Originally Posted by seward
I was wondering, when folks talk about max clocks with this card (or any other nvidia Boost card, I guess), are they talking about set clocks, or Boost clocks?
I can get my 780 Ti up to 1150mhz (Afterburner setting), stable in BF4. Boost is 1294mhz. (Volts are set to max in AB; I've had Power Limit up to 105%, doesn't seem to help, may actually make OC less stable. Memory is @ 1800mhz.)
Can I go around saying I got my card to 1294mhz, or do I gotta refer to actual software setting (1150mhz)?
That depends on how meaningful you want what you are saying to be. The default clocks and boost clocks are pretty much purely marketing bull and have little meaning beyond what GPU-Z shows on the main tab.
Fire up GPU-Z, switch to the sensors tab and watch what is going on with the following readings:
GPU Core Clock
GPU Memory Clock
If you leave the GPU idle for a few seconds, you will find it drop through the floor. On my modified Titan engineering BIOS, I can see:
Default Clock: 902 MHz
Memory: 1602 MHz
Boost: 941 MHz
Switch over to the sensors tab, and it shows:
GPU Core Clock: 536.6 MHz
GPU Memory Clock: 162 MHz
Power Consumption: ~6% TDP
Create some serious GPU load, and the readings go up to:
CPU Core Clock: 1097 MHz
GPU Memory Clock: 1603 MHz
Power Consumption: 98-103% TDP
The GPU core clock shifts around a bit initially in 13 MHz increments, and after a while under load, this stabilizes at 1058 MHz and will stay there as long as the load is ongoing.
The boost limit on this BIOS is set to 1202 MHz (you can check this with a tool like Kepler BIOS Tweaker), but the boost table goes up to 1267 MHz (again, you can increase this using KBT, but if you aren't getting to the boost limit under full steady state load, there is no good reason to do so).
If you look at GPU-Z sensors you will see what you are limited on (Pwr, Thrm, VRel/VOp).
To overcome each of those:Pwr
If GPU-Z is showing Power Consumption at ~100% TDP, Increase Power Target in Precision-X/Afterburner. If it isn't (or it stays at 100% (+/- 2-3%) even though you dragged it up to 105%, your BIOS is limited on something other than the total power which is what the power target slider adjusts. Open it in KBT and look at the power table. For example, I found that I cannot get to 350W without boosting the slot power (3rd entry in the power table) to 100W, which is potentially dangerously out of spec (75W limit). If you are going to tweak the power tables, make sure you read up on it and know what you re doing first.Thrm
1) Boost your fan to the maximum (and disable the auto fan control). Depending on your BIOS, the max % fan speed limit and rpm will vary. For example, with standard Titan BIOSes the limit is either 85% @ 4200 rpm or 100% @ 4200 rpm. The % speed is largely irrelevant, the important figure is rpm that GPU-Z is showing. The only BIOS I have found that has a higher fan speed limit is the Titan engineering BIOS from hwbot - on that the 100% fan speed is 5200 rpm. This is the main reason why I am using it on my Titan (it also sets all power limits to levels that are just silly, so I bolted those down to values that aren't liable to catch fire). Anyway, the point is that the first thing to look at upping for Thrm limit is fan speed.
2) Increase the temperature target using Precision-X. You can normally increase this to 95C. This won't blow your card up immediately (unless it is seriously marginal to begin with), but some people deem it too high for 24/7 usage. My cards hover in the 90-95C range while scrypt mining with fan at 100% for weeks now with no ill effect. Your mileage may vary.
3) Increase the clock offset in 13MHz increments. I know this is unintuitive, but increasing
the clock offset achieve two things - it increases the clocks (obviously) and it reduces the voltage for any given clock speed. Clock speed and voltage are related via a table in the BIOS that makes sure that for each clock speed a suitable voltage is applied. The faster the clock speed, the more voltage is needed to keep things stable. By offsetting the clock speed positively you are creating an offset between the clock table and the voltage table.
The reason this works to help you get more clocks within the power and thermal limits is because the power/heat increase with the square of the voltage but only linearly with clock speed. Boosting the clock speed to 110% increases power to 110%. Increasing voltage to 110% increases power to 121%.VRel/VOp
You could boost the voltage in the BIOS, but you should explore the clock offset option first. As mentioned above, offsetting the clock vs. voltage will allow you to try higher clock speeds for any given voltage.
Once you have dialled all that in and stability tested it with as high a load as you can generate (OCCT, furmark, cudaminer --benchmark), look at what your steady state clock speed is once it stabilizes in GPU-Z. IMO, this is the figure that is the only meaningful one to be brandishing around as how far you got with tuning your card. But pretty much nobody does that - so for bragging rights you might as well just make up a number for all the meaning it'll have and go with the fishermens' takes that most others go with.