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A little time digging - Flickering problem

Posted: Sun Dec 11, 2011 7:42 pm
by firetrap1
Has anyone ever been running railworks when suddenly, the controls for the loco/train you are driving, lock-up and the cab view starts to flicker rapidly?... This happened to me recently so I started digging into the problem, bearing in mind that this may happen even when you are running at a steady 25-30fps.

I have now been able to recreate the issue on demand through a bit of scenario creation and have saved a screenshot of the performance from my MSI GTX 560N graphics card (see below).

Image
(this is a screenshot taken after having passed through the station with extremly high levels of AI and custom scenario scenery)

During the test Railworks was running at 30fps along an unpopulated section of the WCML (south of Carstairs). The closer my train got to the station at Carstairs the worse the issue got. Now this is not to say that there is a problem with the WCML North route. Far from it. Let me be clear in that I believe this issue has more in the way to do with tile loading than any other issue. On the left side of the image (highlighted in the box in orange) is the Memory usage of my graphics card. Flickering and control lockups seem to occur when railworks loads tiles, resulting in a huge 'jump' up in memory usage. The flickering issue will then disappear once the tile information is dumped by the game engine.

Now the strange thing is that when driving through highly populated sections of the route, i.e. Motherwell and Glasgow, I cannot see this issue repeat itself. Upon reviewing the logs from my graphics card there is no big leap in memory usage, just a steady increase over a few minutes. So it seems like the control lockup/flickering issue is caused as a result of big jumps in my GPU's memory usage. (GPU load and processor load both remain stable throughout the test).

Has anyone else came to the same conclusion???


regards

chris

Re: A little time digging - Flickering problem

Posted: Mon Dec 12, 2011 9:19 am
by nsupersonic
I have noticed sometthing similar on a route I created and on all routes available on payware. I make this quite clear - It has nothing to do with the routes themselves and has been like that since the days of rail simulator. Again being no fault of program design

I found the the fault lies with what I want from my computer and found ways of removing it or reducing the effect.

1. Anything above a 23 inch monitor at full resolution, needs a serious (but not wastefully over the top) graphics / CPU combination to eliminate the effect -
2. Or reduce the maximum resolution of a larger monitor and run it not full screen, as mentioned elsewhere.
3. Refer to very helpful Computer Requirement Help topics on UKTS


Charles

Re: A little time digging - Flickering problem

Posted: Mon Dec 12, 2011 2:35 pm
by Retro
Have just emailed support about this issue.
Kind regards James.

Re: A little time digging - Flickering problem

Posted: Mon Dec 12, 2011 3:24 pm
by nobkins
Some good investigating Chris. Please do email RS.com about this. I emailed them and they asked for some more info and a video if it could be provided so I understand they are looking into it. If you can replicate the issue and capture it ( a tall order possibly) then I think they would be interested in it.

Well done.

Jim

Re: A little time digging - Flickering problem

Posted: Mon Dec 12, 2011 3:25 pm
by bigvern
Can't say that I have had this, but I am still getting the subliminal flashes of black and white as if below or inside the terrain. Latest was on PDL driving the 4CIG, but it has happened on all routes.

Re: A little time digging - Flickering problem

Posted: Mon Dec 12, 2011 7:56 pm
by firetrap1
I have repeated this test again today using a custom scenario on WCML North. I had placed over 35 AI trains (each from a different provider in the flyout) and I had given each service it's own custom stopping point for every destination. Some of the services also used custom scenario specific destinations along the way.

The result was the same as previously described in my original post, however the flickering effect seems to have become more frequent. It would also be true to say that the points a long the route where the 'flickering/jelly cab' issue appears has changed also.

It seems to start when my VRAM goes over a specified limit (the card has a physical limit of 1Gb but issues start to occur after the VRAM memory usage increases over 920Mb). I'm not sure if this is an issue with my card in particular, but every so often my card will 'dump' all of the VRAM, and everything then returns to normal.

regards

chris

Re: A little time digging - Flickering problem

Posted: Tue Dec 13, 2011 8:16 am
by chrisreb
I have noticed this most (vern's issue which I am not sure is same thing) when running Dublin to Cork. At least once a minute when train running at speed so assume something to do with tiles loading. Happens when running at a good framerate.

Re: A little time digging - Flickering problem

Posted: Tue Dec 13, 2011 9:30 am
by NSWR67
Hi,

I had, yes that's had, this problem and could reliably reproduce it in the "Hand Over" scenario on WCML Nth route.

I tried all matter of things to 'free up resources' however what did it for me in the end was a simple "clear cache".

I've now been able to run any scenario in WCML Nth without the problem occuring.

I really hope that others gain relief from this problem via this often overlooked and simple task.

Win7 64X, i7 930, ATI 5870 1Gb, 12 Gb RAM, Intel 930 series SSD.

Steve.

Re: A little time digging - Flickering problem

Posted: Tue Dec 13, 2011 10:14 am
by nobkins
I have cleared cache many times since and this problem still occurs on occasion. I will try it again though. Thanks for the help.