Optimum hardware for 2.x?

[NineNine]

My current game is starting to get really slow on my current computer, so it's time to upgrade. The last time I put together a computer a few years ago, the advice was:
- get the CPU with the most amount of L2 cache available
- # of cores doesn't matter because Factorio uses only one CPU at a time.

Does this advice still hold for 2.x? Is L2 cache on the CPU still the most important hardware bottleneck? And what else matters after that... CPU speed? RAM speed? Does the graphics card/GPU matter?

[Loewchen]

The optimum currently is the 9850x3d with low latency memory. The single core thing was never actually true but any modern cpu for gaming will have enough cores anyway.
What you should stay away from are the AMD cpus with cores on multiple dies like the 9900x3d.

[pioruns]

My current game is starting to get really slow on my current computer, so it's time to upgrade. The last time I put together a computer a few years ago, the advice was:
- get the CPU with the most amount of L2 cache available
- # of cores doesn't matter because Factorio uses only one CPU at a time.

Does this advice still hold for 2.x? Is L2 cache on the CPU still the most important hardware bottleneck? And what else matters after that... CPU speed? RAM speed? Does the graphics card/GPU matter?

Yes, all of the above matter. What CPU, GPU and RAM do you have right now? What UPS/FPS are you getting on your most advanced save? Would be nice if you uploaded utilisation stats during gameplay, so we can give you most informed upgrade options.

[Eulenberg]

The optimum currently is the 9850x3d with low latency memory. The single core thing was never actually true but any modern cpu for gaming will have enough cores anyway.
What you should stay away from are the AMD cpus with cores on multiple dies like the 9900x3d.

that is not true at all the 9950 x3d is on par, if not better due to higher baseline speccs and 30% more L3 cache, dual die is not an issue these days and if setup properly can even help because you can force all "background" tasks to run on non x3d cores while factorio gets the x3d cache exclusively, to boost cache hit by a non-unsignificant amount, as a rule of thumb for windows users enable gamebar and powersaving balanced and install the latest chipset drivers.

If you want to super optimise use process lasso to force everything, but factoio off the main ccd0(x3d part of the processor), at the end of the day any x3d will carry you massively due to the immense amount of L3 cache, even a mid-range last-gen x3d will do well, if your save is too large then RAM speccs is what matters, speed(thats the advertised MHz or MT number) as well as Latency mattera most (advertised as CL ), in my case i run 64GB with 6200MT/s at CL26, quite on the higher end for AMD, while i picked up this ram kit for 350 Euro these RAM-Kits are currently not sold, because quality RAM goes directly to AI-Corps, if you are lucky you can buy these kits for 1500-2200 Euro if you can even find them.
You can try to overclock 5800MT/s CL32 to 6400 CL28 if you are lucky with the silicone lottery, in any case you need to spent quite a fortune ATM if you want a "optimal" factorio PC, due to the RAM being your bottleneck sooner or later, you can find Buildzoid videos on youtube for easy to follow guides on RAM OC.

However even if you have a x3d and omega RAM, you still leave about 20% on performance on the road, if you just run factorio on windows over steam. There are multible knops to further optimize: Unsing linux (recommend CachyOS), running factorio Standalone(can be redeemed over the website even when bought via Steam), using RAM largepages(continuos memory, not fragmented), using mimalloc(a more modern and performant memory allocator, google for LargePageInjector by KeinNiemand on Github) Abucnasty on YT made some good benchmarking on these topics.

If you need further help with these topics im happy to assist