Complete overclocking tutorial for HiveOS & Windows

Getting a graphics card's overclock right means mining faster while using less power. In this tutorial video (in French) from early 2022, we go over the basics, then show you step by step how to overclock NVIDIA cards in HiveOS, on a rig with three RTX 30 cards, and in Windows with MSI Afterburner, on a non-LHR RTX 3070, mining Ethereum.

Overclocking basics

On an NVIDIA card, there are only three settings:

• Core clock, the frequency of the graphics processor: either as an offset from the stock value (+100, -200, -500…) or as an absolute value;
• Memory clock, the frequency of the card's memory;
• Power limit, which caps power consumption: in watts in HiveOS, as a percentage in Windows.

To judge a setting, look at efficiency: the hashrate divided by power consumption, in kH/W. The higher, the better. AMD cards are more complex: on an RX 6800, you also set the GPU, memory and memory controller voltages.

Settings depend on the algorithm and the memory

The right overclock changes with the coin you mine. On Ethereum, you mainly push the memory and lower the core clock (often -300 to -500). Cards with GDDR6X memory, such as the RTX 3080 and 3090, can then run into memory overheating. On Flux it is the opposite: memory left at its base frequency and core clock raised (+150 suggested, we often use +200). So when you switch coins, you need to revisit the overclock.

The memory brand matters too: the same card model can ship with Samsung, Hynix or Micron memory, and Samsung generally clocks higher. The hashrate.no website, for example, suggests about 1,800 for an RTX 3060 Ti with Hynix memory, versus 2,600 for an RTX 3070 with Samsung. Note that these values use the HiveOS format. In Windows, divide the memory frequency by two.

Overclocking your cards in HiveOS

In the worker, the Overclocking tab or the speedometer icon lets you set all cards at once or card by card: core clock, memory clock, fans and power limit. Our tip: apply the overclock 30 to 40 seconds after the miner starts, to avoid invalid shares at startup.

To find starting settings: a Google search such as "RTX 3080 HiveOS" (forums where miners share their results), YouTube, hashrate.no, or the Popular presets tab in HiveOS, which shows the values other miners use for a given coin and card.

On an unfamiliar card, we set the fans and a safety power limit to spare the power supply, leave everything else at zero, look for raw power first (the memory), then optimise consumption. To follow each change in real time, we open a remote console (Remote access, then Hive Shell Start) and type the miner command to display the miner logs. Also keep an eye on the load average, which must not exceed 1 (orange then red if a setting is wrong), and on the accepted share rate.

On our RTX 3080:

• memory at 2,400: 99.6 MH/s and 370 kH/W;
• power limit raised by 20 W: same hashrate, but consumption goes from 269 to 288 W and efficiency drops to 350 kH/W. Pointless;
• core clock locked at an absolute 1,060: about 218 W, 425 kH/W, still close to 100 MH/s. With an absolute value, frequency and voltage stay stable and the power limit becomes unnecessary;
• memory at 2,800: the card crashes ("CUDA exception… launch failed") and the rig goes offline: back to the previous setting.

Overclocking in Windows with MSI Afterburner

MSI Afterburner is the reference software. The first time you open it, click the Windows icon so that it starts with Windows and applies your settings. You enter the values, confirm, and can save them as profiles. GPU-Z complements it: stock frequencies, memory type and temperatures (Sensors tab). We also switch the fans to manual at 70%. The miner we use is T-Rex Miner.

Windows example: an RTX 3070 at 60 MH/s under 120 W

1. Stock settings: just under 50 MH/s for 180 W, i.e. 266 kH/W.
2. Memory +1,300 (equivalent to 2,600 in HiveOS): just over 60 MH/s, but more than 200 W. At +1,400 the hashrate reaches 62 MH/s without being stable, so we go back to +1,300. If the card also drives the Windows desktop, you lose 1 to 2 MH/s.
3. Core clock -500: no effect on hashrate, a few watts less and a slightly cooler card.
4. Power limit at 70%: about 153 W for 59–60 MH/s, i.e. 325 kH/W.
5. Power limit at 60%: 130 W for 60 MH/s, about 460 kH/W, and the temperature drops from 61 to 48 °C. At the minimum (45%), the card goes down to 100 W but only 38 MH/s: too low.
6. Core clock locked at 1,100: Afterburner can do it through the curve editor, but it is awkward. We instead add --lock-cclock 1100 at the end of the command line in T-Rex's .bat file, then run that file as administrator. Result: 60 MH/s for 118 W, 40 °C and over 500 kH/W.

These are the settings suggested by hashrate.no, which proves reliable.

What about today?

Since Ethereum moved to proof of stake in September 2022, Ethereum can no longer be mined with graphics cards and GPU mining income has collapsed: the settings above are mainly useful as examples. The approach, however, is still the right one: tune step by step, aiming for the best efficiency rather than just the highest hashrate.

To go further, see our HiveOS tutorial (worker, flight sheet, overclocking), our guide to debugging your mining rig and our tutorials page. To mine today, browse our ASIC miners.