ASIC device usually has much better mining performance than graphics card. It is more energy-saving and has a much higher hashrate.
The Canaan AvalonMiner 821 was produced by Canaan and released in 2018. This miner consumes 1200W, producing 11.5 Th/s of hashrate with the sha-256 algorithm, which makes this device almost (if not at all) useless. We do not recommend buying this device for mining nowadays.
The most profitable coins to mine using AvalonMiner 821: