which modules should I use and in what situation.

[Ultra]

My factory is getting very big and I have a big production of level 2 modules. Im wondering which module to use and when.
Currently I have speedmodules in all my electric furnaces and some other things. Im using productivity modules for expensive things like green and red circuits.
I find that if you have much room then productivity modules is by far the best one since you can just add more production machines to get the same throughput.
You can either build a small inefficient factory with speed modules or a big efficient factory using productivity modules. So unless I have missed something then speedmodules are not very usefull since space is usually not an issue if you plan well.
Efficiency Modules are by far the least usefull module in the game. Why should I care about energy consumption when I can just have robots build huge fields of solarpanels. I think that efficiency modules are good if you are using steam but otherwise it is not usefull.

Im I doing something wrong or is there something I have missed. Where do you use your modules.

[NimrodAbsolution⁧⁧98]

For high end items use productivity modules to save x% of all the resources it requires
On something like mining drills either efficiency or speed
For jumpjacks under 1% use speed modules
For assemblers of basic resources and smelters use speed

I pretty much use speed modules in everything I can in my worlds but I play in peaceful mode

[Warlord]

I tend to cram efficiency into my miners and electric furnaces. Those will greatly reduce your power and pollution (sure, solar panel fields are cheap, but it's also nice to not have to maintain a defense or to add to biter evolution as fast). Speed modules I place in assemblers, particularly assemblers that take more than several seconds to make something (engines, CPUs, red circuits, robots, etc).

I hardly ever use productivity, as I like having low pollution and power, both of which productivity modules add exponentially. Not only does the power consumption go up (causing it to make more pollution) but it also multiplies the now-increased pollution by another amount. And unless you are short on a particular material, productivity modules are worthless compared to speed, as the production bonus does not compensate for the speed loss it gives to the product. You'd have to compensate for it with speed, at which point why not just use speed modules entirely for faster item production?

In all, it's conditional. I suppose productivity in some low level mass products (copper wires, gears) can come in handy. Speed in those machines eventually can lock up from making too much at once, or being unable to provide the raw materials to it fast enough (gears).

[profitX10]

I use a lot of mods, and in almost every one of them the modules become more important. In the base game I almost always use just efficiency modules, except in rare instances I will use productivity ones and then efficiency in a beacon next to the group to keep down the insane energy usage.

[hagfish]

My factory has been largely devoted to making Productivity III modules for the last couple of weeks. My reasoning: I put 1 copper ore in a smelter, I get 1.2x back. I turn the 1.2 plates into coils and get 1.7x back. Those go into a green circuit assembler and I'm up to 2.3x. Etc etc - my point is it multiplies each time you build a consumable 'intermediary' product. By the time you launch a rocket, you only need about 1/3 of the raw resources. Ore patches go much further, and you need fewer trains, miners etc. Bringing new ore reserves online is not my favourite element of the game.
To get the speed back up again (Productivity kills speed), I use beacons. This makes my investment in modules go further. Speed III is also great for depleted oil wells.
Rocket Control Units are tricky because blue circuits are considered an 'intermediary' part (you can use productivity), but Speed 1 modules are not, so it's harder to match your outputs.

[ddddd]

........

[Acarin]

There are various long discussions on this topic on the Factorio forums (forums.factorio.com), and the short version is that it depends on your style of play and requirements.

Personally, I use PMs for oil-based production (refineries, cracking plants, sulfur, acid and plastic) with SMs in beacons around them, and EMs in my furnaces. Productivity modules are a godsend for your rocket silo as well!.

If you have the production capacity, EMs are also great in miners to cut down on the pollution which all-too-frequently triggers biter attacks.

[AlexMBrennan]

My last factory is using productivity modules with speed beacons pretty much everywhere which is working surprisingly well (whether it is "ideal" is another matter). I don't use effiency modules because pollution from miners doesn't really matter when you have 500 yellow assemblers with 4xPM3s

[Ultra]

I dont have a mega base yet while I can make level 3 modules right now I dont think it would be worth the investment at this point. I produce about 7k iron per minute about 4 blue belts. my shortage at the moment is green circuits. I think I will start level 3 module production as soon as I have expanded green circuit production. But at the moment I have productivity modules for red and green circuits and speed for evrything else

[AlexMBrennan]

I dont think it would be worth the investment at this point

I would argue that it's always worth it in the long run (i.e. if you are not planning on speed runs or campaign levels) - high power consumption increases the number of solar panels and accumulators your need (a one time expense), whilst slow crafting speed forces you to build more assemblers in parallel (a one time expense) but productivity modules will save you resources for all eternity.

[Acarin]

If you are producing 7k iron/minute, you are well on your way :-) My middle level base (currently busy producing infrastructure towards a Megabase) is running 10.5k total plates per minute, which gives me 3.4k green circuits a minute (and a tier 3 module every 16s or so). It sounds as though you are at the point where module production on an acceptable scale is feasible :-)

[Ultra]

Originally posted by AlexMBrennan:

I dont think it would be worth the investment at this point

I would argue that it's always worth it in the long run (i.e. if you are not planning on speed runs or campaign levels) - high power consumption increases the number of solar panels and accumulators your need (a one time expense), whilst slow crafting speed forces you to build more assemblers in parallel (a one time expense) but productivity modules will save you resources for all eternity.

That may be true however If I tried to make level 3 modules it would make them very slowly and i would just build my factory faster than I make modules. So the production wouldnt keep up so alot there wouldnt be enough modules for evrything.

Originally posted by Acarin:

If you are producing 7k iron/minute, you are well on your way :-) My middle level base (currently busy producing infrastructure towards a Megabase) is running 10.5k total plates per minute, which gives me 3.4k green circuits a minute (and a tier 3 module every 16s or so). It sounds as though you are at the point where module production on an acceptable scale is feasible :-)

yeah I think so too however i may be producing enough copper and iron plates Im certainly lacking in green circuits which is the next thing I will expand.

but I dont know if I should just skip efficiency modules and just produce speed and production since I dont find efficiency usefull. I can allways kill biters and expand my solar farm. energy consumption is not really an issue.

[Acarin]

You don't have to do everything this game - there is always next game. It's a learning curve :-)