded to a PCIe motherboard and couldn't get a GeForce 6800 PCIe for around the $150 I paid for the AGP version (which is stupid) so I had to settle for a GeForce 6600GT which isn't that much worse.

Anyway, my point is, compared to vert shaders off, I don't see any noticeable slowdown (or that much of a speedup, actually), in SL 1.9.1+. Flex prims and all local lights + shadows don't lag anymore since SL 1.9.1.13 at least--perhaps that's vert shader-related but dunno. If so, then that's the only vert shader toggle speed difference for me.

My point exactly, with 6x00GT/GS or better nVidia cards there's no performance hit with or without vertex shaders. Anyone with less suffers to the point where they are forced to buy a new videocard because they are unable to break single digit FPS range to where SL becomes playable. I'm worried we're gonna see another minimum spec increase as a result of this.

Vert shaders aren't REQUIRED for SL now, so the minimum spec can still be whatever it currently is. If anything, SL 1.9.1 REDUCES the minimum spec to allow older hardware to run SL because of occlusion culling and reduced software lights (and down to just 2 hardware lights, which anything from a GeForce 256 on up--like 5+ years old now--can at least do).

Couldn't SL be set-up to switch vertex shaders on or off depending on your configuration?
I think that the main thing with any new option that is going to impact the client's performance, then it should be switched off by default unless you want it.
Things like flexi-prims and the new lights I think are fine as occlussion culling ought to give enough of a boost to make them plausible, and I don't really expect flexi-prims to be over-used outside of the test area, and even then the test-area performs great for me). Likewise lights are typically only going to be used in large amounts in clubs I think, so it'll be obvious why that'd slow down and thus you can switch it off if it becomes a problem

But for vertex shaders it's not obvious why you're slowing down (most people aren't going to know what a vertex shader is, it should maybe be renamed to something like "Hardware shading" or something), so it should be left off so you can switch it on if that's what you want, or you know you can run it.

Um. wrong. I'm running a GeForceFX 5500 with Vertex Shaders OFF with Sun & Moon only. It runs at HALF the speed of 1.9.0 when I'm lucky. So explain to me how it reduces the minimum spec? Please feel free to enlighten me on how I can go from running 17 - 20 FPS on the main grid to 8 on the preview. Also keep in mind the past few previews were roughly 25% faster then the main grid releases so if history repeats itself my performance will drop to like 4 or 5 fps on average.

It seems to be very mixed. Some places are slower, but I'm getting higher FPS in other places in Siva than the same places in Agni... and I have a Radeon 5600 with 256M VRAM. Turning Vertex Shaders on lags me badly, but I don't seem to be missing anything by turning them off.

The fastest I get is half normal speed. Most places are even slower. Morris is the fastest place for me atm, anywhere else just slows to a crawl making it unplayable. I've tried disabling Occlusion & Flex prims, it barely gives me 0.5 fps increase. The only time its faster is when I'm in mouselook mode stairing up at the sky when there's nothing blocking my view. Vertex shaders or not, 1.9.1 is horribly slow especially for GeForceFX cards (verified this with a few other GFX users).

GPU hardware vertex and pixel shaders are not required at the present time for a very simple reason: they are almost entirely unused in the SL client anyway. Only the odd candy effect like water rendering employs them.

We've had countless threads on this topic in the past, including official Linden feedback, and nothing has changed since then. Our modern red hot graphics cards might as well be of 2001 vintage as far as SL is concerned.

So, if you find that SL is running slower than ... well, slower than EVERY OTHER 3D CLIENT OUT THERE, you now know who to beat on.

Working on the next major client version (which *will* use GPU hardware properly and will have amazing framerates, we are told) is probably occupying all of Cory's efforts, but leaving the old client almost abandoned in the meantime isn't particularly praiseworthy. We are paying good money after all, and a lagfest while our hardware goes unused for years does seem rather, well ... uncaring.

Why? You don't have to have vertex shaders on.

I suppose, alternately, SL could keep on looking like 1998-quality 3d.

Turning on occlusion varies from 1FPS slower to like 5-8 times faster depending on the area.

Can't detect any changes due to flexiprims.

Morris is one of the worst areas for me, at about half the speed of anywhere else... probably due to the zillions of test prims using all the fancy new features scattered over the mesa top.

I wonder what I'm doing right, because AFAICT I should be getting the same kinds of problems as you.

I still play a game from 1997, Myth: The Fallen Lords (sequel Myth 2: Soulblighter), my computer can run it at well over 1200 fps, yet I'm perfectly content with it's "meagre", outdated graphics. A game isn't about graphics!
If vertex shaders hurt performance on older machines then it shouldn't be added unless it is off by default for older machines, and switching it off doesn't affect FPS (which some people are suggesting they do, and HAVE to switch on vertex shaders to have fps comparable to 1.9.0).

I don't mind graphical niceties, but SL shouldn't be, and never should be about graphical superiority, it should concentrate on performance and immersion. Lighting is good for immersion and is replacing an 'old' feature which had poor performance, flexi-prims I'm not too bothered about, they could be good for immersion but I'm still a bit skeptical. Occlussion culling is great for performance, and will hopefully be used to further improve the game in other areas (downloading and caching are my big hopes as you only need to load objects you can see) and potentially even LOWER the requirements!

Performance gains shouldn't be immediately offset by adding in new performance-hitting features. Bells and whistles are nice, but only if there aren't so many I struggle to do things because of them

IMO SL is as graphically powerful as it needs to be except for maybe shadow-layers (a feature suggestion in the forum somewhere). You can create most things you can imagine, texture them happily, script them to be interactive in a wide variety of ways. You can simulate shadows with darkened textures etc. It's not the latest and greatest method of doing things, but they work, work well, and without massive performance overheads of things like volumetric lighting or whatever (I don't even know most of the modern buzzwords, I stopped caring in '98 ). Unless new things mean better performance, or new stuff without performance loss, then I'm not happy with them personally
The features I'm most interested in are things like parcel privacy, or more scripting commands/performance, better group support and so-on. Things that improve the experience, not the looks

/uneccessarily long post

You're missing being able to mix alpha with shiny, but something tells me you really wouldn't care. XD