Detailed Power Consumption Testing
When we started dissecting the power consumption concerns around the Radeon RX 480, that have since been mostly addressed by AMD with a driver fix and new control panel option, I knew this meant a much more strenuous power testing process going forward. With the GeForce GTX 1060 Founders Edition, I duplicated the exact power test and scenarios we used with the RX 480 in order to help users better understand the differences between them.
How do we do it? Simple in theory but surprisingly difficult in practice, we are intercepting the power being sent through the PCI Express bus as well as the ATX power connectors before they go to the graphics card and are directly measuring power draw with a 10 kHz DAQ (data acquisition) device. A huge thanks goes to Allyn for getting the setup up and running. We built a PCI Express bridge that is tapped to measure both 12V and 3.3V power and built some Corsair power cables that measure the 12V coming through those as well.
The result is data that looks like this.
What you are looking at here is the power measured from the GTX 1080. From time 0 to time 8 seconds or so, the system is idle, from 8 seconds to about 18 seconds Steam is starting up the title. From 18-26 seconds the game is at the menus, we load the game from 26-39 seconds and then we play through our benchmark run after that.
There are four lines drawn in the graph, the 12V and 3.3V results are from the PCI Express bus interface, while the one labeled PCIE is from the PCIE power connection from the power supply to the card. We have the ability to measure two power inputs there but because the GTX 1080 only uses a single 8-pin connector, there is only one shown here. Finally, the blue line is labeled total and is simply that: a total of the other measurements to get combined power draw and usage by the graphics card in question.
From this we can see a couple of interesting data points. First, the idle power of the GTX 1080 Founders Edition is only about 7.5 watts. Second, under a gaming load of Rise of the Tomb Raider, the card is pulling about 165-170 watts on average, though there are plenty of intermittent, spikes. Keep in mind we are sampling the power at 1000/s so this kind of behavior is more or less expected.
Different games and applications impose different loads on the GPU and can cause it to draw drastically different power. Even if a game runs slowly, it may not be drawing maximum power from the card if a certain system on the GPU (memory, shaders, ROPs) is bottlenecking other systems.
First, let’s look at our total power draw numbers.
This graph, though a bit hard to read at a single glance, shows the power consumption and efficiency of the GTX 1060 and GP106 at work. The blue line at the bottom is the GeForce GTX 1060, with its 120 watt TDP, drawing just 115 on average through this section of our Rise of the Tomb Raider testing. Interestingly, the next highest power draw comes from the GTX 1070 (yellow line), which hovers just under 140 watts.
The GTX 980 crosses past 160 watts and bounces up towards 180 watts in several instances, and with the expected equivalency of performance to the GTX 1060, makes the efficiency of Pascal and the 16nm process all the more impressive. The Radeon RX 480 is hitting every bit of its 150 watt TDP in this test, showing a full 35-40 watt delta between the two competing products.
The situation is similar in our The Witcher 3 testing; the GTX 1060 is pulling 105-110 watts combined while the RX 480 is more in the 155 watt range.
How does the power distribution break down between the motherboard slot and 6-pin power connection with the GeForce GTX 1060 Founders Edition?
Using The Witcher 3 once again, we can clearly see that the 6-pin connection draws as much as 65 watts of power, the motherboard +12V source peaks at about 53 watts, well under the 66 watt limit for +12V.
One of the worst case scenarios for power draw we saw with the Radeon RX 480 was in Metro: Last Light running at 4K. Even though this class of cards isn’t really meant for 4K gaming, we put the GTX 1060 FE through the same torture. In a couple of instances the total power draw did spike over 120 watts and hit 124 watts. Still, the power draw from the 6-pin connector never crossed 70 watts and from the motherboard +12V, it never crossed 57 watts.
Current draw from the same testing scenario shows a peak output of just 4.8A, well below the 5.5A limit of PCI Express certification.
For those of you that dive into overclocking, how does that change power draw? I ran the same Metro: Last Light testing at 4K with the GTX 1060 running at our +200 MHz offset with voltage cranked up in PrecisionX.
Power draw definitely went up, with total consumption going to 143 watts, 79 watts from the 6-pin connection and 64 watts from the +12V on the motherboard PCI Express slot. Our current draw numbers show 5.4A was the maximum that the GTX 1060 was drawing in this same state.
It is clear from our testing and from the results shown here that the GeForce GTX 1060 Founders Edition does not suffer from any similar power concerns that the Radeon RX 480 launched with.