Stutter Fix? Railworks America

[ightenhill]

Theres very little point (if any) comparing one piece of software to another.. In the end the problem relates to the way the game engine is optimized and we know that RW does have shortcomings..

We are lucky I guess in one respect that we still have a sim with an existing dev team who do appear to be working on aspects of the core.. We can only wait with baited breath as to what Adam and Derek are talking about when they hint at improvemnts that may help with the stutters..

[pilot37]

Theres very little point (if any) comparing one piece of software to another.. In the end the problem relates to the way the game engine is optimized and we know that RW does have shortcomings..

We are lucky I guess in one respect that we still have a sim with an existing dev team who do appear to be working on aspects of the core.. We can only wait with baited breath as to what Adam and Derek are talking about when they hint at improvemnts that may help with the stutters..

I compare with other software because everytime I discuss a problem the blame shifts back to my PC. I have been a PC games player for years and particularly like simulation games which can be enhanced like Flight Sim, rFactor, Railworks etc...these sims tend to be more demanding on graphics and CPU. As a result I am relatively experienced compared to the average customer and I usually build my own rig and am competent at problem solving and experimentation. I also make silly mistakes, don't we all. I think on my powerful system my hard drive is the weakest link so I am updating it. I can also feedback how I got on. If I was successful then I will be one of the few people on here who can specify their rig, settings and a smooth unstuttered performance. I am not confident, but I am trying!

[RSderek]

Hi,
One of the big issues that I see with the sim is that at any point you can stop and and add more to the scene.
Not only that but there is not a limit on what can be added in the object filter list.
Even a small route can take ages to load if it has hundreds of assets added (all of which could have many many hi res textures)

The more added the more your computer will struggle.

It is just something to keep in mind if you are making a route, you don't have to use all the colours in the box, so to speak.

regards

Derek

[pilot37]

Hi,
One of the big issues that I see with the sim is that at any point you can stop and and add more to the scene.
Not only that but there is not a limit on what can be added in the object filter list.
Even a small route can take ages to load if it has hundreds of assets added (all of which could have many many hi res textures)

The more added the more your computer will struggle.

It is just something to keep in mind if you are making a route, you don't have to use all the colours in the box, so to speak.

regards

Derek

I'm sure thats true but my problems are happening out in the countryside before I even reach Lockerbie, and this is payware after all. I will wait now until I fit my solid state drive, then there can be no excuse

[Kromaatikse]

Interestingly, I actually sat down and made a FRAPS benchmark run of the entire WCML route (breaking rather a lot of speed limits in the process).

OpenOffice then refused to load more than 65535 lines of it, but that gave me data for the first 1100 seconds or so of the run - enough to include a pass through Carlisle, past Kingmoor, Gretna Jn and probably Lockerbie. Some serious formula writing later and I got some graphs showing maximum, minimum and average framerates over 10-second windows.

For large fractions of the time, even on the relatively open and sparse southern section of the route, the 10-second minimum framerate is about 20fps. On these same sections, the 10-second maximum framerate can reach 150fps, and the average rate is 60fps or more.

There are dips to 5fps in at least three places, which are doubtless associated with scenery-loads for the more intensely populated tiles. There are also noticeable troughs where the average framerate dips considerably, including through Carlisle station and what might be Lockerbie.

Changing the graph to show 2-second windows demonstrates that there are, at about 100mph, regular sharp dips in the framerate about every 10-15 seconds. The maximum framerate also drops out at many of these points, showing that although the scenery loading is spread across a number of frames, it still has a severe impact on performance.

I think what must be happening is that fresh copies of each used asset are being loaded, decoded and instantiated for each tile, if not each object placed on the tile. This would certainly explain the high memory usage as well.

[bigvern]

Less scientifically perhaps, but when I was testing the Manx route for Phil a few weeks back, I enabled the built in FPS indicator. The see-sawing of the frame rate up and down was constant, anything from 10-12 FPS right up to 80-90 FPS then back down, up and down all the time. Again, I'm only a layman but I do wonder if a frame rate limiter would help with this? Could it be the game engine is not optimising the display rate, getting up to the 80 or 90 mark going, "Oops" (yes it actually says oops), "Can't keep this up, back to 10 FPS" then at 10 the opposite kicks in, "Phwoar yeah, let's go baby plenty of memory" and thus the cycle repeats.

Whichever way you look at it the code is desparately in need of some optimisation and if I were Paul Jackson (which I'm not) I'd be on the phone to Kuju CEO exclaiming, "Oi, get your best programmer down here now to sort out this pile of crock you landed us with."

[djt01]

The see-sawing of the frame rate up and down was constant, anything from 10-12 FPS right up to 80-90 FPS then back down, up and down all the time. Again, I'm only a layman but I do wonder if a frame rate limiter would help with this?

If the frame rate on the machine you were testing on regularly dropped down to 10-12 fps then I don't see how a frame rate limiter would be of much help.

Usually for a frame rate limiter to be effective the frame rate is forced/limited to the lowest consistent speed that the machine can maintain in a particular game. If the fps are dropping that low (10-15 fps) it's just about unplayable.

Whichever way you look at it the code is desparately in need of some optimisation

From the looks of things it might be better to abandon the current game engine all together before anymore new features are added. I don't know how bright the future is going to be for RailWorks if it continues to use a game engine that seems like a dead end street.

[StPancras]

Hello

I have read many posts detailing problems with stuttering, on machines with a far higher spec than mine. I built mine about 3 years ago, and apart from a new ATI HD4850 card, I haven't replaced anything. So it's pretty unremarkable.

It looks like this:

Core 2 Duo E6400
Gigabyte P965 MB
2GB Patriot Dual Channel DDR2
ATI HD4850
Couple of Samsung Spinpoints
Windows 7

I get hardly any stuttering, I run full details, with most options on. So what do I do differently? I have a good quality Sandisk 8GB Flash Memory Key set for Readyboost. It seems to work for a number of apps, including RW. It's a bit cheaper than replacing your hard drives with SSDs.

[RiscaStation]

Hi,

I think its a question that should be put to Rail Simulator.com, after all they have never revealed what specs they used to check or develope the game on.

Regards
Mike

[bigvern]

If the frame rate on the machine you were testing on regularly dropped down to 10-12 fps then I don't see how a frame rate limiter would be of much help.

I did wonder that actually but my logic was if it's the constant maxing out of the hardware which is causing the see-sawing, then by limiting to (say) 40 FPS it might prevent the overload occurring and a more consistent rate. I would settle for a constant and steady 24 FPS which is I believe is the optimal speed used for cinema projection so the eye sees the image as a fluid moving picture rather than a series of stills.

[ightenhill]

I guess that would depend on the architecture of the draw section.. If , as would appear, its very cpu fixed its till going to pause even if held at 24fps because it simply cant do anything else in the cycle but make a call to load the next piece etc..
I agree the best bet is to have a whole new engine but it would be interesting to see if better memory management in the current engine can actually improve the issue..

By the way the 24fps as a cinema reference is a little more complicated. Each frame gets projected twice through the shutter as it passes through the gate in the projector. Its this effect that causes you to see no gaps (known as critical flicker fusion) if you run 24fps without this passing element duplicating each frame every second it does indeed look flickery.

[pilot37]

Ok, so I was up till the small hours last night with my new Solid State Hard Drive installed and checked with Crystalmark 64, set up large virtual memory. I installed steam / Railworks on it and tested it out on WCML North and Isle of Wight (I always test my graphics on the Tornado scenario too check for improvements / problems). And the result.....

Not the slightest bit of difference whatsoever!

Not a thing! And still crashing half the time 3.9 miles out of Lockerbie.

I don't suppose the folks at Railworks have any ideas...surely their machines didn't just switch on and work first time. What else is vital / needs to be checked? Come on, give us a clue!

[RiscaStation]

Hi

"Come on give us a clue", I think you would be lucky to get a satisfactory answer to this.
I envisage a reply saying "it's on our to do list" and will not materialise.
Three years on and still problems, unbelievable.

Regards
Mike

[RSderek]

Always good to have a to do list, keeps us busy and has done for 3 years.

RS.com, Keith and our beta team did not have the crash in that location, if we did we would have looked into it.
There have been a hand full of dmp files sent to us and we are looking to users issues.
As usual if you have a problem make sure you email Support.

best regards

Derek

[msmith4000]

I can give you two data points.
On both machines, adjusting the settings of the graphics card - from resolution to antialiasing - makes essentially no difference. I could probably downgrade to my old X1950 or 8800GT without seeing it perform any worse.

Yep, the game engine is inefficient in that it does not efficiently use the available CPU power in you computer, the game is limited by the CPU. That is why the game runs the same speed no matter what graphics card you run, and additionally why SLI does nothing to improve performance. The graphics engine of the game is not that demanding, a mid range card is more than sufficient to render the graphics. The problem lies in large amount of physics calculation the PhysX engine portion of Railworks needs to carry out for each individual loco and carriage within all the consists that are currently in the scenario. Even a short consist of one loco and 4 wagons requires huge amounts of calculations, that coupled with the fact thatthe game engine only uses one core of your CPU is why even the highest end CPU's struggle to run Railworks, especially on the bigger routes such as WCML. Bigger routes will naturally tend to have more consists runing in them.

I'll bet the work derek is hinting that RSC will be working on is a way to make the PhysX engine work over multiple cores, splitting the work equally betwen them. Or even better and probably easier to implement, they will be shifting the PhysX engine used by Railworks over to the CUDA based PhysX SDK so that the calculations can be done on the Graphics card watch this space and get ready to buy yourself a NVIDIA graphics card! (Am I correct Derek?? )