On AMD you probobly undervolted your cards to get them to use less power. On Nvidia you change the TDP of the card. You can do it in software with the nvidia-smi tool, or modify the bios. (voids warranty)
yes I modded the bios myself, 0.8V, stable at 860Mhz, 1250 mem (sapphire 7950 dual X oc)
are you saying that i can run under linux, before loading ccminer, a nvidia-smi sentence that will change in real time the TDP of every card??? WOW!!! I thought that the only way was modifying the BIOS!, do you have any link / tuto or hint how to?, I will get right on it!.
I decide not to modify the BIOS because if I fuck something up, there is no backup, in AMD 7950 there is a dual bios switch, if you fuck up your card (which I did more than 100 times when researching this) just move the switch to position 2, power cycle, move switch to 1, reflash, power cycle and good to go!, but nvidia has no switch!.
GPU's in my country are EXTREMELY COSTLY, and there is no such a thing like warranty here, if you fuck it up, it's gone, one card to the bin basket.
You can recover basically any screwed up BIOS in DOS with nvflash, you just need to plug your monitor into another GPU (onboard).
You can even shut down your computer midway flashing a card and still be able to reflash it next boot.
bathrobehero what is your regular ambient temperature?, I am in a very hot area, that could explain why my cards where working at 75C and yours at 60 
I had 12CM spacing between them, and a 3000 rpm fan between every card to prevent that one card heat up the other one, still, in quark specially, it was impossible to lower the temperature below 70C, in lyra2v2 yes, usually where at 60 probably, don't remember exactly.
true WD Green dies fast! for offline storage they are ok, but not for much else, even if you modify the parking time (i usually do, to 30 or 60 seconds), I always use black or red drives which has better warranty and lasts longer too (one of the few companies that has true warranty in my country, WD, and is excellent!)
still mining kills a lot of hard drives, until i switched to usb flash, I killed about 10 or 11 wd black, reds, and seagate drives beyond repair, keep in mind that it is the mix of 24/7 operation, a LOT of power outages (here power is extremely unstable, we have short brownouts at least 10 per day) and at least 1 power outage a week, 1 of 4 may last days.
(reason why I spend a ridiculous amount of money in inverter generators, smart UPS, solar panels, power regulators, inverters, I even have a low voltage line across the apartment for the essentials (battery powered)) add to all that, high temperatures and high humidity and you get....HELL !! hehe
About the SSD, mining OS does not write a lot, just moving the logs and temps to ramdisk is enough, a crappy kingston V300 will last at least a couple of years easy.
of course someone mention that the 840 Pro still works, of course, it is one of the best SSD consumer drives in the market! I have one in my workstation and is fantastic and very fast!, but at almost twice the cost of the kingston, it worth it for your workstation but not for a miner IMHO.
I had an excellent experience booting of flash USB drive, almost all of my stability and disk problems went away since i boot off USB flash drive, so I will keep doing it hehe. (I know i am a stubborn sob )
I had 12CM spacing between them, and a 3000 rpm fan between every card to prevent that one card heat up the other one, still, in quark specially, it was impossible to lower the temperature below 70C, in lyra2v2 yes, usually where at 60 probably, don't remember exactly.
true WD Green dies fast! for offline storage they are ok, but not for much else, even if you modify the parking time (i usually do, to 30 or 60 seconds), I always use black or red drives which has better warranty and lasts longer too (one of the few companies that has true warranty in my country, WD, and is excellent!)
still mining kills a lot of hard drives, until i switched to usb flash, I killed about 10 or 11 wd black, reds, and seagate drives beyond repair, keep in mind that it is the mix of 24/7 operation, a LOT of power outages (here power is extremely unstable, we have short brownouts at least 10 per day) and at least 1 power outage a week, 1 of 4 may last days.
(reason why I spend a ridiculous amount of money in inverter generators, smart UPS, solar panels, power regulators, inverters, I even have a low voltage line across the apartment for the essentials (battery powered)) add to all that, high temperatures and high humidity and you get....HELL !! hehe
About the SSD, mining OS does not write a lot, just moving the logs and temps to ramdisk is enough, a crappy kingston V300 will last at least a couple of years easy.
of course someone mention that the 840 Pro still works, of course, it is one of the best SSD consumer drives in the market! I have one in my workstation and is fantastic and very fast!, but at almost twice the cost of the kingston, it worth it for your workstation but not for a miner IMHO.
I had an excellent experience booting of flash USB drive, almost all of my stability and disk problems went away since i boot off USB flash drive, so I will keep doing it
hehe. (I know i am a stubborn sob )Sorry, I meant to write 70°C, not 60 for the max temp for the 970 OC cards (I have 60°C temp limit on the 750 Ti's). The ambient temp now in the room where the rigs are is 21°C and the hottest 970 OC card is 62°C (80-85% fan). If I remove the temp target on the minis, they climb to 74-77°C.
I have no idea about the humidity.
Power here also isn't the best but it's nowhere near as bad as yours so I guess that's killing your harddrives. The two WD greens I have and used to mine burst for over a year (stopped about 6 months ago) have no isses so far and are at 800 load cycle (5 min parking time). I don't store anything important on them though.
Yes, the 840 Pro is great but mostly because it's fast but it still uses TLC NANDs and the crappy V300's which I have in all mining rigs have MLC NANDs which should be way more durable.
I always had terrible experience with USB drives though, maybe I just used really crappy ones.
Just to be slightly on topic: ccMiner SPMOD Release CUDA 6.5 vs CUDA 7.5 Performance Comparison