Hello all,
I'm new to lfs, trying to get it set up on my new PC. I think I will really like this game, but I need to get it working first.
My problem is that the graphics are choppy, even though the fps counter never drops below 75, and usually runs just over 100. I've tried messing with most of the graphics settings and re-testing but nothing seems to change it. V-snyc, fps limit, LOD sliders, it always looks exactly the same.
My hardware shouldn't be an issue. I have an HD6950 2GB video card in an x16 slot, running a bezel-corrected Eyefintity three display setup. CPU is a C2D at approximately 2.2Ghz. 4Gb dual channel RAM running at the FSB speed of 266Mhz. Win7 x64. With all in-game settings at high, my CPU runs at 50% load (combined, 40% CPU1 60% CPU2). Oddly enough if I turn everything down, AA off, etc. my CPU runs at about 60% load. Still has the same choppy effect though.
I'm running the latest drivers and I downloaded lfs a few days ago so both are up to date. Hopefully someone has some ideas!

Have you tried setting the affinity to just one CPU core for the LFS process?

http://www.addictivetips.com/w ... n-application-in-windows/

If you're getting over 50% load on both CPU's, then there is definitely something else running on your computer. LFS currently doesn't use more than one core.
Try to set FPS limiter in LFS to the refresh rate of your screen and check if the CPU usage goes down.

Hi,

I had the same problem to but only when i run LFS windowed.
In LFS it shows 250 FPS but looks and feel like 10.

I run LFS now full screen with 150 a 220 fps and it looks and feels good now.

I have a Radion HD6870 with Eyefinity 5760x1080 (3x 1920x1080). ( i Dont use the bezel correction in CCC but only in LFS/iracing)
PC is a AMD Phenom II X4 with 4Gb mem and Win7-64.
CPU load is about 65% (on core 1)

So check if you run LFS Full screen and not windowed. Or maybe install the latest drivers for your 6950

lfs' graphics are updated at the physics loop steps which runs at 100hz
unless you have a monitor that supports 100hz or multiples of it (basically only supported by crts) which is unlikely as most run at 60hz some microstuttering is unavoidable

Thanks for the replies. I don't think I am running in window mode, I don't see a window anyway. I also can't find an option in the game for windowed mode.

Here is what my CPU usage looks like when running lfs:


When I use affinity to limit lfs to one core, one core goes to about 90%. It doesn't change how it runs though.

I've already tried limiting the frame rate, but it didn't work. I did notice this time though that enabling v-sync helped with the stuttering. It's at least to where I can tolerate it now. But I still have bad bluriness when stuff moves across the display. When I am going straight at something, it looks really great and crisp. But in corners or when things go past you things get really blurry and it kind of gives you a headache.

Quote from Shotglass :

lfs' graphics are updated at the physics loop steps which runs at 100hz
unless you have a monitor that supports 100hz or multiples of it (basically only supported by crts) which is unlikely as most run at 60hz some microstuttering is unavoidable

Worse still, some monitors offer (or are limited to) 24hz at Full HD resolution, so make sure you've got at least 60hz selected in Options -> Screen.

If it was me I'd go back to basics:

open LFS
set the graphics to the minimum as shown here http://en.lfsmanual.net/wiki/File:Graphicsmin.jpg
set your FPS cap to 60
go to single player, press t and type "/clear" then press return - so you have no cars on the grid
join the grid in any car, and start the qualifying/race
drive a couple of laps and see what the cpu usage is like

To switch between windowed and full screen use shift + F4.

Quote from boothy :

If it was me I'd go back to basics:

open LFS
set the graphics to the minimum as shown here http://en.lfsmanual.net/wiki/File:Graphicsmin.jpg
set your FPS cap to 60
go to single player, press t and type "/clear" then press return - so you have no cars on the grid
join the grid in any car, and start the qualifying/race
drive a couple of laps and see what the cpu usage is like

To switch between windowed and full screen use shift + F4.

agreed, you need to go way back until you have the desired performance. change one thing, test. if there is no decrease in performance, change settings again. keep doing this until you hit problem again. it should help you narrow the problem down quicker.

I guess that's part of my problem though and why I posted here. I haven't been able to get satisfactory performance, even on the bare minimum settings. With everything at minimum it still looks blurry in turns, sharp as a tack straight ahead.
The only thing I don't have at minimum is Z buffer depth because 16 bit makes it look even worse.

And I do have 60Hz monitors.

what's it like with only one monitor?

It's the same. Guess I just have to work on ignoring it, maybe a new driver from ATI will fix it, since my card is relatively new. Thanks for the input.

Afaik, this stuttering usually occurs in Crossfire/SLI configurations. Are ur other PC components healthy and on the same line with the GPU?

Ok this is still driving me nuts. I have uploaded some pictures to try and show what is going on. These screen shots are all at 60+ fps.
http://www.imsolidstate.com/wp ... t/uploads/2011/04/017.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/018.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/019.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/020.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/021.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/022.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/024.JPG
http://www.imsolidstate.com/wp ... t/uploads/2011/04/025.JPG

I think this is an issue with my video card. There are posts all over the web with stuttering on the 6950s. And it's not crossfired.
I tested LFS on my "old" computer and it worked great. AMD 64 4000+, 2GB RAM 400Mhz DDR, Nvidia 7950GT on a PCIe x16 v1.0a, and a VGA connection to a 42" TV that is resolution limited by the VGA port to 1280x1024. I don't have a HDMI adapter so I can't test 1920x1080.
I'm thinking about trying my 6950 on my old machine to see if it still has the problem, and maybe my Precision 390's MB is causing some issue.

I've tried all of the settings that are available to me, both in game and out. I have figured out that setting AA and AF in the Catalyst control panel works better than the in-game settings. Other than that, nothing else has helped. I read somewhere where a person fixed the issue by disabling the video card HDMI audio, but that didn't work either. I'm starting to think I need to return this card for Nvidia. The only people that don't seem to have a problem with this card are running quad core 4Ghz CPUs.

At any rate, if I don't get this fixed I'll be really annoyed because I just converted everything in my custom-cockpit over from Forza 3 multiscreen (which had incredibly smooth gameplay and proper side screen renderings) to PC because of games like this one. I've found that LFS is the only game though that doesn't stretch the side screens awful. I tried GTR Evo and it's awesome but the side screens make you sick. Rfactor is even worse. Dirt 2 and shift 2 are fun but they do it too. I'm not sure if I should go back to single screen or back to Forza.

> that is resolution limited by the VGA port

Erm. Limit of VGA is 2048x1536.

Yeah but not on my TV. It's a Viera, read the manual. http://service.us.panasonic.com/OPERMANPDF/TCL42U12.PDF
Max resolution supported on the VGA link is 1280x1024. You need an HDMI connection to go 1920x1080.

Its looks like its in 3D mode. Maybe its beter with a 3D glasses

How are your screens connected? DP port? or do you use a active DP to DVI cable? What driver version for your HD6950 do you use?

Hi imsolidstate,

I think i found the problem.

I think you are using the AA/AF settings in CCC (Catalyst Control Center) and have set the "Anti-Aliasing Mode" to Super-sample AA.

I have in game (LFS) set the AA and AF to none and use only the AA/AF settings in CCC

AA 8X and no Morphological filtering
AA mode to Multi-sample AA
AF 16x

LFS looks OK for me now but when i set Morphological filtering on its looks like its a bit choppy.

When i set the "Anti-Aliasing Mode" to Super-sample AA its look like the pics in your other post http://www.imsolidstate.com/wp-conte...011/04/022.JPG

Try the following settings in CCC maybe it works for your HD6950 to.

AA 8X and no Morphological filtering
AA mode to Multi-sample AA
AF 16x

Similar things happen on my old legtop in window mode, but on a new PC everything seems fine.