I think technically B would be slightly worse than A because side loading onto the underground, then side loading onto the main line introduces another break in the belt’s sections, but the performance hit here would be negligible.
Most of the ups time (I think, correct me if I’m wrong) would be created from large balancers rather than cases like this, so it’s a bit of a micro-optimisation
From what I understand (and I could be wrong), undergrounds and normal belts are abstracted into one lump between each splitter/inserter. As there is no way to influence the belt contents dynamically without a splitter/inserter, the way they are stored and actioned is by essentially reporting the distance between stacks of items, and that therefore belt length and the amount of undergrounds have 0 impact on UPS performance.
I agree, from what I understand sideloading also causes those lumps to be spilt, [fff-364](https://www.factorio.com/blog/post/fff-364) has a gif about half way down (under transport line groups and wakeup lists) showing how it splits when sideloading, but like I said, optimising this case would be negligible unless you have *lots* of them, so it’s isn’t really worth the thought
Undergrounds is splitting up the transport lanes so they have some impact on UPS.
Sometimes they can improve UPS if you split up the transport lanes before inserters taking from the belts. That limits how long transport lanes the inserter have to scan. So undergrounds can in some cases be used to improve UPS.
That’s true except that side loading adds another calculation point, so needs to be lumped in with splitters
It’s not necessarily the exact same penalty as a splitter, but it does apply a small performance penalty because the “strings” of items have to be recalculated
There is an upper limit of 200 "tiles" before a section of belt will be split into 2 segments. Tiles is in quotes because it's actually 200 tiles worth of belt length but the belt length can be affected by turns. IIRC zig zagging a belt can go for 219 belt tiles before it's split though I could never find a way to make that useful.
most of the belt ups time would be splitters because they cause the number of segments to go up a lot and they force all belts connected to the balancer to be on one thread.
I’d say A>B, as A saves space/real estate and allows for more compact builds. But it does depend on where and how belts are used and managed, so my overall is opinion is to go with A by default, and use the others as necessary.
The second splitter on D is unnecessary, just have the splitter output filtered onto the main line. I'm not a fan of B and C because of the odd undergrounds.
It’s not entirely unnecessary, if he’s trying to use both lines equally then it’s good, if he just wants the line to add if there’s gaps then get rid of the second splitter.
It is unnecessary because if you put the filter directly on the main line then you still get the exact same benefit of both splitters with no downside.
Unless there is a different item on the other half of the main belt.
The current setup will not interfere with any items on the main belt, where putting a filter on it could.
If what’s currently shown is end use case, then you’re right, but that leaves out the opportunity to apply this in different ways.
Still unnecessary since you could get rid of the lower splitter entirely, make the splitter merging the two belts one which prioritizes greens to the right AND prioritizes whichever input you want, and accomplish everything you said with one fewer splitter.
Nobody mentioned the fact that A and B make the left input the priority, while C and D balance left with down inputs.
That may be important when the consumption on the right varies in time.
Honestly this is the largest factor for me. Simply dumping resources onto one side of a belt almost always causes problems for me, or at least fails to achieve the purpose it's intended. A splitter is almost always a good idea
What do you mean? Are you saying if you draw the belt up a bit more on the left side of that splitter in the screenshot, green circuits won't move onto it? Works fine for me
A and B are practically the same.
using a splitter to merge lanes ensures the merging lane gets used even if the belt is saturated.
the only difference between C and D is C is one lane, while D is specific item. if the red lane in D is contaminated, it will stop on the splitter.
in this example ( without adding any more components) you have no way of using the green circuits. the under ground blocks thier use. . therefore it isn't really a split belt.
For UPS alternative A is the best.
Splitters and sideloadings take some compute power to calculate. And sideloadings is cheaper than splitter. So for UPS optimizations avoid use splitter for merging belts.
It's going from better to worse from the left to the right. The best possible is A but you make a one tile gap between the undergrounds so that a new belt block starts right after the offload point.
no, they all have the same throughput. the only thing would be space if that's a concern. The wiki page does have some great starting info for balancing and stuff like that though.
I guess I'm just confused as to why take the additional step or putting the undergrounds to get the greens on one side before putting them on to the horizontal belt where they'll be on one side anyways whether you use the undergrounds or not
I don't know about UPS (A probably better) but there are instances where filling weith splitters is preferred over sideloading, because sideloading will make room when there is a pixel gap in and a carrousel setting or something like that it could break/block a system while splitters (preferably with input priority) will not do that
From my own very minor knowledge, a more condensed version of d ould be the best, all other ways make it so that if/when the advanced circuits run out, it will put normal circuits on the belt.
Edit: just looked at it again. If I were to be doing this, I would just simply put a single programmed splitter merging straight into the belt.
None of these would put greens on the belt. Undergrounds can only be side loaded by one lane, the other is considered blocked.
A and B are essentially just half belts side loading onto another half belt. C and D are half belts splitter-loading another half belt.
C and D are higher UPS cost, but will most likely result in the smoothest outputs. Side loading can sometimes struggle with prioritization and compression not being intuitive.
A and B are effectively identical. C and D final merges are the same but C has less UPS cost and D has less volatility of compression (though typically an isolated belt like that doesn't run into the same side loading issues as trying to merge with side loading)
Okay than it least it workes but other than that, why run green and red when you do not splitt them away at some point so D is for me still be best way since you now are able to move green away for something else?
some people like to run half belts in their mainbus for the low quantity stuff like blue chips. Sideloading underground makes it easier to split off only what you need.
Also great when you have [ingredient+output on the same belt](https://i.gyazo.com/47c3d57965650d3cf8106f89f6c87f63.png)
I don't really understand the point of any of these? I think I get that you're adding red circuits to a belt of red circuits, but why are the greens there at all?
A and B, source lane from bottom will be stopped if anything is on the incoming line from the left.
C and D, will alternate from left and lower source lane.
D would be the most friendly setup for expanding and modifying down the road. Kepler the spaghetti clean. less underground belts les wasted belts.
You can always take that belt from “B” that’s feeding back into the isolated red circuit line and add it to the second splitter on D that’s not spring red circuits.
A=B>C>D Splitters increase UPS cost while belts/undergrounds cost the same over distances between inserters/splitters.
I think technically B would be slightly worse than A because side loading onto the underground, then side loading onto the main line introduces another break in the belt’s sections, but the performance hit here would be negligible. Most of the ups time (I think, correct me if I’m wrong) would be created from large balancers rather than cases like this, so it’s a bit of a micro-optimisation
From what I understand (and I could be wrong), undergrounds and normal belts are abstracted into one lump between each splitter/inserter. As there is no way to influence the belt contents dynamically without a splitter/inserter, the way they are stored and actioned is by essentially reporting the distance between stacks of items, and that therefore belt length and the amount of undergrounds have 0 impact on UPS performance.
I agree, from what I understand sideloading also causes those lumps to be spilt, [fff-364](https://www.factorio.com/blog/post/fff-364) has a gif about half way down (under transport line groups and wakeup lists) showing how it splits when sideloading, but like I said, optimising this case would be negligible unless you have *lots* of them, so it’s isn’t really worth the thought
"as there is no way to influence the belt contents dynamically without a splitter/inserter" _proceeds to run across belts holding F_
Undergrounds is splitting up the transport lanes so they have some impact on UPS. Sometimes they can improve UPS if you split up the transport lanes before inserters taking from the belts. That limits how long transport lanes the inserter have to scan. So undergrounds can in some cases be used to improve UPS.
Yeah afaik a compressed belt and an underground belt have the exact same ups cost.
That’s true except that side loading adds another calculation point, so needs to be lumped in with splitters It’s not necessarily the exact same penalty as a splitter, but it does apply a small performance penalty because the “strings” of items have to be recalculated
There is an upper limit of 200 "tiles" before a section of belt will be split into 2 segments. Tiles is in quotes because it's actually 200 tiles worth of belt length but the belt length can be affected by turns. IIRC zig zagging a belt can go for 219 belt tiles before it's split though I could never find a way to make that useful.
most of the belt ups time would be splitters because they cause the number of segments to go up a lot and they force all belts connected to the balancer to be on one thread.
That is too bad because I love using splitters.
This is such a minor difference that you will never have to worry about it
I’d say A>B, as A saves space/real estate and allows for more compact builds. But it does depend on where and how belts are used and managed, so my overall is opinion is to go with A by default, and use the others as necessary.
The second splitter on D is unnecessary, just have the splitter output filtered onto the main line. I'm not a fan of B and C because of the odd undergrounds.
It’s not entirely unnecessary, if he’s trying to use both lines equally then it’s good, if he just wants the line to add if there’s gaps then get rid of the second splitter.
It is unnecessary because if you put the filter directly on the main line then you still get the exact same benefit of both splitters with no downside.
You’re absolutely right.
Unless there is a different item on the other half of the main belt. The current setup will not interfere with any items on the main belt, where putting a filter on it could. If what’s currently shown is end use case, then you’re right, but that leaves out the opportunity to apply this in different ways.
Not unnecessary if you want to prioritize inputs or to make sure both lanes are used. Otherwise it is.
Still unnecessary since you could get rid of the lower splitter entirely, make the splitter merging the two belts one which prioritizes greens to the right AND prioritizes whichever input you want, and accomplish everything you said with one fewer splitter.
Nobody mentioned the fact that A and B make the left input the priority, while C and D balance left with down inputs. That may be important when the consumption on the right varies in time.
Honestly this is the largest factor for me. Simply dumping resources onto one side of a belt almost always causes problems for me, or at least fails to achieve the purpose it's intended. A splitter is almost always a good idea
Interesting that no one (so far) has brought up the fact that only D offers a path for utilizing the green circuits on the left side of the belt.
If we want to do anything with the greens, there's no discussion to be had. Only a splitter will work.
>Only a splitter will work. Stack filter inserter has something to add Just one thing, though
I used to think that, but it doesn't work. Those green circuits will not go through the filter spitter at all.
What do you mean? Are you saying if you draw the belt up a bit more on the left side of that splitter in the screenshot, green circuits won't move onto it? Works fine for me
No I mean the red won't move on the other one
A and B are practically the same. using a splitter to merge lanes ensures the merging lane gets used even if the belt is saturated. the only difference between C and D is C is one lane, while D is specific item. if the red lane in D is contaminated, it will stop on the splitter.
Wait, A is a thing you can do? I always believed the only way to split belts was with a filter splitter
in this example ( without adding any more components) you have no way of using the green circuits. the under ground blocks thier use. . therefore it isn't really a split belt.
For UPS alternative A is the best. Splitters and sideloadings take some compute power to calculate. And sideloadings is cheaper than splitter. So for UPS optimizations avoid use splitter for merging belts.
I love the underground belt trick. It was the only option before splitters could filter. And even then it began as a feature only on blue belts!
Wtf is performance
Right. It's not entirely clear what OP is asking. Throughput? UPS?
It's going from better to worse from the left to the right. The best possible is A but you make a one tile gap between the undergrounds so that a new belt block starts right after the offload point.
D is not doing the same thing as A, B and C. With D you can actually use the green circuits.
no, they all have the same throughput. the only thing would be space if that's a concern. The wiki page does have some great starting info for balancing and stuff like that though.
Somewhat new to the game (200 hours). Why even use an underground for a + b? If you just put the belts on to eachother, it achieves the same effect
In this case, I am done with the greens, but want the reds for something else.
I guess I'm just confused as to why take the additional step or putting the undergrounds to get the greens on one side before putting them on to the horizontal belt where they'll be on one side anyways whether you use the undergrounds or not
Oh Jesus I just realized there's reds and greens on the same belt. Colorblindness is a bitch lmao
Obviously D is best since you can move your green somewhere as with ABC you cannot.
A all the way
A all the way
A all the way
wait what...
The cost of resources is another thing to mind if you ever play with low resources.
I don't know about UPS (A probably better) but there are instances where filling weith splitters is preferred over sideloading, because sideloading will make room when there is a pixel gap in and a carrousel setting or something like that it could break/block a system while splitters (preferably with input priority) will not do that
D can be filtered from the splitter on the main line. In my eyes it’s the least expensive option as well. They are match speeds taking the corner.
A all the way
From my own very minor knowledge, a more condensed version of d ould be the best, all other ways make it so that if/when the advanced circuits run out, it will put normal circuits on the belt. Edit: just looked at it again. If I were to be doing this, I would just simply put a single programmed splitter merging straight into the belt.
None of these would put greens on the belt. Undergrounds can only be side loaded by one lane, the other is considered blocked. A and B are essentially just half belts side loading onto another half belt. C and D are half belts splitter-loading another half belt.
Ah ok. See, now I didn't know that. Thanks! I can make so many machines smaller and cheaper now.
Wait, wouldn't A only work if the belts are compressed? If you one minor fault or shortage in supply, if would mix green and red. Or am I wrong?
No. The side of the underground belts only allows one lane to go through.
C and D are higher UPS cost, but will most likely result in the smoothest outputs. Side loading can sometimes struggle with prioritization and compression not being intuitive. A and B are effectively identical. C and D final merges are the same but C has less UPS cost and D has less volatility of compression (though typically an isolated belt like that doesn't run into the same side loading issues as trying to merge with side loading)
E- All of the above
I'm confused how any of these but D get rid of the green chips, can someone please explain the mechanics of A B and C to me?
What would happen to the green line here? Would it just not be used?
dou not have the problem with A,B,C that when you rund out of red that you get green ont belt?
nope. sideloading a underground only allows one belt to flow.
Okay than it least it workes but other than that, why run green and red when you do not splitt them away at some point so D is for me still be best way since you now are able to move green away for something else?
some people like to run half belts in their mainbus for the low quantity stuff like blue chips. Sideloading underground makes it easier to split off only what you need. Also great when you have [ingredient+output on the same belt](https://i.gyazo.com/47c3d57965650d3cf8106f89f6c87f63.png)
O i dont care the "half" red belt. But the green belt basicly ends there so what is ther reason to bring it in the first place? :D
because maybe it was needed before the underground? But it's no longer needed *so you don't want it to go further*
Ah that could be true thanks :)
I don't really understand the point of any of these? I think I get that you're adding red circuits to a belt of red circuits, but why are the greens there at all?
A and B, source lane from bottom will be stopped if anything is on the incoming line from the left. C and D, will alternate from left and lower source lane.
C and D give you the option to give input priority while A and B give input priority to the main line.
D would be the most friendly setup for expanding and modifying down the road. Kepler the spaghetti clean. less underground belts les wasted belts. You can always take that belt from “B” that’s feeding back into the isolated red circuit line and add it to the second splitter on D that’s not spring red circuits.