Sim update 5 changed so much and with that in mind this is my idea of the perfect BASIC new build and set up not including choice of CPU and GPU (and associated cooling) and also not newer poorly supported PCI-e 5.0 technologies yet to be widely avilable.
Mainboard : Avoid no name brands, should be at least B450 but B550 recommended and should already be proven stable for for the level of CPU and GPU you intend to use with it including any overclocks, things like adequate chipset and NVme cooling can make a real difference. NVme support is essential now that DX12 is here and ideally PCI-e 4.0 (B550). Additionally 4 or more memory slots are recommended.
PSU : Ideally at least 25% more powerful than your build’s TDP, a higher wattage rating does not consume more electricity.
DDR4 RAM : Again avoid cheap brands and it’s generally best to visit your board makers site and pick from their support list however often there’s more recent modules with faster timings (CL not base clock) not yet tested but that will probably be fine (be careful with the packaging and you can usually get a refund). Base speed should always be within the MB’s specific range and fastest available is not always the most stable. PC-3200 or PC-3600 recommended and currently 16GB is fine for all but VR but expect to need more once multiple monitors are supported.
Storage: M.2 NVme X2 (although it’s likely only one will be PCI-e 4.0) Size depends on your needs but it is best to have both system and sim on the fastest which can be as much as 8X quicker than normal SSD speeds.
Case : Just make sure there’s room for fans, airflow and of course your CPU cooler.
System : UEFI bios meaning GPT partitioning (essential for Windows 11). And all drives used for Windows, MSFS and all addons including peripherals etc. must use the NTFS file format and although it’s early doors I can confirm that MSFS runs very smoothly on Windows 11.
MSFS : As mentioned, best and easiest is all on your system drive which IMO should be the fastest and that includes any scenery and scenery caches. However that’s not so important for aircraft or most (airports aside) 3rd party mods which once loaded into ram generally stay there. I am hoping in future MS/Asobo will make it possible to split these.
Internet : your choice entirely, I suspect MSFS streaming servers don’t output much more than 50Mbps anyway but faster connections should mean quicker content downloads and updates. 50Mbps is recommended by MS and it seems to work well in sim. Once again, the quality of your connection has little to do with the speed that your ISP gives you. 4k at high LODs probably needs more, 150Mbps max).
I don’t expect everyone to agree and I certainly don’t expect you to throw away your old components but as the title says this is a from scratch solution. I hope people can benefit.
Edit to amend that Rolling Cache actually works best on a separate drive or in ram.