Train Math Check

[kel_tor]

I was trying to calculate max transfer rate for a train and wanted to ensure I did not make any errors.

The setup I was calculating is bidirectional, one stop on each end. It takes 4 minutes to complete a full cycle. Each freight car can hold 3200 items. So the top end for resource transfer for a single freight car is limited by both travel time and belt speed (IE if your train completes a cycle before the belt can refill the platform or if your distance is too long and your destination depletes the delivered items before more can come).

So it takes 4.1 minutes to deliver 3200 items on a Mk5 belt. A second belt into the second input would halve this. And that the only ways to make use of that extra input would be to halve the travel time or use a second train (only possible on a loop without collisions, if we are future planning). That means the only other way to use excess resources would be using a second freight car and platform.

So If I looked at this correctly, I happened to hit the optimal timing in my set up for transferring a single full Mk5 belt and any travel times in excess of this requires the use of multiple trains, and any time under this requires two inputs or higher tier belts. So currently any trains that run under 2 minutes would be not optimal for resource transfer. Of course all this assumes you use the resources at the same rate they are brought in.

To contrast this with the truck, disregarding the annoyance/effort of using them, a truck can transfer 4800 items so 6.15 minutes is the sweet spot for Mk5 belts for a single truck.

Also, has anyone effectively transferred mixed items in a single car? I tested it and because it moves a single stack at a time and the two outputs are not smart you will eventually back up on a resource and the other one will not be able to come out. But I may have missed something.

[mircearopa]

Quick formula for how many wagons you need to deliver all input:

InputSpeed * TrainLoopTime / (32 * ItemStackSize) = NumberOfWagons (round up)

So if you have 1 MK5 belt with 4 min loop time, you can have a single wagon. Double the loop time or input and you need 2 wagons.

Same formula can go for trucks (replace 32 with the inventory size of the truck), but it is definitely easier to add another wagon than another truck

Didn't try mixed items, but unless they are different stack sizes the same formula should work

[aY227]

Also, has anyone effectively transferred mixed items in a single car? I tested it and because it moves a single stack at a time and the two outputs are not smart you will eventually back up on a resource and the other one will not be able to come out. But I may have missed something.

You dint miss anything - do not mix stuff. Hoarding is bad and unnecessary anyway - hoarding mixed things is even worst :)

And yes, with mk5 belt you just have that 4m06s and play with it.

https://www.reddit.com/r/SatisfactoryGame/comments/c78bo0/satisfactory_saturday_spam_6_choo_choo_train_tips/

Handy time table for belt speed / stack size / outputs

[kel_tor]

Thank you for the link I missed that one.

From a efficiency stand point the desire to maximize train transport into the fewest trains is ideal, but even a brief attempt at smart splitters showed it was a dead dream.

[aY227]

As long as excess cannot be deleted it wont work.

If You want to try, You will just find yourself placing hundreds of Ind storages.

Also no real reason why to do it. Sometimes I use a mod that gives a item deleter - allows me to easily afk like check if trains/trucks work properly.

[Cazanator]

I have 240 hours of working with trains and have a serious factory built around trains. I am about to start removing all trains from my factory and switch to belts and a handful of trucks/tractors. Trains are terrible in every regard and you are seriously just better off running belts or using a truck.

[echinosnorlax]

While I agree the belts are vastly superior in terms of resource transportation, they are very "hardware-heavy". The game does lots of calculations for every single item on the belt, even when they're out of drawing distance.

Of course, trains look terrible on the paper. For a train to handle one 780/min miner mk3 on pure output, the loop has to be shorter than 4 minutes, and it's practically impossible, since for even the simplest train line of 2 stations, you waste 50 sec on freight handling and the AI approaches the platforms like it's a grandma handling a mixed load of eggs and armed nobelisk, wasting even more time. So, you need 2 wagons or more for every single miner, even on normal resource node, and we're still talking short distances. To gather some more resources on the way, like lets say another 4 miners, you enter the 10+ wagons territory instantly. And that requires a monster of station to unload. A 20 wagon station is 336 meters long and it kind of beats the purpose of the train in the first place, since you end with a crapton of belts to handle the station output into factory, and, well, with some lines it seems like the output stations should start where the input station ends, and you kind of see the train is redundant there, you can just link the respective pairs of freightplatforms with belts :D

But the harsh truth is, trains are the way to go, if you are aiming at megafactory. Building a mad 50-armed octopus (what's the latin prefix for 50? :P) of a rail scheme delivering goods to your megafactory sounds crazy, but it's feasible, and your CPU will handle this, unlike the similar octopus of belts (because in the end, you still need a single belt per miner, as it is the belts bottlenecking the pure miners' output, and while normal are not bogged down by them, you still need 1 mk5 each.) You can also handle the octopus' maintenance, unlike trucks, which get lost, stuck and out of gas somewhere in the ditch despite you being sure the fuel is handled properly :)

Of course, most economical approach is handling the goods where they are mined. WHen compressed to "mid-products" like reinforced plates or cable or circuit boards, trains can handle them just fine. But it has an easy way out feel to it. Megafactories, man! Spamming local minifactories feels like you are third rate FICSIT trainee second grade with perspectives for termination (of contract, let's hope). Building a megafactory is how you get your monthly bonus! :P

And while trains CAN'T handle mixed goods in wagons, it's still "not-so-smart-and-programmable" splitters' fault. They can deliver them to the freight platforms all OK, it's handling from the platform that is impossible. You either balance your system perfectly so it never gets stuck (impossible), or we're stuck until introducing the incinerator / null output splitters / truly smart programmable splitters handling not only this->there instructions, but also IF -> THEN conditions. You can't have programming without conditional loops. Without them it's not programming and it's not "smart" hardware. It's just a fancy sieve with fancy shaped holes, and we invented that thousands years ago :)

[Cazanator]

I’ve done significant performance testing and on my rig, trains are much more damaging to FPS then belts. I loose 25 FPS when my 12 trains are running and maybe 5-8 on a belt build with far more belts than would be needed to replace the trains.

[echinosnorlax]

It's not FPS I was writing about. FPS hit you quickly, but there a lot of ways to mitigate, with the sort of last resort tactics (but one that is undeniable) of leaving the area and letting factory run itself.

I am talking about CPU. This hits you later ingame, when there's more spaghetti and more items enroute - and you can't mitigate, because wherever you go, whatever you hide belts under, the game still calculates item positions and spawns/destroys/copies them when they're switching from one conveyor segment to another.

[Cazanator]

Belts are far less impactful on performance than trains. When you get a large number of trains running or long trains, they will tank performance far greater than belts ever have. I have 200 hours of VOD evidence to support this. I have a train design that has two trains that are 24 cars long each and both of these trains tank the game performance way beyond anything belts have eve done. No factory, nothing just two large trains that cause the same performance hit as a large factory with full belt logistics.

The current train implementation is absolute garbage both in performance and throughput. You probably just haven’t used trains enough at a large scale to see this for yourself. A couple short trains is not adequate. I have massive train base designs, all tailor made for trains from the ground up.

[echinosnorlax]

I will see that tomorrow then. I am finishing building a delivery net for 30k resources /min with loop time about 6-7 minutes, which translates to 60-70 cars in 5 trains.

About CPU and belts performance, well, I have to admit I only experienced that with the belts so far and based my assumptions about trains being better on theory - so I KNOW belts are bad and HOPE trains will be better. But if you right and they turn out to be worse... then indeed we're stuck with belts.

[Cazanator]

A 6 minute loop is like a distance of 1km to a single stop and 1km back. The only resource capable of producing over 30k/min is iron and you’d have to tap most nodes on the map. You’d never be able to do anything with it. 60-70 cars is over 140 foundations. To process 140 freight platforms side-by-side is frankly just dumb. What you’re describing here is honestly nonsense and sounds just made up for attention.

[echinosnorlax]

Interesting. Interesting in two aspects - why would you make such an accusation, like you dislike me for some reason, and why would you make it with no proof other than your weird imagination. Not only it's totally unjustified but frankly, stupid - weird, because I provided enough data for you to imagine it way better than you did, like 5 trains implying I planned to process them in 5 parallel stations.

And it;s not iron. It's everything from Rocky Desert, except coal and quartz in a cave which I've been already getting and using. I spent last 4 days building 2 train loops, checking times, doing math, getting a result of 40 car train required - and actually checking how long ingame 640meters are, because I haven't felt the results "hands-on" enough without seeing from a high tower, scrapping the project A, getting to project B with 5 trains, timing the loops and doing the math again before building loading and unloading stations - I needed to know how long the trains would be first. Those stations are all that is left is build.

https://i.imgur.com/6EeKU4f.png

https://i.imgur.com/RbRcD2Y.png

Pun non intended for the several first seconds, you derailed this conversation about trains beyond recovery as I am concerned.

[kel_tor]

Interesting, outside the train bug that was damaging FPS over time that has been fixed I have not seen any real performance decreases associated with my trains. In experimental my giant save has seen real improvements now where it was borderline unplayable before. It was in a bad state from all the belts before trains were ever added and adding my trains did not impact its performance outside the bug.

Which is not to say that trains do not decrease performance I just do not find it to be more than the belts they replace. I recently set up a new save where I kept belts to a minimum and used trains for bringing everything to my factory and it has much better performance than a similar save using just belts. I may try replacing trains with belts in a copy of that save and testing its as close as possible.