OpenCL Setup

Using OpenCL is an optional but highly recommended feature for running MMX.
Offloading the verification of the VDF to a GPU or iGPU can increase both performance and power efficiency.

Once the blockchain is synced, you will see these lines:

[Node] INFO: Verified VDF for height 239702, delta = 10.111297 sec, took 0.089002 sec.

Which indicates that your node is now verifying the current VDFs as they are received. Your GPU would now be utilized every ~10 seconds.

If OpenCL is not being utilized for VDF verification, you should see relatively high CPU usage across all cores every ~10 seconds.

If you are running a Timelord (the default is off), you will see high CPU usage on at least one core in any case, even if your GPU is used for verification.

Note: During initial blockchain sync, CPU usage can be high in any case.

Example Hardware and times spreadsheet: https://docs.google.com/spreadsheets/d/1NlK-dq7vCbX4NHzrOloyy4ylLW-fdXjuT8468__SF64/edit?pli=1&gid=618383284#gid=618383284

OpenCL for Intel iGPUs

Intel iGPUs prior to 11th gen are not sufficient for mainnet. Intel’s desktop iGPUs have much fewer compute units than their mobile counterparts, so only the mobile SKUs in laptops/mini-PCs will be suitable for OpenCL VDF verify. 11th gen and newer desktop CPUs with the SHA instruction set can get decent performance on the CPU cores without OpenCL.

Ubuntu 20.04, 21.04

sudo apt install intel-opencl-icd

Ubuntu ppa for 18.04, 20.04, 21.04

sudo add-apt-repository ppa:intel-opencl/intel-opencl
sudo apt update
sudo apt install intel-opencl-icd

If the above doesn’t work, you can try installing the latest drivers: https://dgpu-docs.intel.com/installation-guides/ubuntu/ubuntu-focal.html

Make sure your iGPU is not somehow disabled, like here for example: https://community.hetzner.com/tutorials/howto-enable-igpu

OpenCL for AMD GPUs

Ubuntu:

Download installer (with wget) from https://repo.radeon.com/amdgpu-install/latest/ubuntu/

Change directory to the Download folder and install with sudo dpkg -i amdgpu-install*.deb

sudo apt install rocm-opencl

Follow on-screen instructions and then run:

sudo apt update
sudo apt upgrade

Arch Linux:

sudo pacman -S opencl-amd

Mesa drivers with opencl drivers do seem to work, but performance is very poor (VDF verification >4x longer).
To install mesa drivers:
Ubuntu:

sudo apt install mesa-opencl-icd

Arch:

sudo pacman -S mesa mesa-utils opencl-mesa

Windows: https://google.com/search?q=amd+graphics+driver+download

OpenCL for Nvidia GPUs

Due to the massive generational leap in compute performance, the Maxwell generation (900 series Geforce, M-series and some K-series Quadro) should be the minimum consideration for Nvidia GPUs.

Install Nvidia drivers:

Ubuntu

sudo apt install nvidia-driver-470
sudo apt install nvidia-driver-565

Version 470 still works with older Kepler cards like a Quadro K2000. Use latest version for newer GPUs.

Arch Linux

sudo pacman -S nvidia nvidia-utils opencl-nvidia

For older GPUs, use drivers from the AUR:

# Kepler series newest driver: 470xx
yay -S nvidia-470xx-dkms nvidia-470xx-utils opencl-nvidia-470xx

# Fermi series newest driver: 390xx
yay -S nvidia-390xx-dkms nvidia-390xx-utils opencl-nvidia-390xx

AVX2 Optimizations

VDF verification is now optimized for CPUs that support AVX2 and acceleration is done automatically when starting a node.

To disable VDF verification done on GPU with OpenCL and force the CPU to do it, run ./run_node.sh --Node.opencl_device -1 when running your node.

Or for a more permanent solution, edit config/local/Node.json and set opencl_device value to -1.