Atomic Systems

There's lots of info floating around regarding how TS2015 uses the CPU, RAM, and GPU. I redd somewhere that TS2015 uses mostly the CPU, and not even multiple cores. So I'm not sure WHAT'S happening here! I also redd that some people were able to force TS, (I donno which version), to take advantage of a high-end GPU, (or any GPU, I guess) to get the sim to run better. But I can't find anything about this anymore. Does anyone know anything about this? Or does anyone here know what processor TS can be made to use?

The game uses whatever processor it finds, that's why it runs ( stumbles/crawls/lurches along) on the multitude of systems we have. Your question should be
"what settings would you suggest to enable this PC <insert system specs> to run the game smoothly"
There is no right or wrong answer, but you'll get plenty of suggestions and maybe even some explanations as to why.

Jim Backus
Its all about balance you need to balance the motherboard, power supply, RAM, dedicated SSD or fast HDD, video card, cpu, monitor(s) [size] and OS - (the latter should always be 64-bit). (From tests I have carried out Windows 10 preview runs TS2015 very nicely.)
On a well balanced system TS2015 cpu usage is around 30/35% and ALL 4 cores in a quad system are used - albeit 'core 0' predominates. (The lower the cpu specs the more that TS 2015 will use its resources - that's just the way code is handled).
The video card needs two major items (talking about NVidia here): 1) memory bandwidth the higher the better and it MUST be above 60GB/Sec to see TS2015 run well, and 2) VRAM - TS2015 uses a lot of VRAM and its wise to use a card with at least 2GB onboard if you have a decent size (>22") or multi monitors, anything above the GTX 75x series would do.
Using Intel cpu's - I would use either a 3rd/4th Generation i5 or i7 cpu and its a bonus if the chip can be overclocked and the motherboard must be of reasonable quality to optimize any overclock..
The SSD provides faster loading of the game and also minimizes the tile boundary lags which TS 2015 is prone to ie it minimizes hard page faults.
I now advocate 16GB of RAM - fast low latency matched to the mobo as this reduces any access to the paging file and also reduces wear and tear on the SSD.
I recommend a GSync monitor (the smoothness is incredible even at low indicated frame rates) and the new 4K monitors are showing promise.

If you are lucky all this will work fine, and yes you can get away with lower specs - but these are the things that I know will work.
Since TS 2012 I have found that running a well cooled cpu around or over 4GHz does help if you want all the settings in TS 2015 full right.

What the above may not resolve is shimmering on the overhead wires, rails and upright gantries, or moire on the points, but these will vary from route to route.

So go for balance and TS 2015 will perform fine.
Regards
pH

Peter, Windows will always show all available cores being used as it switches between them to balance the load. The game is predominantly single threaded (core 0 usage) with several 'helper' threads that are run on any subsequent core. Rather than being multi core enabled
it's multi thread enabled, any extra core usage we see is due to the OS , not the game.

Gary
IMO it is multicore enabled - in TS2012 there was an option to invoke multicore.
If you want to see what it looks like running on a single core just use task manager to set it to use only one core - its glacial.
It was dropped in subsequent releases and when I wrote to RSC (as it was then) I was told the switch was no longer needed and it accessed multi cores as required.
However it is NOT a true multicore app! There ain't many of them around!!
I thought most games were only single thread ??
As ever
pH

Yes Peter
the game (like most) is mainly single threaded, I took your post as an assertion that the game itself was written to use all available cores. Apologies if I got that wrong.

However, your post asserts that the game is coded to use 4 cores, when in fact the reported core usage is down to the OS

There's an odd belief that a multi-core app has to use 100% of all cores....rowlocks, to borrow a term from the boating fraternity. If it uses, or is written to call for, the resources of a second core it's a multi-core app.

.

Gary
When I say "true" multicore I mean something that has been written entirely with parallel code specifically for multicore use, and that is quite rare in all software fields.
IMO TS2015 does use multiple cores ie it is termed "Multicore enabled" which means, to me, that it uses some multicore features but not to the rate that a true multicore would.
I agree with you, a multicore program does not have to use all cores all of the time, and I don't believe that a parallel coded app would be any more efficient than say a serial coded app or a combination of the two. I was merely making the point that a good quad core will run TS2015 much more efficiently than a duo core of the same supposed cpu "speed" and that in essence TS2015 is allegedly only a single core app. Now whether its Windows allocating the cores or TS2015 coding also gets involved, doesn't really matter, as the more cores you are using then the more efficient the throughput of data.
As you know I use a piece of software called Process lasso (which allegedly allocates core usage "better" than Windows) and that has given me a significant smoother experience in TS2015 even at quite low frame rates.

But to go back to the OP - balance is the key!
pH

The best way to make a single threaded game simulator like Train Simulator to run smoothly - as in a roughly constant number of frames per second - is to use the command line option -FPSlimit=xx in the game properties in Steam. The more assets and actions appear in a videoframe, the more CPU and GPU computíng is needed to complete it. This is largely determined by the route builder, assets and scenario creators, but can be tailored for a specific PC configuration by fiddling game play and graphics settings in game.
Without the FPSlimit, the game will try to run as fast as possible i.e. at 100% of a processor core. The operating system will schedule the game on the first available core, which will cause it to be move between them, when more than one is available. However, some system services like reading data in disk files are handled by asynchrones devices drivers, while the requesting process must wait. railworks.exe calls a few other Train Simulator specific processes, mostly Steam. I also communicates with the Steam server, unless running in off-line mode.
Synchonization is the great monster in the box; causing proccesses to do nothing while they wait for other processes or I/O. If file data are cached in unused extra RAM (on a 64-bit OS), data can be read much faster. What prevents a game like TS2015 from employing all CPU cores is the difficulty of splitting the work of a train simulation into independent sequences of operations, that can be performed in parallel.
It comes down to this: how much work can the sim accomplish in a time step. The length of a time step is roughly 1 divided by FPSLimit seconds. Thus with -FPSLimit=25, 1/25 = 0.04 seconds. Some time will be lost to synchronization, so 24 FPS will be a likely result. Adjust limit to your system and its settings as you see fit. The is no one short set of directions, that will fit all cases. We could probably train a neural network to compute pretty good tuning suggestions, if we registered engough systems, configurations, settings and performance.
I would pick a dense route and a busy scenario, then drive it with FPS display on and make note of the lowest frame rate observed. Then adjust graphics and game settings to reach a frame rate, say >25. Lots of driving the same scenario between adjustments to get it right. Finally, insert the -FPSLimit=26 in Steam properties undet Set Launch Properties in Train SImulator. Or:
State your system specs, settings and prefered routes. Some ideas are bound to come up.
Keep a seperate boot for Train Simulation if possible. Tune it to start only the services including antivirus required for train simulation. The less stuff is running in background of the sim the better it runs.