The product page for the Early Access on Steam lists a minimum of something like a GTX-970 graphics card with 4GB VRAM, and I was concerned, that it won't run on my machine as it only has a GTX-580 with 1.5GB VRAM, but it does run, even though the sliders are a bit more to the left :-). Just wanted to mention this if anyone else hesitates due to the minimum system requirements.

Thanks siggy, that IS good news! I thought I was getting away with it having a GTX750Ti with 2GB (which runs FSW with the sliders at default).

Like when engineers put a limit on how much a piece of machinery can take before it breaks, and typically err on the side of caution, it is usually the case with developers that they will put a slightly raised spec level as a minimum, principally to cover their asses concerning people potentially complaining about its performance. Thus I've found it runs well on one of my PCs which is very seriously below minimum recommended spec.

However, you should bear in mind that whilst FSW might be running okay now on a lower specced machine, many features are not in it yet, for example real weather downloading and creation, enhanced night lighting, nor are there any fancy add-ons shoehormed into it either, so these would add to the system load, although having said that, it also isn't fully optimised yet, so the chances are it will actually run a bit better in its present state after those tweaks are made part of it.

As with anything flight simmy, we need to remember that they put those option settings sliders in there for a reason and half the time when one sees someone complaining about FPS or stutters on forums such as Avsim, they could sort out their problems by just accepting they might have to take everything of full throttle in the options settings.