How to Optimize Your GPU for Ethereum Mining
Ethereum GPU mining is back and — currently, at least — highly profitable. But there’s more to it than just firing up the software and letting it run in the background, especially if you’ve managed to procure one of the best graphics cards. Most of the graphics cards in our GPU benchmarks hierarchy can theoretically earn money right now, depending on how much you pay for power. However, you’ll want to tune your graphics card with the optimal settings, and the brand and card model can have a big impact on overall performance and efficiency.
First, let’s note that we’re not trying to actively encourage anyone to start mining with their GPUs. In fact, based on past personal experience that some of us have running consumer graphics cards 24/7, it is absolutely possible to burn out the fans, VRMs, or other elements on your card. At the same time, we know there’s a lot of interest in the topic, and we wanted to shed some light on the actual power consumption — measured using our Powenetics equipment — that the various GPUs use, as well as the real-world hashing rates we achieved. If you’ve pulled up data using a mining profitability calculator, our figures indicate there’s a lot of variation between power and hash rates. Don’t be surprised if your particular card doesn’t reach the level of performance others are showing.
We’re starting with the latest generation of AMD and Nvidia GPUs, but we’ll flesh things out with additional tests over the coming days (as warranted). There are a few things you should know before getting started. First, Ethereum GPU mining requires more than 4GB of VRAM, so if you’re still hanging on to an RX 570 4GB, it won’t work. Second, there are a lot of different software packages for mining, but we’re taking the easy route and using NiceHash Miner 126.96.36.199. It includes support for the most popular mining solutions, and it will even benchmark your card to determine which one works best. Except, it’s not always accurate, so we’ve standardized on NBMiner for the Nvidia GPUs and PhoenixMiner on the AMD GPUs. (Our test results are generally within a few percent of each other on either miner, but Phoenix did a bit better on AMD. YMMV.)
TOM’S HARDWARE GPU TEST PC
We’ve used our standard GPU testbed (listed to the right) for these tests, running a single GPU. This isn’t an optimal miner PC configuration, but it’s likely close to what most of our readers are using. You don’t need a high-end CPU, motherboard, or memory for mining purposes, and many larger installations will use Pentium CPUs and B360 chipset motherboards with more PCIe slots. The most important factors for a mining PC are power and cooling, as they both directly impact overall profitability. If you can keep your GPU and other components cool, they’ll last longer and not break down as often. Meanwhile, power can be very expensive for larger mining setups, and poor efficiency PSUs (power supply units) will generate more heat and use more electricity.
We’ve run these initial benchmarks using NiceHash Miner, including its built-in benchmark that’s required to get started. We tested each graphics card in stock mode, and then we also attempted to tune performance to improve overall efficiency — and ideally keep temperatures and fan speeds at reasonable levels. We let the mining run for several minutes before checking performance, power, etc., as often things will slow down once the graphics card starts to heat up.
It’s also important to note that we’re reporting raw graphics card power for the entire card, but we don’t account for the power consumption of the rest of the PC or power supply inefficiencies. Using an 80 Plus Platinum PSU, we should be running at around 92% efficiency, and wall outlet power consumption is typically about 50-80W higher than what we show in the charts. About 40W of power goes to the CPU, motherboard, and other components, while the remainder depends on how much power the GPU uses, including PSU inefficiencies.
There’s a lot to discuss with these charts, specifically, what do we mean by “tuned” performance. The answer: it varies, often massively, by GPU.
Let’s talk about the big picture quickly before we get into the details. The fastest GPUs for Ethereum mining right now are the RTX 3080 and RTX 3090, by quite a large margin. Our baseline RTX 3080 measurement got 85MH/s, and the baseline 3090 got 105MH/s. Additional tuning improved the 3080 performance to 93MH/s, while we had better luck overall with slightly lower 101MH/s on the 3090 FE.
Meanwhile, the RTX 3060 Ti and 3070 cards all started at close to 52MH/s — even though the 3070 is theoretically faster. That’s because Ethereum hashing depends quite heavily on memory bandwidth and perhaps somewhat on capacity. Overclocking the VRAM on those GPUs got performance up to nearly 60MH/s. AMD’s RX 6000 cards started at close to 60MH/s, and with tuning, we achieved 65MH/s — there wasn’t much difference between the three AMD GPUs, mostly because they’re all using the same 16GB of 16Gbps GDDR6 memory.
You can see the power chart (which is reversed because it would take extra effort to get my charting tool to do low to high), but the overall efficiency chart is more important than raw power use. Again, the RTX 3080 and 3090 place at the top, with the Colorful RTX 3080 Vulcan taking first place overall. But AMD’s RX 6800, 6800 XT, and 6900 XT are right in the mix after tuning.
Finally, we have temperatures. These are GPU core temperatures, but they’re actually not the critical factor on many of the cards. AMD’s cards ran hot at stock settings, but all of the cards benefit greatly from tuning. More importantly, while we couldn’t get GDDR6 temperatures on the 3060 Ti and 3070, we did get VRAM temps on the 3080 and 3090 as well as the AMD cards. At stock, the 3080 and 3090 Founders Edition cards both hit 108-110C on the GDDR6X, at which point the GPU fans would kick up to nearly 100%. The cards settled in at 106 degrees Celsius, with GPU clocks fluctuating a bit. AMD’s RX 6000 cards also peaked at around 96C on their GDDR6 at stock, but tuning dropped VRAM temps all the way down to around 68-70C. This brings us to the main item of interest.
How to Tune Your Graphics Card’s Ethereum Mining Performance
Let’s start by noting that every card model is different — and even cards of the same model may vary in performance characteristics. For the 3080 and 3090 cards with GDDR6X memory, keeping that cool is critical. We’ve seen examples of cards (specifically, the EVGA RTX 3090 FTW3) that can run at up to 125MH/s, while the memory sits at around 85C. That’s because EVGA appears to have put a lot of effort into cooling the memory. Without altering the cards, the Nvidia 3080/3090 Founders Editions let the memory get very hot while mining, which can dramatically hinder performance and/or reduce the card’s lifespan. Let’s take each card in turn.
GeForce RTX 3090 Founders Edition: While technically the fastest card for mining that we tested, we really don’t like the idea of running this one 24/7 without hardware modifications or serious tuning. At stock, the fans end up running at 100% to try to keep the GDDR6X below 110C, and that’s not good. We dropped the GPU core to the maximum allowed -502MHz, set the memory clock to -252MHz, and put the power limit at 75%. That gave us a GDDR6X temperature of 102C, which is still higher than we’d like, and performance remained over 100MH/s. Power use also dropped to 258W, which was lower than the RTX 3080 FE, yielding the second-highest overall efficiency of the cards we’ve tested.
GeForce RTX 3080 Founders Edition: Tuning this card was very similar to the 3090 FE. It doesn’t like stock settings, as the GDDR6X gets very toasty. We again dropped the GPU core the maximum allowed (-502MHz), left the memory clock alone, and put the power limit at 90%. That resulted in the same GDDR6X temperature of 102C as the 3090 FE, and performance was only slightly slower at 93MH/s. It was actually less efficient due to the higher power limit, and further tuning might be possible (e.g., you may have better results at 70-80% power limit). We’d prefer using an RTX 3080 with better GDDR6X cooling, however.
Colorful RTX 3080 Vulcan: This card has better VRAM cooling than Nvidia’s reference card, so the memory didn’t get quite as hot. However, we still found we achieved the best result by dropping the power limit to 90% and then setting the GPU core clocks to the minimum possible value in MSI Afterburner (-502MHz). Then we overclocked the memory by 750MHz base clock, which gave a final speed of 20Gbps (the Ampere cards seem to run at 0.5Gbps below their rated memory speed when mining by default). That yielded average GPU clocks of just 1425MHz (down from 1920MHz), but overall performance increased to 93MH/s, while fan speed, GPU temperature, and power consumption all dropped. (We tried a similar approach on the 3080 FE, but it wasn’t quite as successful due to the memory temperatures. The takeaway being that card design matters more than raw specs.)
GeForce RTX 3070 Founders Edition: The RTX 3070 and RTX 3060 Ti have the same 8GB of 14Gbps GDDR6, and as we’ll see with the AMD GPUs, that appears to be the limiting factor. We probably could have tuned the GPU clocks better, but these were the first cards we tested, and we’re learning as we go. (We’ll update after some additional testing to see if dropping GPU core clocks would reduce temperatures without lowering the hash rate.) The main thing for improving performance on the 3070 was to boost the GDDR6 clock. We were able to add 1000MHz, giving a 16Gbps effective speed in theory, but the memory actually ran at 15.6Gbps (vs. 13.6Gbps at stock settings). We also increased the power limit and overclocked the GPU by +125MHz, which caused power consumption to increase a bit, but again we might be able to tweak the clocks for better power use without reducing performance.
GeForce RTX 3060 Ti Founders Edition: As with the 3070, we bumped the memory speed up as the main change to improve performance. We went from stock to +750MHz (which we usually have to use for gaming overclocks), giving a maximum speed of 15.5Gbps. However, we noticed after the fact that for GPU compute, there appears to be a 400MHz negative offset, so we were only running the GDDR6 at 15.1Gbps, which might explain the slightly lower performance compared to the 3070. We’ll retest and update our results in the near future.
Asus RTX 3060 Ti TUF Gaming OC: This is mostly here to show that, unlike the 3080 and 3090, third party cards aren’t markedly different in hashing performance with the 3060 Ti GPU. Our tuned settings ended up with higher clocks and more power use than the 3060 Ti Founders Edition, giving slightly higher (by 2.5%) better hashing performance. That suggests perhaps GPU clocks do matter more on these Nvidia cards, though optimal efficiency might still be at lower GPU core speeds.
Radeon RX 6900 XT (Reference): Tuning all three of AMD’s reference RX 6000 cards ended up very similar. The GPU clocks can go very high at stock, but the memory bandwidth appears to be the main bottleneck. Running with GPU clocks of 2.2-2.5GHz just wastes power and generates heat without improving performance. We cranked the power limit to the maximum 115% just to ensure the VRAM wasn’t being held back, then set the memory at +150MHz (the maximum allowed in Radeon Settings), enabled fast RAM timings, and dropped the maximum GPU clock down to 70%. That gave us final clocks of 1747MHz compared to 2289MHz at stock and about 8% higher hash rates overall. More importantly, power consumption took a massive dive, and efficiency improved to one of the better results in our testing. But this actually isn’t AMD’s best overall showing.
Radeon RX 6800 XT (Reference): Same approach as above, but due to differences in the core configuration and … honestly, we’re not sure what the deal is, but we ended up with an optimal maximum GPU frequency setting of only 50% this time, which gave us clocks of 1206MHz instead of 2434MHz — and performance still went up, matching the RX 6900 XT and RX 6800. At the same time, power requirements dropped substantially, from 281W to 186W. Whatever is going on behind the scenes, it appears different AMD Navi 21 GPUs run optimally at different “maximum frequency” settings. Like Nvidia, AMD’s GPUs are largely limited in performance by their memory speed, and without tools to overclock beyond 17.2Gbps, there’s not much to be done.
Radeon RX 6800 (Reference): With only 60 CUs (compared to 72 on the 6800 XT and 80 on the 6900 XT), you might expect the 6800 vanilla card to end up slower. However, the memory proves the deciding factor once again. We set the GPU power limit at the same 115%, which does make a difference, oddly — average power dropped about 15W if we set it to 100%, even though the card was running well below the official 250W TGP. We also maxed out the memory slider at +150MHz (17.2Gbps effective), and this time achieved optimal performance with the GPU set to 75% on maximum clocks. That resulted in a 1747MHz clock compared to 2289MHz at stock, but fan speed was higher this time. That’s because we set the fan to run at 40% at 50C, 60% at 60C, 80% at 70C, and 100% at 80C — and it ended up at 50% speed, which is perhaps more than is required, but we feel it’s better safe than sorry if you’re looking at 24/7 mining.
Comparing Profitability and Performance
We’re just getting started, but after all of the testing we’ve completed so far, one thing we want to point out is that the NiceHash Profitability Calculator is … well, let’s just call it generous. It’s not like NiceHash has a vested interest — like a few percent of all commissions — to get people mining with its software, right? Actually, it’s not all bad, but our results definitely don’t match up on some GPUs. Here’s the quick summary of discrepancies, and again, this is without accounting for PSU inefficiency. We’re using the optimal tuned settings for our own results, and obviously some cards with the same GPU perform better than others. But we’re mostly looking at reference models, and our results don’t quite match up with NiceHash’s figures.
|TH Hashrate||NH Hashrate||% Difference||TH Power||NH Power||% Difference|
|RTX 3090 FE||100.8||120||-16.00%||258||300||-14.00%|
|RTX 3080 FE||93.2||98||-4.90%||276||240||15.00%|
|RTX 3070 FE||58.8||60.6||-3.00%||204||160||27.50%|
|RTX 3060 Ti FE||56.5||60.5||-6.60%||194||180||7.80%|
|Colorful RTX 3080||93.4||98||-4.70%||221||240||-7.90%|
|Asus RTX 3060 Ti||57.9||60.5||-4.30%||205||180||13.90%|
|RX 6900 XT||64.6||64||0.90%||183.3||220||-16.70%|
|RX 6800 XT||64.5||64.4||0.20%||186.3||190||-1.90%|
So, that’s interesting for sure. The RTX 3090 Founders Edition is definitely not the best sample of mining performance, and wherever NiceHash’s number comes from, it’s nearly 20% higher than what we got, but also used 16% more power — or if you prefer, our numbers were 16% slower while using 14% less power. On the 3080, the FE ended up just 5% slower while using 15% more power, but the Colorful card was 4% slower while using 8% less power. That’s one of the clear cases where the model of the card used makes a big difference. We were relatively close on the 3060 Ti performance but not so much on power, while our 3070 power use was much higher than NiceHash’s 160W figure. Maybe we can match up better on those two GPUs with additional tuning, but the 3090 and 3080 cards we tested definitely don’t match up with the supposed profitability figures.
Shifting over to AMD, things look a lot closer on performance — we’re within 2% across all three cards and actually came out slightly ahead. Even better, we achieved our results while using less power than what NiceHash shows. The current thinking for a lot of miners is that Nvidia’s RTX 30-series cards are superior to AMD, but that’s really only true if you look at pure hashrates. Factor in power efficiency, and things are much closer. Not like you can buy any of these GPUs right now — unless you’re willing to fork out a lot of money or have some good industry contacts for building your mining farm.
Should You Start Mining?
This brings us to the final point we want to make. Suppose you already have a graphics card and want to mine using your GPU’s spare cycles. In that case, it’s currently worth considering, particularly if you live in an area where power isn’t super expensive. You could theoretically net over $10 per day from the right 3080 or 3090 card, and $7.50 or so per day with one of the Big Navi or lower-tier Ampere GPUs. If you’re looking for the best option for mining, from the perspective of paying off the GPU as quickly as possible, the RTX 3060 Ti would be the card to get — or at least, it would be if you could find it anywhere for less than $900. No, that’s not a typo, and no, you shouldn’t pay $900 for a 3060 Ti!
Here’s the thing: cryptocurrencies are extremely volatile. Right now, Ethereum’s price is up 67% just in the past month, and 7% in one day. It’s also up 300% during the past quarter, and 750% since one year ago. This means that, as fast as the price has shot up, it could plummet just as quickly. If you’re looking at $10 per day per GPU in mining profits and thinking it’s only three months to break even, you’re assuming the price and profitability will remain steady. It won’t. There’s a chance it could actually go up, but the opposite is more likely given the recent jump in pricing. Just ask the GameStop ‘investors’ how that worked out if you think the sky’s the limit.
Again, if you already have a GPU, putting it into service isn’t a bad idea. Paying extreme prices for mid-range hardware to try and build your own personal mining mecca, on the other hand, is a big risk. You might do fine, you might do great, or you might end up with a lot of extra PC hardware and debt. Plus, what about all the gamers that would love to buy a new GPU right now and they can’t? Somebody, please think of the gamers!
Anyway, there’s more to come. We’ll check out some previous-generation GPUs as well, and RX 5700 series, in particular, seems promising. If you’ve got one of the previous generation Turing or Navi cards already, you might not be able to make quite as much from mining, but even GTX 1070 and RX 570 8GB cards can currently do over $3 per day. Just remember to account for power costs and cash out enough coins to cover that, and at least you won’t get caught holding the bag.
#Optimize #GPU #Ethereum #Mining