Overclocking
Default GPU Frequency
Before we look at performance, we need to find out the actual real-world gaming frequency the video card performs. With both NVIDIA and AMD GPUs today, the GPU frequency is very dynamic. What may be quoted as the “Boost Clock” is not necessarily the performance it will actually run at. Typically, GPUs today can exceed the “Boost Clock” dynamically. We need to find out what it actually runs at, in this way we can see how well things like cooling and power headroom are working.
To do this we will record the GPU clock frequency over time while playing a game. We use Cyberpunk 2077 for this with a very long manual run-through at “Ultra” settings. We also record GPUz sensor data to look at GPU temperature, Voltage, and Power.
The default GPU Boost clock on the GIGABYTE GeForce RTX 3090 GAMING OC is 1755MHz. According to our gaming graph above the actual clock speed seems to stay mostly between 1755-1785MHz. It does dip a few times below 1755MHz briefly, the lowest being 1725MHz for just the briefest of seconds. Averaging out this clock speed the average is 1780MHz. This seems to be just on spec and doesn’t boost much above the specified boost clock. This is higher though than the Boost of a Founders Edition. Therefore, our baseline for overclocking will be 1780MHz average clock speed.
According to our GPUz results, you can see that at default the GPU Temperature is 62c at 71% and 69% fan speeds. The GPU Voltage is 1.0680V and the TDP is at 96%.
Overclocking GIGABYTE RTX 3090 GAMING OC
To overclock the GIGABYTE GeForce RTX 3090 GAMING OC video card, we are using the manufacturer-provided overclocking software. In this case, it is GIGABYTE AORUS ENGINE 2.0.1.
You can see that with GIGABYTE AORUS ENGINE we are only able to increase the Power Target by 5%. It goes from 100 to 105 and that is it. That doesn’t leave us much room to improve, we are going to hit the TDP limits very quickly with this video card. There is just not enough headroom here to raise the GPU Voltage. It is best to leave GPU Boost to manage GPU Voltage and just raise GPU BOOST clock and Memory Clock as much as possible.
In doing so we managed to find +100 on the GPU BOOST to be the highest we could set before it would lock up. This resulted in a GPU BOOST of 1855MHz. In addition, with the GDDR6X memory, we managed to boost that from 19.5GHz up to 20.5GHz, which is impressive for this memory.
Even the best of it can only hit around 21GHz at times, so for this card, that frequency is very good. This brings the memory bandwidth up from 936.5GB/s to 983.8GB/s. The video card’s performance isn’t memory-bound anyway; engine clock speed makes the most difference in overclocking performance.
According to the graph of real-world frequency while gaming our overclock is between 1905MHz-1935MHz. This is much higher than the 1755-1785MHz we were getting before. The average before was 1780MHz, the average now with the overclock is 1925MHz. That is an increase of 145MHz on average or an 8% GPU overclock.
GPUz Sensor Data Overclocked
Here is the GPUz sensor data with the video card overclocked. Overclocked we can see that the GPU Temperature is 53c at 100% fan speeds. The temperature is not holding back the overclock potential. The TDP is maxed out at the 105% which we knew we would hit very quickly with this video card, there just isn’t much headroom. The GPU Voltage did increase automatically with GPU Boost, it is now running at 1.0810V versus 1.0680V at default. Therefore, GPU Boost is managing GPU Voltage and raising it for us to hit this high of a GPU Clock speed. This is also why we are running into the TDP limit so quickly.
