NVIDIA GeForce GTX 1080 Founders Edition Review

NVIDIA's next generation video card is here, the GeForce GTX 1080 Founders Edition video card based on the new Pascal architecture will be explored. We will compare it against the GeForce GTX 980 Ti and Radeon R9 Fury X in many games to find out what it is capable of.

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GPU Boost 3.0 Clock Speed Consistency

GPU Boost has been improved on GeForce GTX 1080 Founders Edition. It should potentially maintain a higher to maximum capable clock speed while gaming. Remember, on NVIDIA GPUs there is the base clock which is the clock speed you don't want in-game clock frequency to drop below. Then there is the boost clock which you can think of as extra performance or clock speed the GPU is capable of based on load, TDP, temperature and now voltage.

While NVIDIA has a quoted level of boost clock this clock speed is not guaranteed. The actual in-game clock speed will vary as you play games and could be under the quoted boost speed, or over it. What we want to find out is how well the Founders Edition maintains its boost clock considering it is "reference" cooling.

Temperature can hamper GPU boost clock speed. If the GPU gets too warm, it will throttle back the GPU boost clock below the quoted speed. Therefore, we need to find out what exactly the new GeForce GTX 1080 Founders Edition is doing while gaming.

In order to get a thorough evaluation of this we have to play a game for an extended amount of time and record clock speed over time with GPUz. We chose a 30 minute multiplayer playthrough in Battlefield 4 which has proven to be a good test for this, the game scales well and utilizes the GPU quite well. We took clock speed readings as well as temperature readings.

This will tell us what clock speed the GPU starts out with in a game and what clock speed it settles down to and the average clock speed while gaming. What we want to see is the clock speed be at least at the quoted GPU boost clock speed, and never drop below the base clock.

The base clock is set at 1607MHz and therefore we have put our red line at this frequency. We don't want to see in-game clock speed drop below this. We have put our green line at 1734MHz which is the quoted GPU Boost clock speed. We want to at least maintain this clock speed. Note that ambient temperature in the room was 75F.


Clock Speed

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What this graph shows us is that at the start of the game GPU Boost is running the clock speed as high as 1885MHz (1.885GHz), however that is extremely short lived. The clock speed quickly descends from there over the matter of one minute. In one minutes time it has dropped to around 1800MHz. However, that is not its final resting point. It takes about 5 minutes for the clock speed to settle to its consistent frequency for the remainder of gaming.

What this first shows us is that if you run a short benchmark to gauge performance on the GTX 1080 results may be quite high as the clock speed is quite high for the first 5 minutes. However, after 5 minutes of gaming it settles down to quite a lower position. This means it is extremely important to either test long sessions of gaming to gauge actual performance or let the video card "warm up" before evaluating performance so that you get real actual results and not inflated performance. It also shows the cooler can't maintain the highest clock speed either.

The clock speed seems to average out to around 1770MHz (1.77GHz) according to the table. If you look at the graph the frequency likes to hover between 1760MHz-1785MHz most of the time. The good news is that this is mostly all above the quoted GPU Boost clock of 1734MHz. It is at least 30MHz higher, and sometimes more. However, you will note that there are many times the clock speed does dip below 1734MHz. These are not prolonged spikes, but a couple did go all the way down to the base clock for a second. Thankfully none of them dropped below the base clock.

On the one hand the performance is mostly above the GPU Boost clock speed. On the other hand it starts out really high above 1800MHz but cannot maintain this due to factors, one of which is temperature. Perhaps better cooling will allow the frequency to maintain a higher than 1800MHz frequency. This could bode well for custom cooled partner boards.

Temperature

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This graph shows the temperature from a cold start of the video card so we can see how quickly it ramps up to maximum temperature. The video card takes about 5 minutes to reach its maximum temperature of 83c. This is the same exact time it takes for the clock speed to drop down to its consistent clock speed.

This shows a direct correlation between temperature and clock speed. At the same moment the GPU reaches its maximum temperature is the same moment the clock speed drops to 1785MHz. This shows that temperature is affecting clock speed on the Founders Edition.

It should be noted the fan reached a maximum speed of 55% by default. Perhaps if the fan had a more aggressive profile clock speeds would be higher. This again bodes well for custom cooled video cards, their GPU Boost could potentially be higher just due to having better cooling than the Founders Edition.