Dual mining refers to the process of performing different types of work with the same hardware. The term was popularized in the context of PoW mining where it referred to concurrently mining different cryptocurrencies by executing ther PoW hashing algorithms using the same GPU. In the context of Livepeer, dual mining can still involve using a GPU to mine a cryptocurrency like Ethereum, but it also involves using the GPU to transcode video as a video miner on the Livepeer network.
Why consider dual mining?
Dual mining can be considered to:
- Improve the utilization of GPUs
- This can be of particular interest to Livepeer video miners since unlike in other blockchain networks, there is not always work for the GPU to do in the Livepeer network
- Create an additional revenue stream with existing GPUs
One of the benefits of using transcoding as the additional workload in dual mining is that its usage of GPU cores is minimal relative to other potential workloads since most of the heavy lifting is done by the hardware encoder and decoder embedded in the GPU. See the Nvidia video encoding and decoding docs for more information on the separation of video encoding and decoding from the GPU cores.
Tradeoffs and considerations
There are still a few tradeoffs and points to consider when dual mining:
- In most cases, VRAM is likely to be the constraining factor for transcoding capacity. The more VRAM that is consumed by the other workload (i.e. ethash mining), the less streams that can be concurrently transcoded. So, GPUs that have more VRAM will have more transcoding capacity when dual mining
- There is still a performance tradeoff between the two workloads. For example, hashrate for ethash mining will linearly decrease as more streams are concurrently transcoded. The use of CUDA MPS with newer generation GPUs can help reduce the rate at which hashrate decreases - see the dual mining guide for more information
- If you are just transcoding right now, then dual mining another cryptocurrency can increase power consumption on your GPU especially if the other cryptocurrency uses a PoW hashing algorithm. So, in this case, the cost of electricity and cooling for your GPU should be factored in when considering dual mining
- If you are just mining a cryptocurrency like Ethereum right now, then transcoding is unlikely to increase the power consumption on your GPU based on previous testing