GPU Boost

NVIDIA GPU Boost technology automatically increases the GPU’s clock frequency in order to improve performance. GPU Boost works in the background, dynamically adjusting the GPU’s graphics clock speed based on certain conditions. This actually originally with the GeForce GTX 680, the first iteration of GPU Boost was designed to reach the highest possible clock speed while remaining within a predefined power target. GPU Boost is now at revision 3.0. The Titan X GPU will automatically boost to the highest clock frequency it can achieve as long as the GPU temperature remains at or below 80C. The GPU constantly monitors GPU temperature, adjusting the GPU’s clock and its voltage on-the-fly to maintain this temperature. With the Titan X we can change several variables (using MSI AfterBurner) board to boost to higher clocks for example, we can simply adjust the temperature target higher (for example from 80C, to 90C). The GPU will then boost to higher clock speeds until it reaches the new temperature target. The power target setting no longer sets the typical board power instead it sets the board’s max power. At the default power target setting of 100%, the max power setting is 250W. At the max slider setting of 106%, max board power is 265W and 120% would be 300 Watt. That typical board power will actually vary a little based on the ambient temperature. GPU Boost thus gain better performance from better cooled (water cooled) solutions. Water cooling will typically keep the GPU temperature well below the target which will result in an allowance of higher voltages and clocks. We just discussed the new temperature target function and how it operates; another new option provided in GPU Boost is overvoltage control. Because Titan’s boost clock and voltage level is dynamic, Nvidia now allows the GPU voltage to go higher, this helps to ensure higher clocks, or lower once you reach the certain limiting targets. This voltage range is in place to protect the silicon from long term damage. However, some of our most enthusiastic customers may want to push their GPUs to the limit by raising the maximum voltage further.

Starting an overclock

When you want to overclock typically you need to verify and stabilize your tested settings. First off let us remind you that we always recommend increment offsets of roughly 25 MHz on core and 50 MHz memory (from the default base clock frequency upwards). In the first stage you overclock your GPU, in the second the memory. Once you get artifacts or a lockup, back down 25 to 50 MHz and typically that is your stable result in it's highest threshold -- under the condition that the room temperature is the same (yes GPU heat and surrounding heat have an influence on your overclock).

Related to heat is your graphics card cooling system. If you are willing to allow more noise, increase the fan RPM on the GPU towards a higher setting that you find comfortable. Cooling helps with tweaking if you normnally reach your temperature target!, it's as simple as that. That backside of your graphics card however gets hot as well, give it some airflow too. So make sure your PC casing is well ventilated with decent airflow.







AfterBurner 4.3.0 offers voltage control (to be released - not available to public at the moment of writing) comes with GPU and memory tuning, overvolting, allowing control and adjustment parameters for overclocking.

AfterBurner 4.3.0 offers voltage control () comes with GPU and memory tuning, overvolting, allowing control and adjustment parameters for overclocking. Original This sample Overclocked Core Clock: 1417 MHz Core Clock: 1417 MHz Core Clock: 1667 MHz Boost Clock: 1531 MHz Boost Clock: 1531 MHz Max Boost Clock: 2050~2114MHz Memory Clock: 10000MHz Memory Clock: 10000 MHz Memory Clock: 11204 MHz

Now then, overclocking did get more complicated as increasing the GPU temp has an effect on voltage and thus power consumption which effects the maximum allowed board power and so on. So really it is a matter of trial and error and finding your preferred or maximum balance in terms of extra performance versus noise levels. For this article we use AfterBurner, this is a new Beta stage development build in which we opened up voltage offset control, the release is still pending and not available to the generic public just yet. Even without voltage control you'll reach the 1900~1950 MHz marker. The memory on our sample was insanely tweakable as we reached 11.205 MHz (effective data-rate).

Our GPU frequency will fluctuate depending on power draw / heat and other limiter. Feel free to try our settings yourself. We applied:

Power Target 120%

Priority is set max for both the Temperature and not Power Target

Temperature Target 90 Degrees C

CPU clock +250MHz

Memory clock +600MHz

Voltage +100%

Fan control RPM fixed at 80% (noisy).

The trade-off for today is cooling. The biggest limiter for Titan X is the temperature target of 80 Degrees C. Once it reaches that stage the card will down-clock. So please do set the temp target to a higher level, yet also increase the fan RPM. We set it at 80% and that is incredibly loud. But we are testing tweaking performance today, not noise levels. The cooling for Titan X can be considered very average, of you purchase a card we can highly recommend to look for a liquid cooling block. Once we set our temperature limiter and fan RPM, we increase the GPU frequency, voltage offset and increase the power limiter.

What about memory?

With the massive amount of memory bandwidth you have available normally I woudn't touch memory too much. Overclocking memory costs extra power and your power budget is limited towards 250 Watt + roughly the max on your power limiter, you want that power to be distributed and used for the GPU where there's more performance gain to be found. However we have 75 Watts over the PCIe bus and then 75+150 being fed through the power connectors, 300 Watts should be plenty for a stable tweak on the memory as well. Typically what we have seen with the 10 GHz GDDR5X is an increase of 10%, we have been able to lock in the effective data-rate at 1.1 GHz, and yes the card does like extra memory bandwidth.

Mind you that this is all done with the reference air based cooler, the dynamics could change with liquid cooling quite a bit. Let's first go check out what this overclock does to the boards power draw, noise and heat levels.