I apologize for the detailed post that is about to happen. ALSO, I believe that everyone needs to do their benchmarks in Haven, It is extremely stressful, and will really show you what is 100% stable with your card.
My GTX 670. I feel like she is a keeper. All of my stress benchmarks are on the Unigine Haven benchmark fully maxed at 1080p.
Clock: +0Mhz Boost: 1163MHz Memory: +0Mhz Peak Power: 73% Bottom Power: 69% Max Temp: 60*C Power Target: +100% Voltage: 988mV Score: 1238 Ave. FPS: 49.1
Power Target and Voltage Maxed:
Clock: +0Mhz Boost: 1163MHz Memory: +0Mhz Peak Power: 71% Bottom Power: 69% Max Temp: 58*C Power Target: + 112% Voltage 1.175v Score: 1224 Ave. FPS: 48.6
I thought this was weird, but in the first test, my second screen was black, whereas the second test allowed my to see that other monitor. I can account for the temperature by opening the windows, lol.
Starting Overclock (+50Mhz):
Clock: +50Mhz Boost: 1215Mhz Memory: +0Mhz Peak Power: 75% Bottom Power: 69% Max Temp: 58*C Power Target: +112% Voltage 1.175v Score 1268 Ave. FPS 50.3
Now, because the GPU managed to score higher with the power target at +100% as opposed to +112%, I ran my +50Mhz stress test one more time, but this time setting the Power Target back to +100%
Results were nearly the same. I lost about half a degree in temps, (57-58*C) and the power line actually steadied. The score was 1266, a mere two points lower, while Average FPS was the same at 50.3 FPS. Interesting.
Continued Overclock (+100Mhz):
Clock: +100Mhz Boost: 1263Mhz Memory +0Mhz Peak Power: 76% Bottom Power: 69% Max Temp: 58*C Power Target: +112% Voltage 1.175v Score: 1293 Ave. FPS 51.3
Continued Overclock (+110Mhz):
Clock: +110Mhz Boost: 1273Mhz Memory +0Mhz Peak Power: 78% Bottom Power: 71% Max Temp: 58*C Power Target: +112% Voltage 1.175v Score: 1297 Ave. FPS 51.5
Offically hunting for the magical 1300Mhz
Continued Overclock (+120Mhz):
Clock: +120Mhz Boost: 1283Mhz Memory: +0Mhz Peak Power: 78% Bottom Power: 71% Max Temp: 59*C Power Target: +112% Voltage 1.175v Score: 1306 Ave. FPS 51.9
There were some screen flashes that made my heart race, thinking there was going to be a crash... but it stuck it out through the Benchmark.
Continued Overclock (+130Mhz):
Haven crashed about 25 seconds from finishing. I never did make it to my magical 1300 Mhz. However, this is with a locked BIOS... I believe that I will unlock my BIOS had push for the 1.3Ghz
TL;DR: 1283Mhz Boost, Haven't played with Memory Yet, Power Peaks at 78%, Maximum Temp is 59*C at 63% fan speed. I have Power Target at +112% and voltage at 1.175v. In MAXED Haven Benchmark, I score a 1306 at 1080p with an Average FPS of 51.9.