By lowest everything, I'm guessing the performance slider is down as far as it can go, and all of the post FX (except Quality Lighting) are unticked?

We can artificially limit framerate which will help a lot with keeping usage down, but that does come with some other drawbacks. Are you able to tell if the game feels laggy in the areas where this happens? (this will basically answer whether that is a solution or not.)

 

Unfortunately I think that's basically linked - you're within our supported requirements, but on the lower end (10 years behind is about the furthest back we support).

On that kind of machine, we target around 10-15fps as the expected experience. GPU models tend to be expontentially better between generations, so it is a challenge to support higher framerates the further back we go - a 10 year old video card is 50-100x weaker than a 1 year old one.

This has a direct impact on heat however - if you have less than 30fps, we'll be using the GPU pretty much 100% to try squeeze that 10-15fps out. If you have greater than 30-60fps, we'll ease off a bit, which gives the GPU time to cool down a little before the next frame is requested. We can artificially increase that 'cooldown time' by lowering the target framerate, however that does have the impact of making lag worse.

The efficiency of how quickly your GPU can radiate heat matters too - if you've got a old computer, you likely have a lot of dust buildup, a $2 can of compressed air gently blown through the GPU vents will make a world of difference to how efficient it cools off -- which will mean the fan can run a bit slower too (and will extend the life of your video card).

I can look into seeing what we can do at exposing some more options to let you run with less effects - that will definitely help if there are useful options left to expose however. We're expecting to do a update in the next two weeks or so, that will be the soonest I can get those out however.