Mystery: Fog slows down my GF4 Ti4200 (even on OLD games!)

OK comrades this problem is the first of its kind - this I can say after countless hours of googling, foraging the web 4 similar issues, etc...


The prob is as simple as they can get:

When playing a 3D game, the framerate drops abruptly to staggeringly low levels (ie. below 3 fps) whenever there is onscreen fog!

And this applies to ANY game, even "old" ones with "recommended" or "optimum" system requirements way below my specs.

My (main) specs are:

AMD Athlon XP 2400+ @ 200*10=2Ghz
nForce2 chipset FSB400 capable
1Gb RAM - 2*512 Dual DDR @ 200Mhz (or 400Mhz, whatever)
Winfast Geforce4 Ti 4200 128Mb VRAM
Maxtor 80GB IDE HDD 7200rpm UDMA133
480W Antec "Trueblue" PSU (best U can get)


L2 cache is enabled in BIOS (in fact, optimal BIOS settings)

No overclocking whatsoever, well-cooled tower & CPU

Microsh*t Windows 2000 SP4, latest updates.

Latest nForce2 drivers.
Latest sound drivers.
Various video drivers (4 testing purposes, detailed later)

As 4 the games, I could cite:

- Incoming Forces: optimal settings= P4 1ghz, 512Mb RAM, Geforce3 Ti 64Mb VRAM. Slowdown occurs during explosions - these are quite detailed in this game...

- Soul Reaver 2: recommended settings= P3 500Mhz, 256Mb RAM, 32Mb VRAM. Slowdown occurs, for example, when facing a waterfall - the vapor (ie. fog) slows down my card to a crawl.

But as I said, the fog slowdown occurs with practically ANY 3D game I play, whenever there is onscreen fog.

Now these are relatively "old" games, and according to my specs, given the type of game I cited ("not-so-demanding"), the aforementionned games should be flowing as smoothly as a fish in the water, fog or not!

Yes, I only have AGP 4X, not 8X, but I've heard that the performance increase with AGP8X is not noticeable on the human scale, besides as I said the fog slowdown also occurs with OLD games, when even AGP4X was barely on the market...

My previous Vcard was a GF4 Mx, I noticed the same fog problems, but then I would think "hey, this GFMx is a weak card, I'll give the GF4Ti a try" so last year I upgraded to my present GF4Ti, but to no avail.


And I know this is purely 3D-video related, and not anything else such as sound. For example in 'Incoming Forces', the framerate drops only if the explosion is onscreen, ie. the tank faces the explosion. Which means that it is the VIDEOCARD which is slowing down!

Of course, windows 32 acceleration is fully enabled...
Besides as I said, slowdown only occurs with fog, otherwise the most demanding games such as UT2003 run smoothly even with resolution & all details set to maximum.


And believe me I have tried all sorts of things:

- unplugging unnecessary devices, such as most usb stuff (no gamepad, modem, ...). I even removed my usb mouse & used a PS/2 one instead!

- turning off all virtual CD drives, unnecessary background apps, (including firewall, antivirus, etc...), only leaving the standard Win2000 tasks.

- installing different Detonator drivers (all WHQL certified), from the oldest to the most recent: 40.72, 44.03, 44.67, 53.03 (latest). Of cos', between each driver, I performed a clean removal: uninstall + nvcleaner.exe to mop up remaining files + reboot...

- lowering Windows quality & performance parameters: no anisotropic filtering, 800x600 resolution, disabling Vsync, etc...
The only setting which, once disabled, resulted in a SLIGHT improvement was the FSAA (antialiasing). When AA was disabled, fog speed up slightly, but the "fog framerate" would still be ultra-low (below 5 fps)

- installing latest sound drivers. I know this is strictly a 3D video issue, but still, just to make sure

- lowering game details. But even at the lowest settings, fog still causes the card to drastically slow down. On the other hand, even with high detail, games run smoothly as long as there is no fog on the scene!

- flashing to latest BIOS. Little chance this would have any effect (and it didn't) but just in case...

- enabling/disabling fog table emulation

None of this worked.


->And as I said, EVEN OLD GAMES can have fog slow down my Vcard to a crawl!!!

And these slowdowns only happen with fog, nothing else. All other 3D special effects (FSAA, trilinear or anisotropic filtering, vertex shaders, pixel shaders, etc...) have no slowdown effect on my card, as long as there is no fog. My GF4Ti runs flawlessly with the most demanding games, even on high detail, as long as there is no FOG in the game scene.
So fog seems 2 be my vcard's weak point.

So the mystery remains whole. And possibly beyond science?


GRRR! This is most frustrating to say the least :upset:

This is an SOS I'm sending forth. I'm desperate now (...)
Anyone who could give me any help of substance or shed some light on this apparently inexplicable phenomenon will have my eternal gratitude, though I fell this issue will call on the knowledge & wisdom of a Master Jedi Computer Engineer...

that sucks, i had an old geforce 2 that used to slowdown when fog and smoke appeared on the screen, (smoke grenads in cs were the worst) but then i upgraded to a geforce 4 ti4200 with 64mb ram(the 64mb version is actually better then the 128 because the ram is faster then that on the 128 version). since then i dont have hardly any video lag. although, i dont really play anything other then halflife mods.

at the risk of being redundant:
get sisoftsandra and run at least the central units, you might want to try running some of the others as well.

make sure hardware acceleration is set to full in windows, and agp is enabled at 4x in bios and windows.

make sure you have enough virtual memory, although i doubt thats your problem.

Originally posted by redwench
at the risk of being redundant:
get sisoftsandra and run at least the central units, you might want to try running some of the others as well.

make sure hardware acceleration is set to full in windows, and agp is enabled at 4x in bios and windows.

make sure you have enough virtual memory, although i doubt thats your problem.

Well yes U are being somewhat redundant, but I won't hold it against you


Running (more) benchmarks will be pointless - each 3Dmarks tests run smoothly and the overall 3Dmarks score are good. but of course, there are no "fog tests" with these benchmarking apps.

And as I said, only fog slows down my Vcard - and even in "old" games!!?! This is driving me mad


And as I also said, yes AGP 4X is enabled in BIOS as well as windows (various monitoring software utils have confirmed this).

And I have 1.5Gb virtual memory, but this is irrelevant since virtual memory is disk space emulating memory, and is therefore ultra-slow so I don't see how more virtual mem could improve things.

Besides if my BIOS/windows settings were really inadequately adjusted, I would notice a 3D slowdown on any recent 3D game, FOG OR NOT.
But in my case, only fog seems 2 B my Vcard's weakness, hence the apparently inexplicable nature of this issue!

which is why only an expert in 3D might B able to shed some light on this...

i didnt read that big long post.

there are 2 types of fog. volumetric fog, which takes a butload of computational power, and limiting fog, which conservers computational power and reduces draw distance.

i didnt read that big long post.

there are 2 types of fog. volumetric fog, which takes a butload of computational power, and limiting fog, which conservers computational power and reduces draw distance.

Of course, it's the first one I was talking about...


All the Vcards I've had, from my good ole' GF2MX, and my GF4MX, to my GF4Ti 4200 128Mb, seemed extremely sensitive to fog - yes, even my latest GF4Ti card! BTW, all 3 cards were different brands. My GF4Ti is Winfast (Leadtek).

And as I said, ONLY FOG slows my card down - and even on ancient games with system requirement way below my specs by every aspect!

On the other hand, as long as there is no fog in the gamescene, my framerate is very smooth, even on recent games with high details!
=> which means that this is not due to a weak config (like I said, even fog in old games brings my card to its knees). And this is not due to my windows/video drivers settings either, I've tried everything, including enabling/disabling "fog table emulation", among hundreds of other different settings...

So I conclude that I have indeed stumbled upon an issue outside the reach of science, as it seems beyond the scope of even the most ingenious of computer experts This is very frustrating..

SOS anyone! Getting to the bottom of this mystery will call upon wizardry I guess, as science seems powerless against it

Well, after reading your extremely long post, and your second, along with other peoples recommendations, I was a bit stumped at why someone didn't suggest one thing...

Have you attempted to uninstall/reinstall Direct X? Direct X handles most of your "graphics" capabilities of your card, such as Pixel shaders, vertex rendering, and yes, Fog emulation/rendering. I'd more than likely say that this would be your best bet into looking towards

Microsoft's Direct X Homepage

First, I'd try that. Then if you have access to it, try a different video card, such as someone elses GeForce 3 or 4. If you still have the problem, I'd imagine it lies somewhere in your setup, I don't exactly see how it could, but there's a chance. Just remember this saying, "The unthinkable is always possible, specially when it comes to computers".

A good friend of mine told me that, and I'll remember it forever.

Also one thing to check. I'm not sure this will fix the problem, but it's always possible. Try disabling fast writes in your BIOS. I had a friend that had slowdown issues with a GeForce 3 in the original Unreal Tournament when the redeemer's explosion textures showed, that seemed to help the problem to a point, maybe it'll help you.


Hope this helps.

Originally posted by IceBreaker

Running (more) benchmarks will be pointless - each 3Dmarks tests run smoothly and the overall 3Dmarks score are good. but of course, there are no "fog tests" with these benchmarking apps.

benchmarks? who said anything about benchmarks?

AoD - unfortunately, a spare Vcard I have not, nor do I know anyone who has one. I could try some games on their system, but since theirs is radically different in configuration, this may not be of much help


However, as 4 DirectX, for one thing I have never downgraded my dx version (besides means uninstalling dx, which cannot be done automatically, as this calls for sifting through reg entries and sh*tloads of files on the HDD ).
I have always gone from one version of dx to a higher one. The fog issue has hounded me from my first dx version (dx7) all the way to my present, dx9.0b one!

And every dx setup to this day has gone without a flaw, and 'dxdiag' has always shown a 'no problem' status! So I doubt the issue could be dx-related.

But if, despite what I just said, U still think I may have to revert to a previous version or just do a reinstall of my current version, I will have to know how to COMPLETELY remove dx from my system.

-> but then again, according to what I've said about dx (the fact that I've had no dx setup/diag problems), what makes U think that it could still be dx-related???


This leaves the BIOS fast-write option. True, I never considered that. And I even recall a friend deeming this option "superfluous"! (though he never said it could even slow down performance..)

That's a good idea worth trying. But not now. It's way past bed-time back here in Europe *yawn*. I'll try it tomorrow and report back the results.

Anyways thx for your help!



redwench>

benchmarks? who said anything about benchmarks?

??? U mentionned 'sisoftsandra' which is a well-known system benchmarking tool, isn't it??

it has some benchmarking units, but its primarily a diagnostic suite.

AoD>

OK disabled 'fast write' in BIOS (and made sure it was disabled once in windows..) - to no avail

Actually the problem was never with the fog display (it showed properly, in full detail) but only the speed at which it displayed. I could actually count the number of frames/second, esp. when I was close to the fog/explosion!!

U also mentionned vertex & pixel shaders, but these were fine - I have these 2 options in "Incoming Forces"and when I switch them on/off, I can see the difference graphics quality. And enabling these improves the quality, yet does NOT seem to slow down my card.

Besides even in OLD games (where vertex & pixel shaders are not used) fog still slows own my card - a lot.

And of course enabling/disabling fog table emulation changes nothing..

ONLY FOG is the problem!?!

As for directX, as I said dxdiag has shown me no problems with it, I have dx9.0b but the "fog slowdowns" occurred regardless of dx version: dx7, dx8, dx8.1, dx9, ... (And besides a complete uninstall of dx is nearly impossible)


So the mystery gets deeper. Know of any sorcerer who could help?

But anyways thx 4 your advice!


redwench>

Downloaded SisOft Sandra 2004 and gave it a try.

Actually, it's mostly a bunch of benchmark tests, and the rest are information modules. The benchmarks showed good above-average results (CPU, CPU multimedia, memory, cache...) and I even ran the "performance tune-up wizard". Needless to say, this didn't fix my fog problem..

Well, it would be a good idea anyhue to downscale directx with your card. It is directx 8.1 compliant, so your games aren't gonna run smoother with directx 9 and in some (rare) cases it could give problems running a 8.1 compliant on 9...

Uninstalling directx properly can be done with a directx buster. They're scattered all over the net.

Other then that it will be guessing... You could try lowering your memory freq. or playing with your AGP aperture, but it will probably help nothing.

I know what your going through I've given up on my weirdo problem ( [URL=http://www.opentechsupport.net/forums/showthread.php?s=&postid=176785#post176785]) It's frustrating as hell, but it fills your days now doesn't it

Ow and another desperate thing you could try is downscaling your PSU... Damn I wish my car had that many horsepowers hiyaaaah!!!!
(of course this is a stupid joke and even though the lack of humor in it might cloud that, I will not be taken responsible for people actually trying it )

Good luck finding your Merlin...

hehe - good one about the "downscaling the PSU"

Yes perhaps my card is chocking on the excessive power it is being fed

I know what your going through I've given up on my weirdo problem ( [URL=http://www.opentechsupport.net/forums/showthread.php?s=&postid=176785#post176785]) It's frustrating as hell, but it fills your days now doesn't it

Interesting topic - though I've seen similar issues. And it seems (though I may be wrong) that suggestions have been forwarded that U haven't tried yet - lowering RAM freq, switching 2 a stronger PSU, booting without a PSU (I made that one up )


As for AGP aperture, as have set it to match my Vram: 128Mb. That should more than suffice, and it does not explain the fog slowdown on old games that only require 32Mb Vram on highest details...


So reinstalling directx is the only thing left to do - though as I said, I don't see how that could change anything!

well, it might, but it shouldnt. some of the games scheduled out shortly will require 9 or higher, so even if it works, it wouldnt be a long term solution.

i would be surprised if sandra showed anything of interest for you, but odder things have happened. im not familiar enough with that particular aspect of graphics to be of any use, but ill try to find someone that is.