First and foremost, my primary question is this: Aside from heat production and potential of frying the chip, what (if any) are the other unwanted side effects of high overvolting for daily use? If the card is running with a high voltage and staying under 70C, is there really any potential harm being done to the GPU?
My Vapor-X 7970 GHz Edition came from the factory at 1.256v as stock voltage. Now from what I understand, that's already a pretty considerable over-volt compared to the standard, base-line HD7970. Does the Vapor-X GHz have more over-volt headroom than a standard, basic 7970? Or do they both share about the same voltage ceiling before they fry? Regardless, is 1.4 volts a safe limit, or is that being too liberal? I've heard people say they wouldn't dare push past 1.25v with a basic 7970, but considering mine came from the factory with 1.256v, that seems more like paranoia. I honestly am not even slightly worried about heat production from over-volting because the Vapor X cooling tech is very effective and this card currently tops out at 65C under stress testing with 1200Mhz and 1.24v (actual voltage, not target).
The other thing: My card has a very annoying Vdroop, and I believe most 7970s do. Whatever I set my voltage to in TriXX, my actual voltage always tops about 0.02v lower than the value I entered, and averages about 0.065v lower than the target voltage. At the "stock" 1.256 volts, a 1200Mhz core clock is about 95% stable. But every once in a while, vdroop will drag my voltage down so low that 1200Mhz is no longer sustainable, resulting in a few artifacts for a brief moment or even a crash/freeze. As long as I keep above 1.18v, 1200Mhz works. If I enter 1.3v in TriXX, I am 100% stable at 1200Mhz and actual voltage tops out at 1.28v.
The behavior of the voltage is a bit strange. When playing a game, if I enter 1.3v in TriXX, actual voltage hangs around 1.23v, but then for some reason spikes up to 1.28v for a brief moment right as I am closing the game. I'd like to increase my core clock even further, but I will obviously need a little more voltage. The vdroop is a problem because if I needed a constant 1.35v minimum to hit 1250-1300Mhz, those random spikes above 1.4v could fry the card. From browsing around I've found 2 ways to sort-of fix this.
1. Force constant voltage in MSI Afterburner. Although I prefer TriXX over AB (because I have a Sapphire card), I'd be willing to use AB just for constant voltage. Problem is, voltage control and monitoring is locked out in AB for whatever reason. I've done the "unofficial overclocking" steps but voltage control is still disabled. Clicking "Force constant voltage" does nothing either but I'm pretty sure that will not function if I am not able to control the voltage anyway. Does anyone know how I can unlock voltage control in MSI AB specifically for the Vapor X 7970 GHz? I've read this card is extremely difficult to adjust voltage with anything outside of Trixx 4.4 beta.
2. Flash a different BIOS. Correct me if I'm wrong, but I'm fairly confident GPU vdroop is a GPU bios setting. It works the same way as setting LLC (vdroop) for your CPU on your motherboard's bios. Reading around I found one particular ASUS test bios that supposedly has much lower vdroop. If there are any other GPU BIOSes for the 7970 that are known to have minimal vdroop, PLEASE point me to them. The reason I haven't tried the ASUS bios yet is because I wanted to make sure about the side-effects of running a non-Sapphire bios on a Sapphire card. I have the dual-bios switch in case I mess up, but is it a bad idea to run a BIOS from a different OEM, or is it pretty safe?