Graphics corruption on Mac G5, Nvidia 6800 Ultra

Hiya, I've been having a problem with my graphics in SL and wondered if anyone out there with the same Mac hardware has any comments that might help isolate the problem. I've logged a bug with Linden Labs a couple of months ago with no results as yet, Nvidia were no help at all. I really want to see if anyone else has similar problems with the same rig before trying to contact Apple about possible faulty hardware.

I only have problems with SL, no other applications are affected.

I am running on a dual processor Power Mac G5 with 2Gb RAM and Nvidia 6800 Ultra 256Mb graphics card ( compared to an older Power Mac G4 with ATI 8500 64Mb card which did not exhibit any problems). The effect has now been seen using Mac OS 10.3.5, 6 and 7 and using all SL versions since 1.5.5.

The effect is that of graphics corruption of the avatar (seeing just featureless skin tone), textures on objects such as buildings, furniture etc showing an incorrect multiple tiling effect and any GUI floating windows plus the GUI buttons at the bottom becoming a badly rendered unreadable mess. The sky will also flicker between a normal gentle graduation in colour side to side, to big blocks of colour.

It most often happens when I have objects attached to my avatar, e.g. custom bodyparts, hair, walk, hug attachments, anything like that, or if am in close proximity to lots of textured building surfaces.

The thing is, this only happens whilst moving the camera - panning, orbiting, zooming etc. It does not happen with normal avatar movement. It usually will not happen immediately after log in but seems to start shortly afterwards.

The effect may either (a) clear as soon as the camera movement is stopped or (b) require a mouse click onto a background object to restore proper rendering of avatar, objects and GUI, or sometimes (c) the effect will stick for a while. (b) is by far the most common, so I am continually correcting the distortion with mouse clicks as I move about within SL. Appearance mode can be almost unusable as the effect tends to stick.

Most of the time, the effects shown in the screenshots flicker crazily between corrupted and normal as I move and stop the camera respectively, its really maddening !

I tried reducing all graphics settings to a very basic level, with no luck.

I've attached some screenshots, taken a while ago, showing the rendering corruption.

pic1 : shows corruption of the GUI and textures
pic2 : also shows corruption of an av in appearance mode
pic3 : shows corruption of GUI and av in normal mode - note minimap
pic4 : regular shot for comparison - compare floor textures etc.

Many thanks for any comments or suggestions anyone might have

Help !

I don't know if this will help, but....

I was having various problems with SL. I wasn't sure if it was the mac beta or my mac. Most of the problems may not have been related to graphics, but the display graying out and telling me that I must restart my computer.

I did the hardware test and everything checked out ok.

I finally broke down and did the archive and reinstalled the Mac OS 10.3.2 on my new dual processor G5.

While I was in the Apple store, I asked about this. They said, bring it in. I asked, but hardware is fine and I did a clean install. They said, bring it in. I asked another Apple Genius, ok, tell me, is there something wrong with the G5 dual processor??? Even after the hardware test said everything is ok?


Long story short, I did bring it in and the logic board was replaced. Don't know if this will help at all.

Hiya, thanks for the reply, sounds like you were having Kernel Panics, which do result in a greyed out screen as you describe, in your case due to a hardware problem.

I have been wondering in this case if I may have a hardware problem with the Nvidia 6800 Ultra graphics card, but the problems seen only effect things contained within the Second Life window, and I would have thought that the graphics card freaking out would also affect the whole display area - so I'm hoping the nice Tech folks at Linden Labs will look into it as a bug, and it is indeed on the published bug list I see, which is heartening, as it is sooooo frustrating to have to deal with all the time

I have the same problem with a geforce 4 ti

Hi Kurt

First person I've heard of with the same problem ! What system are you using out of interest - I'd be really interested to see screenshots if you have them. Do you find the corruption to be flickering in and out constantly as you move and pan around ?

Speak to you soon

i have a G5 with an nvidia card but no problems, maybe try turning down some settings in sl, that might clear the problem up. not sure what to suggest you turn down or off but it might be worth playing with



jester

Hi Jester - yes I already tried turning all the settings down, with no luck, still got the corruption.

Is that the 6800 Ultra card you have on your G5, and on a dual processor machine ? Just looking for similarities and patterns....

Hmmm... after all this time reading about how wonderful nVidia cards are as compared to ATI cards.

I run a G5 Dual with 2GB RAM, and the ATI Radeon 9800 Pro Mac Edition (256 VRAM). I have zero problems with SL, rendering and speed - as long as I am not in one of those overloaded, old sim servers and a club with 45 ppl and all their attachments. NO video card is going to overcome that. Obvioiusly, your screes shots are at home and the sim should not be the problem.

When in good sim, I can boost all the settings and have a wonderful SL experience.

Have you tried adjusting the disk cache size in Pref's? Try lowering the cache size and see exactly what the card wll handle.

Are you running other applications in background? I have had problems when I have several other applications running while in SL. As you know, SL is a major resource hog. It could well be causing kernal problems with mutiple applications running - especially on a dual processor Mac. Remember all the major problems with Kernal Panics and crashes when Apple released the first dual processor Mac's? LL may have some problems with compatibility for those running latest Mac OS version, nVidia cards, and the latest version of SL.

Just my 2 cents worth....

i have a single 1.8 ghz with a a nvidia 5200fx i believe. no problems like you have described.

one other thing i can think of, what is the vram set at in sl? is it more than you card her somehow? or less than you have?



jester

Hi Jester, thanks for the reply, the main reason I asked about which Nvidia card was because I've heard comments around the web about the 6800 Ultra, being as new as it is, having rather early and incomplete driver software for the Mac, I'm trying to catch up with someone with a similar rig. Must also speak to Kurt about his probs with the Geforce 4Ti.

VRAM setting is at 256, as per the card. I tried reducing it to no avail. I also tried reducing the disk cache as mentioned above by Elror. As regards multiple apps, most of the time I only have SL running. Basically I can't find anything that removes it completely, except for having no attachments worn, and I'm even then when I'm in close proximity to a lot of building textures or in direct contact with another attachment wearing avatar I still get it. Weird !

I only get problems with SL, and only contained within the SL window and then only specific parts of the SL interface - which seems to suggest it is a problem with SL and/or 6800 drivers rather than a hardware fault...?

Ahhh my old ATI Radeon 8500 was slooow but at least it didn't do this, lol

hi dee

the main problem is the 6800 ultra i had for months a problem that i couldnt change outfit since the last nvidia i can change outfit again but i do still have freeze ups, on some forums it siad there was something wrong in the bios setting of the first released cards, i did go back to the shop where i bought it and they could not even order a new 6800 ultra for me, but something wrong with these cards that for sure the only good thing about it is the store returned my money back and i still have the card lol but still have freeze ups and crashes

I think we have the same problem. I have recorded it as a movie. But the movie is over 700 MB. I would describe it as buffer over flow. And I've only experienced issues with second life. It works fine in q3a, unreal, unreal 2003, halo, maya, animation master, poser, extra.

It seems to happen depending on the camera angle. I now know not to zoom too close or to zoom to far. Usually if it get scrambled, I can turn back word and forward till I find a spot where the problem doesn't happen.
I've also experienced it in the player editor. But that just might be because of zoom.
Also it has an increased chance of happening high in the sky. 700m+ AT 700M it's not just the gui that goes bad, but the player model.
There seems to be other posable causes, like it might also be triggered by having allot of transparent textures. I hate mentioning other possible causes, because it make the hole problem sound less real and more like I'm crazy.
I found if I took off all my clothes, and put them on one at a time starting with under wear and working my way up. that the problem was less likely to happen at 700m+

it's so anoying not being able to read what people type.

Hi Kurt, that's interesting, and sounds very similar in nature. I only experience it in SL too.

Definitely a function of camera movement and also definitely in the player editor as you say - those are the only two things which trigger it for me. I have to re-pan or zoom and/or click on the sky to clear it (for a few seconds till it corrupts again), although the player editor sometimes corrrupts so badly I can't clear it at all till I come out of that mode.

As I said, it seems to be worse in proximity to a larger number of textures, such as being in a building, i.e. surrounded by them, and you mentioned transparent textures, thats also interesting as I wonder if it could be related to the fact that I see it being triggered by (invisible) hug/walk attachments or hairpieces and stuff.

Interesting that it's on a different card too. Buffer overflow ?, I don't really know the ins and outs of GPU operation - I hope the Lindens are listening though, for when this bug gets to the front of the queue, as it's something I'm desperately hoping is going to be fixed because it is such a problem all of the time.

Yeah, I get stuck not being able to see the typed chat too

I'm sure the fact that there seems to be a delay before it really kicks in after log-in must be relevant also but I just don't know how - some kind of build up of textures in a buffer perhaps ?...

I'm actually tempted to throw out my Nvidia 6800 and downgrade to a lower spec ATI or something in the meantime just to fix it....

Of course as nightmare1212 commented, there could be a hardware issue, but then, I can't see why only SL would be affected...?

Thanks all

hi dee
well look up forums on google just type 6800 ultra and you will see that many have troubles with that card and alot say its a bios problem of the card it self, you can flash the bios your self but thats not easy and can blow up the card if done wrong, there are lots of forums about troubles with this, it seem sl does have more problems with it then other games i played half life 2 at full setting no problem on that part only sl seems to not like this card, i am glad after the new update i can change again after looking the same for over 3 months if i wanted to wear something else my avie was messed up in way like the pics you showed

dee check your bios version if its the same as this one

bios version: 5.40.02.10.14

thats the bad bios i have also in mine

Hiya nightmare 1212

I looked that up but it looks like the PC version of the card. I've got ROM revision 2119 - it's a Macintosh card remember, which is a different physical hardware design to the PC version in the case of the 6800 - dunno how that relates to the BIOS version. I have no idea as to the equivalence of the circuitry on this card Mac vs. PC.

Thanks for the thought anyway - it could be that updates are in the offing of course for the Mac version of the 6800. I certainly remember applying flash updates for my old Radeon 8500.

Thanks

hiya dee

be sure to check tech forums on on mac nivdia systems and check if you have the lates driver for your system, i do have pc but your problems looked like the ones i was having for over 3 months, hope get it fixed soon

She on a mac, Apple manages the geforce and ATI drivers. The latest vertion is included with each update of the os. IE if she on os x 10.3. And when she runs system updater, and no updates show up. Then she running the latest driver. If she tries to find a driver update. She'll mistkenly install an old vertion of the drivers.

btw when you experncing the error, and you move the camera around the distortion changes right?

texture are stored in a buffer. A buffer just a fance word for a peace of digital papper.
this would be a black in white texture of a v
000000000000
001000000100
001100001100
000110011000
000011110000
000001000000

But to demo a buffer over flow it would be better to demo it with this texture. Witch would be horizontal black stripes on a white background.
000000000000
111111111111
000000000000
111111111111
000000000000
111111111111
000000000000

a buffer over flow is when for one reson or another some thing intefers with stored textures. For instance if the texture start in the wrong place. (same texture)
222111111111
111000000000
000111111111
111000000000
000111111111
111000000000
(because the texture started late, the texture end up storing the last 3 0 in another texture)

other times a texture ends up reading from the wrong point. in this case the last 3 0 end up on the top row. This use to be a bug that showed up in side scrollers.
000111111111
111000000000
000111111111
111000000000
000111111111
111000000000

other times one texture over writes another. So when the program trys to draw the texture they end up drawing another texture.

Thanks for the explanation about buffer overflows - interesting stuff, and in answer to your question below...



Yes, moving the camera causes the distortion to flicker through different patterns - mainly differing in texture tiling/repeats/orientation on prim surfaces, as well as the UI buttons etc being a pizellated mess and the mini-map being full of horizontal streaks. Basically completely disorientating !

I've now bought a cheap used FX5200 as a stopgap off eBay and I'm gonna get by with that till this is fixed on the 6800, for the sake of my eyesight and sanity, lol

Thanks again Kurt for the analysis

It could also be incorrectly-bound textures or something (in OpenGL, when you draw a triangle it uses whichever texture is set to be drawn with, and in a complex system like Second Life it's easy to lose track of which texture is being used).

I've noticed that on my 12" Powerbook (FX5200) sometimes these problems happen intermittently during certain game state changes, like when switching to the appearance editor.

I use to think switching to character editor was one way to cause the problem. And it may. But I wouldn't be surprised if part of the problem the the character editor is it move the camera. and if moving the camera can cause the problem. It's not surprise that it also happen in the character editor. Witch move the camera around for almost every setting.

Kurt, it's also my gut feeling that it's the camera movement affecting appearance mode, as that always seems to be the common factor in any corruption that occurs.

Well, I'm now running with a 64Mb FX5200 in place of the 6800 Ultra - I hope not for too long as it's definitely (obviously) slower and laggier, and I may even have to turn off Shiny Objects , but it does avoid the problem - at least I can see clearly now !

And of course, it would seem to prove that the fault is related to the 6800 Ultra specifically (and by the sound of it the 4Ti too), but whether the problem lies with drivers, hardware or the SL client or any combination of those three remains to be seen....!

My G5 sure is so much quieter without the 6800 fan revving up all the while, lol.

I have a long out standing goal to purchase a g5 tower. I'm waiting for the next model to come out. How noisy was it? Have you thought about talking to apple tech support? perhaps they'd send you a new card. If you can convince them that it's a hardware issue. Even though it's probable not.

Hi Kurt

Actually, it's generally quieter than my G4 Sawtooth tower, but when the fans rev up under heavy load it can be mildly distracting - its noticeably quieter without the 6800 so the Nvidia fan is a not insignificant factor here. Most of the time it's whisper quiet but just sighs and whooshes every now and then as the various fans kick in. I wouldn't worry about the noise of the G5 too much. I hear that the dual 2Ghz towers are less prone to fan revving than the 2.5, even without the liquid cooling.

It's been revving less too, without the 6800 so that card must have been nudging the temperature sensors in the PCI cooling zone significantly

I am thinking of trying to RMA the 6800 under Applecare, just to get my hands on another specimen, just in case it is overheating - Temperature Monitor shows temperatures of around 56'C on boot up for the GPU sensor, rising to a max of about 75'C.

I do wonder if the lower clocked 6800 GT would act any differently, or whether it really is a driver problem or SL client incompatibility - I just do not know.......

If you get a G5 tower - DO NOT drop a PCI card screw down into the bowels of the machine - oh my god you just wouldn't believe.........

New and unexpected finding - went browsing the many and varied vendors at Phantasie Island (lots of texture variation I guess if that's relevant) when, hey my SL window started acting up again, with the Nvidia FX5200 now, but to a lesser degree - now the problem is mainly confined to textures, most of the GUI seems OK, though the minimap goes sort of white. Appearance mode just a hint of the previous problems - so basically the FX5200 showing a few similar symptoms but to a lesser and slower degree. Clearing my cache seems to have calmed it down, but I am REALLY confused now, dunno what action to take......

no idea, but your temp seems bit steep, my 6800gt barly go over 50c (fan at 1600rpms ish) , and i run with no psu fan, im still amazed i managed to boot mine tho, 350w with 9hds 4cdrs 1dvd, and various pci's

wish i had a clue about mac's, i never touched one.
(well ok i did once, and it was scaryyy)