I recently installed the hybrid cooler on the Titan and went for some overclocking tests.
Up to a certain point, performance (measured by Firestrike & Furmark) increased when base clock and boost clock were raised with Precision X. Power target was kept at 110%.
At about 80 Mhz GPU Clock Offset and 60 Mhz Memory Clock Offset, performance starts decreasing. The temperature never exceeds 45°.
I am not an experienced overclocker, so I am not sure what this means. I was of the opinion that the benchmark rather crashes when the card reaches its limits.
Those offests are rather low compared to others I read about in overclocking tests.
Any ideas? Thanks in advance!
 
 
 

I don't believe Boost will drop like that until you hit around 70c or 80c (even if you adjust the temperature slider for boost.) It may be that you're hitting the power wall, but you'll generally see that by a reduction in your core speed. Also, your memory could be clocked too high and is becoming unstable. That can also cause your scores to decrease.

If I were you, I'd max out that power target and temperature target (assuming you're on water with 45c temps under load lol) and pop out the graphs in Precision X. Run the benchmark and check your graphs immediately after to see if you're seeing your clock bouncing around a lot. The best way to overclock with boost 2.0 is to bump up your clock rates and watch the precision graphs. If you see that you're hitting the power limit, that's why your clock would begin to reduce and you'd possibly see lower scores. Temperature target will result in the same sort of behavior. You basically want to overclock and ensure that your card is staying at full load without the clock speeds bouncing around much.

What voltage are you running? I assume you've got the voltage tab maxed out as well (probably around 1.25v I think?) If you were overclocking and didn't increase the voltage slider as well as max temp/power target, then you're probably hitting those limits quickly while trying to push your clocks higher.
 
Also, what is your effective clock? Offsets will vary from card to card because they'll all boost differently on their own. My +80 on the core may give me 1500mhz while +80 on yours could be 1550 or 1450 depending on the luck of the draw (numbers are just an example.)

Boost bins exist at all sorts of different temperatures. It is progressive through a wide range of designed operating temperatures. The throttle at 75-80 is thermal throttle where clock starts dropping below base clock. Many boost bin reductions at lower temperatures exist.
I agree that it is most likely a boost bin issue caused by either jumping down to a higher temperature bin or because of power limit dropping it down a bin. I agree that we need information/graphs of real-time values for frequency, temperature, and power in order to decide what needs to be done to keep it at the higher performance level.

Not read the replies, but guessing it's throttling... Maybe your temp reading are not accurate? Happened to me with my SLI windforce cards that I had to send back. Didn't realise I needed reference blowers for SLI.