Hello HayzBaby,
 
You can try a few benchmarks like 3d Mark or EVGA OC Scanner X, which should put the system under heavy load. If you are having issues with the latest NVIDIA drivers, I would recommend rolling back to driver 314.22, with a clean installation. You can perform a clean installation by checking Custom instead of Express, and checking the "Perform Clean Installation" check box. 
 
If you have any further issues or questions, feel free to contact us 24/7 at 1-888-881-3842 or by email at support@evga.com.
 

Downclock the core & memory by 105 and see if your problems continue.

HayzBaby
this would be the gpu clock offset and memory offset slide bars correct?

Yep.

No problem. Report back when you can. 

Yes, hitting the VRAM limit could cause all sorts of problems. 

I want to upgrade sooo bad, but im waiting on the x99 chipset to refresh to more client side mobos, one sided ram slots vs the dual side. or whatever purpose that serves these days.
 
But so far my card hasn't had problems, still need to test it hard though, ive had mild play days since i put the thread up

I have the 480 FTW hydro copper that I won in the EVGA scavenger hunt in 2010 and have some of the same problems the past couple years. I have the display driver stop responding and recovered, which it really does not recover as the game either drops to desktop and not able to bring it back up or just crashes when that occurs. I found my problems go away if I take some of the FTW overclock off (like about 50Mhz off the core bringing it to about stock clocks) and also raise the cards voltage up one notch.
I've not played Arma 3 so unfortunately can not compare with you on that.
 
I'm pretty much in the boat you are except I have a in effect lifetime warranty also with a premium RMA option. Thing is the card is starting to show it's age a bit with it being able to only run Witcher 3 on mostly low settings. Pretty much the only game it's not been able to handle at least high settings on. My predicament is do I RMA the card, not even sure what I'd get back , fairly certain it would not be a 480 FTW HC though or do I just show my gratitude to EVGA for nearly 5 years of free use from the great card and buy a new GTX 970 SSC 4GB.
 
One thing you can try is to take your core clock down a bit more, 50 or 100Mhz and see if that helps. If not then as you speculate it may well be you hitting the Vram ceiling that is causing your problems but you said it has been doing this for years so what other games have you played that may be maxing the Vram. My case I've only seen Skyrim and Total War:Rome 2 max my Vram and I've not seen much in the way of ill effects other then a bit of intermittent stuttering.

HayzBaby
I've taken it down 105 as stated above, and it helped but end result is still the same, games minimize to black screen, and won't come back up. forcing me to task manager and end task etc. that runaround game is getting old rofl

I meant another 50 or 100 more or even more just to see if hitting the Vram ceiling is for sure the culprit (I have my doubts as you said it occurs with multiple game) or if maybe your cards components are just decaying from age and is starting to fail.
That black screen and the game not coming back up is that driver failing and supposedly recovering that I described just in your case you are not getting the pop up informing you of that for some reason. I'd go out on a very sturdy limb and say your event viewer would be loaded with that among other "nvlddmkm" errors if you look at it after you get the issues.
 
Also not sure how you install graphics drivers but it is usually a good idea to do the custom install and choose what parts of the driver package you want installed. I personally only install the driver itself and Physx. I do not want or need the, to me, useless Geforce experience or any of that 3D garbage or even the HD audio. Don't need any of it personally and if it was installed it would be just more that could go wrong. ;)

this would be the gpu clock offset and memory offset slide bars correct?