How to mine CryptoNight based crypto currencies with Radeon RX Vega 56/64 GPUs

Updated to Cast XMR version 1.0.0 on April 24th, 2018

This guide describes how to mine CryptoNight/CryptoNote based crypto currencies like Monero (XMR), Bytecoin (BCN), DigitalNote (XDN) and Intense (ITNS) at highest mining rates with the AMD Radeon RX Vega 56/64 GPUs.

CryptoNight is the Proof-Of-Work (POW) hash algorithm used by many CryptoNote protocol based currencies to sign the blockchain transactions. The CryptoNight algorithm is designed to use a lot of memory and a lot of memory read/write operations. The idea is that it should have no big advantage to run the algorithm on number crunchers like GPUs or dedicated ASICs and perform equally well on general purpose CPUs.

Now the AMD Radeon RX Vega 56/64 GPUs has entered the field. Their new memory interface based on HBM2 memory delivers higher memory throughputs also in random access workloads which makes them the currently fastest and most efficient devices available to crunch CryptoNight hashes.

For comparison:

  • Intel Core i9-7900X (10 cores, 3.3 GHz): ~470 CryptoNight Hashes/s
  • AMD Ryzen Threadripper 1950X (16 cores, 3.4 GHz): ~1080 CryptoNight Hashes/s
  • Nividia Geforce GTX-1080TI: ~900 CryptoNight Hashes/s

The AMD Radeon RX Vega can crunch more than 1900 CryptoNight hashes per second with a power consumption of 150 watts.

With some more overclocking the RX Vega breaks the 2 KHash/s barrier with a power consumption of 250 watts.

Compare the price tags of the devices and it’s easy to calculate which gives the most bang for the buck.

How to setup a Radeon RX Vega 56/64 for optimal CryptoNight mining is described in the next steps.

The Miner Software: Cast XMR

We developed special CryptoNight mining software ‘Cast XMR’ for RX Vega GPUs. It utilizes OpenCL 2.0 and hand optimized low level code to take full advantage of the Vega architecture.

Read all about the latest version of Cast XMR here.

Cast XMR 1.0.0 for Windows (64 bit)

To run Cast XMR the typical miner command line has to be entered:

cast_xmr -S [pool server] -u [username or wallet address]

With the default Radeon Vega driver (at the time of writting driver version 17.9.2) and default ‘balance’ settings of AMD Global WattMan you will get about 1050 Hash/s. Which is already higher then with any other CryptoNight mining software.

cast xmr default driver

But to really get the Vega going some further steps can be done.

The AMD Blochchain Compute Driver

AMD released a special driver for Radeon GPUs which is called the ReLive Edition Beta for Blockchain Compute Driver Version the current version is 17.30.1029. It is called ‘beta’ but does the job for Vega 64 and Vega 56 GPUs.

The purpose of the driver is to optimize the card for compute workloads like machine learning and yes POW hashing for blockchains. What it exactly does is only know to the AMD engineers, a guess is that it dedicates more memory bandwith to the compute units and takes it away from the GPU rendering paths.

When installing do a ‘Clean Install’ and select to install the ‘Local Driver (17.30)’ otherwise you will probably end up with the wrong version of the driver.

Be aware for gaming the original driver has to be installed otherwise you will have really low framerates.

After installing the Blockhain Compute driver and firing up Cast XMR it will detect that the special driver is installed and use a further optimized kernel. Which will result in:

cast xmr blockchain driver default setting


cast xmr blockchain driver bug

If you get less then 1500 Hash/s you probably have to do following step:

Workaround: Toggle the HBCC Memory Segment

One anoying bug of the Blockchain driver seems to be that sometimes after a reboot it does not deliver full performance. A fix for it (if you know a better one, please let me know) is to toggle the “HBCC Memory Segment” option in the Radeon Settings from ‘disabled’ to any other setting or the other way around and press ‘Apply’. Close the mining app before doing so, otherwise you will get a furious crash!

cast xmr blockchain driver workaround

The settings will close and the driver seems to be reinitialized, after that in most cases it results in the correct hashrate. It also seems not to matter if HBCC Memory Segment is disabled or turned on. Though disabled would be the more logical state as for mining the HBCC feature is not needed.

GPU Core, Memory and Fan Settings

Now it is time to tweak the clocks to adjust the Vega GPU to the special mining workload. Go the Global WattMan section in the AMD Radeon Settings, flick the Performance Profile to “Custom” and adjust the values.

First make sure to adjust the fan for better cooling. Switch the “Temperature” switch to “Manual” and enter as target temperature 70. If the temperature goes above 70° the card starts throttling the clocks to protect from overheating and the hash rates will decrease dramatically. Cooler is always better as it reduce power consumption and protects the GPU.

The basic idea for overclocking is to increase the ‘Memory Clock’, reduce ‘GPU Clock’ as low as possible without throtteling the hash rate, reduce the ‘Power Limit’ as far as possible to prevent overheating and reduce power consumption but also not to stall the memory clock and thereby the hash rate.

We found following settings to be sweet spots, but try for yourself. The cooling conditions have probably a high influence on your optimal settings.

Vega 64 Hash Rates

1900 Hash/s with 200 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 1025 MHz
  • Power Limit: -23%

2000 Hash/s with 250 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 1095 MHz
  • Power Limit: 0

2050 Hash/s with 280 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 1105 MHz
  • Power Limit: +20%

Vega 56 Hash Rates

1900 Hash/s with 150 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 945 MHz
  • Power Limit: -22%

2000 Hash/s with 200 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 965 MHz
  • Power Limit: 0

2050 Hash/s with 225 watts power consumption

  • Core Frequency: -10%
  • Memory Clock: 990 MHz
  • Power Limit: +12%
cast xmr vega at 200 watts power consumption

For CryptoNight Mining Vega 56 or Vega 64?

After some testing it seems that the Vega 56 and Vega 64 are at least equal fast at CryptoNight hashing. Maybe because the memory part is nearly the same and that much compute is not really needed.

Both can peak perform more then 2050 Hashes/s.

But the Vega 56 achieves the same hash rate with about 50 watt less power consumption although or because the memory clock is 100 Mhz lower then on a Vega 64.

The Vega 64 is by far the more fiery card which means it gets hot really fast. With better cooling (like with the liquid cooled model) the Vega 64 maybe could run at higher memory rates and perform even better. But for now it always seems to throttle down itself after a few seconds to protect from overheating and gets very unstable at memory clocks above 1100 MHz.

With the current price difference and lower power consumption the RX Vega 56 is definitly the efficiency king at CryptoNight hashing.

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