Well, well, well.
This is a benchmark mission for any system, if I ever saw one.
80 x B-17 (in words: eighty)
28 x covering fighters
vs
16 attacking fighters
That is
124 aircraft in a tight ass furball, shooting from all barrels.
I have a brand new system with good card and processor. I can run this mission "playable" but not great, could maybe squeeze performance a bit if i tuned down my post processing, but not by much, as the sheer amount of planes makes the processor the bottle neck.
(and if you have a real slow HDD, you can go fetch a cup of coffee while the bombers spawn a couple minutes into the mission maybe...)
AMD Ryzen 5 5600X (3.70 GHz)
Radeon RX6700XT 12GB
That said, I manage to run 24 - 18 FPS when fighting in the actual bomber stream, depending on where I look and zoom.
Playable, but If I had made this mission, I'd have tuned down the amount of planes, particularly the big ones. That, and only that is the key here.
On approach, I have a solid 55+ FPS
If anyone wants to test their system to the max, this is a mission to do that
See, and this is why I asked the question you never answered: How many planes?
I'd have told you this in my second reply if I'd have known the number.
But then, now you know how to post attachments