PDA

View Full Version : Does HL2 allow triple buffering to be enabled?


Idoru
11-16-04, 05:58 AM
Just curious - my Doom 3 experience was somewhat borked by the inability to get good enough framerates on my 6800 Ultra with vsync enabled at 16*12... triple buffering would have sorted the problem, but of course nvidia no longer supports it in the drivers. However, I understand it can be enbled if the game has the option built in? Thanks.

tobit
11-16-04, 06:03 AM
I'm not saying your wrong (re: triple buffering) but i'm pretty sure there are many people who have 6800 Ultras that didn't require triple buffering to have a good d3 experience. Have you looked at other parts of your system? Enough ram, cpu fast enough? A little configuration goes a long way :)

Idoru
11-16-04, 06:41 AM
*Ahem*... well I guess 'good' is subjective; anyway 'consistant' might have been a better choice of words... no problem with my spec: A64 3500+/A8V mobo, 1GB Corsair RAM (2-2-2-5, 1T enabled), dual WD Raptors in Raid 1... I also have the game tweaked up via an autoexec.cfg... what triple buffering would eliminate is the 'stepped' drops in framerate I get when fps drop below the refresh rate (72mHZ @ 16*12 on my system); ie 31fps, then in some very rare instances 16fps... with vsync off and fixedtic set to -1, I can hit 200+ fps in places... however, I have to put up with noticeable tearing. So a trade-off is involved that, given the hardware involved, is slightly irritating. Hence the query re HL2 - triple buffering would allow me to play with vsync enabled without framerates tanking. I ask the question because I've yet to pick up a copy of the game (got to finish D3 and Halo 2 first), so I can't rummage around in the console to find out for myself...

saturnotaku
11-16-04, 06:44 AM
Doom 3 was programmed to run at 60 fps. The fixedtic adjustment screws with the animations and other things that were designed with the cap in mind. Turn vsync off, revert back to the frame rate ceiling and you should never drop below 60. That's what I've done on both a 6800 Ultra and an X800 Pro and it's worked flawlessly across all resolutions.

Idoru
11-16-04, 07:37 AM
Fair point saturnotaku, though I've yet to see any screwed up animations/problems with fixedtic off... the framecap was originally conceived with MP in mind as I recall, and got carried over into SP... unfortunately I find my eyes are very sensitive to framerates below 60fps and gameplay very quickly lacks smoothness, hence the decision to remove the cap to maximise framerates at all times...Anyway, back to the original question - can you enable TB with HL2 using nvidia hardware/drivers?

Slammin
11-16-04, 09:02 AM
Were you enabling vsync in-game, or were you instead using refresh rate override? If the latter, that is a driver bug.

I just looked and do not see an option for triple buffering. HL-2 0wnz btw!

Idoru
11-16-04, 09:39 AM
Thanks slammin - glad HL2 rocks! To clarify, I set the in-game refresh rate via my autoexec.cfg, so if the frame rate cap is removed, I can get 72fps max @ 72mHZ with vsync enabled. So no bug I guess...

SmuvMoney
11-20-04, 02:34 AM
I could not find it either. It slightly spoils what has been an otherwise great experience so far. I hope Valve plans to fix it in the next build/patch.

superklye
11-20-04, 02:48 AM
What, exactly, does triple buffering do (besides sound cool)?

StoNer
11-20-04, 06:39 AM
A buffer is where data is stored. In games its a single frame. In double buffering there are two buffers one front and one back, and they switch. As frames are loaded into the back buffer, the front buffer displays the image and then they swap again and the front becomes the back and is reloaded with a new frame.

Triple buffering adds an additional back buffer. The good thing about this is if the gpu finishes loading a frame into the buffer before the monitor is ready to display the frame ahead of it, the gpu can use that time to start working on loading the third rear buffer with another frame.

The time saved with triple buffering means around every 4th frame or so your gpu will have completed every request already. The result of this is a large increase in the frame rate deduction caused by vsync via double buffering. As in if you were getting say around 30fps at 60hz you could instead get more around 45fps at 60hz with vsync.

Makes me wonder if they could do like Quadrupil buffering for dual display systems o.O

StoNer
11-20-04, 08:41 AM
Some people say the quad buffering in the FX and above cards is enabled by default and some say it isnt. I havent found a way to force quad buffering yet.. But if you download the nV tweak utility nVhardpage you can enable triple buffering.

I forced on vsync and threw on doom3 and enabled vsync thru the game aswell.
My fps were anywhere inbetween 30 - 45 and 60

when there was alot of movement etc i was around 30 and when i stood still it would go between 45 and sometimes stick at 60fps.

So i might be wrong but i think its automatically switching between double triple and quad buffering on its own.

Or maybe quad buffering only sees a performance increase after a certain amount of frames and then drops back down to normal for a certain amount..

I dont know really because i havent been able to find any information on how quad buffering works, and how by default nvidias cards utilize quad buffering.

maybe someone who knows more or is better at finding answers at stuff like this can explain more.

superklye
11-20-04, 12:01 PM
Thanks for the explanations. :)