whats your excuse for a 780 with 8GB of ram then?
What? They don't make 780s with 8GB of VRAM and if you mean system RAM most people having issues are those with 8GB of RAM (and I was one) because the game will take up a shitton of it and with 8GB of RAM (or less) it dips into your page file like I already said and Gameworks makes it even worse, especially smoke, not sure if debris causes issues too but I've had them turned off for a while now.
I just tested it again with smoke and debris on along with AA which I also disabled before because it was useless shit after not having played the game in like a month. I'm using Windows 10 now and the smoke effect doesn't even seem to work but the problems (I'm willing to wager the Gameworks stuff almost certainly played a part in the memory leak issue). With everything on the game reached over 6GB of system memory with a 9.1GB commit (that I watched continue to rise as I played for all of maybe 10 minutes) and actually still managed to hit my page file despite my 16GB of system memory. I had moved the page file to my HDD after the W10 upgrade because it wasn't really being used anyway but since it went into my PF for 1.7GB of extra space it became stutter city as it had before when I tested and posted about all over the performance topic, it going into the PF wasn't really an issue on my SSD. The system usage is on top of nearly reaching 4GB VRAM usage before it crashed, this is at 1080p at the default 30FPS by the way. Obviously lowering the settings, what few there are, helps but regardless the game uses a ridiculous amount of RAM even with everything low/off at 720p, IIRC it required over 5GB when I tested that along with around 2.6GB of VRAM.
This isn't an excuse the game is in an absolute shit state that a lot of people have to manage to pretty much brute force to get playing reasonable and if you're saying it plays fine for you on a 780 with 8GB of RAM and you're using a regular HDD then you're one of the lucky ones to not have issues with the PC version.