Introduction

AMD launched the Radeon RX 6000 series of video cards on November 18th, 2020 known as Big Navi.  At the very high-end is the $999 Radeon RX 6900 XT.  Right below that is the $649 Radeon RX 6800 XT and then below that is the $579 Radeon RX 6800.  We just recently overclocked the Radeon RX 6800 XT and achieved better performance that made it compete well with the GeForce RTX 3080 FE.  Now it is time to overclock the $579 Radeon RX 6800 video card.

At $579 the Radeon RX 6800 is in an odd place.  It is much more expensive than NVIDIA’s GeForce RTX 3070 FE at $499 MSRP, and it’s much cheaper than the GeForce RTX 3080 FE at $699 which is where the Radeon RX 6800 XT competes.  So, while you would think the GeForce RTX 3070 FE might be the right comparison, in truth the Radeon RX 6800 and GeForce RTX 3070 FE are $80 apart, so we’d hope the Radeon RX 6800 is faster at that kind of price difference. 

There is just nothing from NVIDIA at the moment that compares at that price point.  Therefore, in this review, we will include both the GeForce RTX 3070 FE and GeForce RTX 3080 FE to show where the Radeon RX 6800 fits in-between.  We will also include the Radeon RX 6800 XT to give a perspective of how far apart they are.

You can read about the AMD Radeon RX 6800 launch in our review.  We will give you a brief overview before we dive into overclocking.    The $579 Radeon RX 6800 is based on AMD’s new RDNA2 architecture and manufactured on TSMC 7nm.  It has 60 Compute Units, 60 Ray Accelerators, 3,840 Stream Processors, 96 ROPs, and 128MB of AMD Infinity Cache.  The Game GPU Clock is set at 1815MHz and the Boost GPU Clock (up to) is 2105MHz.  It has 16GB of GDDR6 at 16GHz on a 256-bit memory bus providing 512GB/s of memory bandwidth.  The Board Power is rated at 250W.

How to Overclock the Radeon RX 6800

How do you overclock the AMD Radeon RX 6800 video card?  Before we find out how high it can overclock, we first need to find out what it runs at by default.  AMD has two different clock domains.  There is the Game Clock and the “Max” Boost Clock that the GPU is capable of boosting to in certain workloads.  For the most part, the Game Clock of 1815MHz is what you should expect while gaming.

However, because of the dynamic nature of the GPU frequency, it can clock up to 2105MHz while gaming.  Basically, the clock speed will be anywhere between 1815-2105MHz while gaming.  It will jump all over the place based on many sensor inputs about thermals, temp, power, voltage, and even the level of workload and types of workload that is stressing different parts of the GPU.

In the graph above you can see that the default GPU frequency for the Radeon RX 6800 while gaming jumps around a lot.  It is anywhere from 1935MHz to 2290MHz.  For the most part, it’s around the 2215-2255MHz range.  If we take an average of all the frequencies shown above the average clock is 2218MHz.  That is much higher than the 1815MHz game clock range and even exceeds the 2105MHz max boost clock.  So, while gaming, this video card already reaches beyond the boost clock.

According to GPUz, it is doing this at a GPU Voltage of 1.025V at 51% fan speed and 72c GPU temp.  GPU Chip Power Draw is 204W.

Highest Overclock on Radeon RX 6800

Overclocking the AMD Radeon RX 6800 is limited at the moment in what software programs support overclocking.  At this time, MSI Afterburner will not work.  We have to rely on the features available in the AMD Radeon Software itself for overclocking.  Thankfully, these days that support and features are very comprehensive.  It allows customizing power target, fan speed, GPU frequency, and memory frequency and timings.  It does not, however, allow us to raise the Voltage at the moment on the Radeon RX 6800 GPU.  Our maximum overclock is shown in the screenshot below.

The first thing to note from the AMD Performance Tuning is that we were able to manually overclock.  We were able to increase the Power Tuning by 15%.  This is essential, and the most we could raise it.  Second, we were able to turn on advanced control for the fan speed and raise it to 100% at all times and also turn off the Zero RPM fan feature.  We set the fan at 100% to ensure the highest overclock.

GPU Frequency

Next up is the GPU frequency, this is where it gets a little complex.  There are two options, a Min Frequency and a Max Frequency.  On the AMD Radeon RX 6800 XT we ended up raising both the Min Frequency and Max Frequency to hone in a higher overclock.  On the Radeon RX 6800 though, we found that we only needed to raise the Max Frequency.  There was no improvement to the overclock by raising the Min Frequency, so we ended up just leaving it at default.

Pushing the Max Frequency up, we tried the highest setting on the slider which is 2600MHz.  We were actually able to game for a few minutes, but then it would lock up.  While it was working, we noticed frequencies of about 2560MHz.  However, this was just a bit too high to be stable, as we said games would crash after a few minutes.  We backed the frequency down to 2500MHz on the slider, and found this setting to be very stable. 

We tried to set it a bit higher to 2500MHz Min Frequency and 2700MHz Max Frequency, and while this setting actually worked, it actually lowered game performance at 4K and with Ray Tracing.  So, when we backed it down to 2400MHz-2600MHz then we saw the most positive performance increases.  We’ll see what turns out in real-world frequency below.  As for the GPU Voltage, we were not able to increase it at all, it was locked at a maximum of 1150mV. 

Memory

On the memory side of things Performance Tuning only let us set the memory up to a maximum of 2150MHz.  The default speed is 2000MHz.  The slider simply would not go any higher, so the memory is locked at a maximum of 2150MHz.  This results in a maximum memory frequency of 17.2GHz versus the default of 16GHz.  That boosts the memory bandwidth up to 550GB/s up from the default of 512GB/s.  We think the memory might be capable of more, but it’s simply software locked.

Overclock Comparison Graph

Here is the graph that shows how the overclock compares to the default frequency.  The orange line is the overclock, blue is the default.  You will notice that the overclock is definitely higher, it is hitting as high as 2445MHz.  At times we are seeing clock speed increases in the order of about 230MHz more which is quite significant.  The overall average of the clock speed frequency above is 2372MHz, which compared to the default of 2218MHz is an overclock of 7%. 

GPUz

According to GPUz, the Voltage remains at 1.025V, GPU temperature is 61c and GPU Temperature Hot Spot is 81c at 88% fan speed (for some reason it didn’t quite get up to 100% even though we set it.)  The GPU Chip Power Draw increases to 233W.

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Brent Justice

Brent Justice has been reviewing computer components for 20+ years, educated in the art and method of the computer hardware review he brings experience, knowledge, and hands-on testing with a gamer oriented...

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3 Comments

  1. I find the temperature testing of the new AMD cards a bit interesting. It seems they do really well in open environments as far as temperatures go. Inside a case, even with good airflow, the temperatures are far outside of what I’ve seen in bench reviews.

    For instance, I have a 6800 inside a Lian Li O11D-XL | 3 x Noctua NF-S12 at the bottom as intake, 1 x Noctua NF-S12 rear exhaust, top dust filter removed; the 6800 on the stock cooler at stock settings hit 84C GPU and 101C junction (hot spot). With a 6900XT cooler swapped onto it, also at stock settings, it hit 72C GPU and 86C junction (hot spot). With the 6900XT cooler on, I was able to put the GPU slider all the way to 2600MHz and VRAM to 2150MHz with a 76C GPU and 91C junction (hot spot) temp.

  2. While I prefer the 3070 myself and hopefully get one in the near future. I think the 6800 is a great value. Its substantially faster than the RTX3070 on pretty much all counts except RT.

    Overclocking brings it close to its bigger brother and can even beat the 3080 in a few cases.

    BTW from what I’ve seen both the 6800 and 3070 can be found at over $900 so the retail price difference is moot.

  3. Now that I’ve taken some tips from the reviews here I can add my results. With my case closed, the only airflow is the 3 fans on a 360mm radiator at the front for intake and 3 fans on another 360mm radiator in the back for exhaust. The fans are set to adjust speed according to the CPU temp (currently the only part cooled by the loop). I have an aggressive fan curve on the 6800, starting at 30% ( no zero fan) and hitting 100% by 60C.

    I keep the power limit and memory maxed at +15%. With the case closed I can actually undervolt the chip to 975 mV and set the max to 2450, which seems to average about 2350 in game. In the closed case, Tjunction gets as high as 106C ( usually 101-102) and Tchip runs 84-86C.

    To go higher I have to open the case and set the voltage to stock 1025 mV. Then the chip will run with a max speed of 2550 and averages about 2450 in game. Temps are much better with the case open – Tjunction maxes out at 86C and Tchip stays below 70C – usually around 64C.

    I’m still hoping to grab a 6800XT or 6900XT, but if that doesn’t happen in the next couple of weeks, I’ll add the 6800 to the water loop and see how it does.

    Igor’s lab has some BIOS mod tools that might unlock the real potential, but the current versions seem to still be targeted toward the 5700 cards. If they update to add explicit 6800 support, I may get to try unlocking the memory and power limit boosts.

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