stop doing the 700 stock series. they're horrible. it needs to be TI after it.
let's take the 980 for an example. 4,5gb vram. pretty cool. i can do pretty much all game @highest with a decently stable 60fps.
the titan x has 12gb of vram. the titan x is the dream. the 980TI has 6gb vram, but other things in the 980TI (both hardware wise and overclocked wise) makes the 980TI the affordable titan x.
same goes for all other series. the 750 is shit. the 750TI is amazing.
yes, it's most likely a bit more expensive, but really, in the long run it'll be far more expensive with buying a 600 series one. they're pretty much outdated, and every other upcoming game release will have struggles with the 600 series, because of specs and drivers.
and i'm not sure if this applies to normal cards (doubt it), but my 660M recently started to fuck over in my laptop. reason? the fan in the laptop couldn't give enough chilly air, so the gpu overheated.
that's a laptop card, however. but, i don't know if it's rumours or not, but i've gotten to know that the 500-700 series do get overheated pretty easily if they don't come with more than one fan.
i know for a fact that my 980 strix got two fans and is running really cool pretty much all the time. never really seen the gpu fans go over 50%, even when i'm using 100% of the card. however, that's the asus strix one. the one's with one single fan will most likely run more, louder and warmer. same applies to earlier cards, and if you're planning to push today's games on lowspecs cards, 100% of the card will be used most definently, and it'll spend alot of power to making sure it doesn't get overheated, by simply doing a performance loss, to make sure the card doesn't run 100%.