Before we proceed, it should be noted that there are two Radeon RX 480 versions, one with 4GB that runs at 7 Ghz and a more expensive 8GB model running at 8 GHz.
RX 480 8GB test
We tested the ASUS Radeon RX 480 8GB with 8 GHz video memory and in this review we will sum up our results for ETH mining. Compared with 8GB 8 GHz version, the 4GB 7 GHz model will be slower by about 2-3 Mhs. So, we recommend you to buy the 8GB version for mining purposes.
We used Claymore Dual Miner with default settings: 1266 MHz graphics processor frequency and 8 GHz video memory frequency. We resulted in 24.7-24.8 MHS with 108 watts power consumption and 177 watts real power consumption. Considering the 80 Plus Gold PSU efficiency, we can say that with default settings its power consumption is 150 watts. During ETH mining with default frequency settings, the frequency is stable at about 1240 MHz, never reaching the maximum 1266 MHz. So, our analysis is correct.
Reaching the 150 watts power limit, a plussage by several percent allows to achieve full acceleration to a total of 1266 MHz… While this may not be important for ETH mining, it can be crucial for production of other cryptocurrencies.
In dual mining mode, you can simultaneously mine ETH and DCR – 24.3 MHS for ETH and 365 MHS for Decred (with default intensity = 30). Later we increased Decred productivity to 35, but ETH hashing capacity dropped to about 24 MHS, while Decred hashrate leaped to about 450 MHS. The RX 480 is completely functionable in the dual-mining mode and with a slight drop in Ethereum hashrate, you get a significant increase in Decred hashrate.
When we tried overclocking, we managed to increase the video memory working frequency to the maximum, which in our case was 9 GHz (the overclocking software and driver has are limited to 9 GHz so that was all we could get). With a 9 Ghz video memory, RX 480 results in 28 MHS hashrate for ETH mining.
If we managed to overcome the 9 Ghz limit, the hashrate could be higher. However, at the moment neither the AMD WattMan nor Asus tools allow us to do this. With video memory overclocking, the power consumption increased by about 7-8 watts, but in case of ETH mining it was definitely worth it.
We were a little disappointed with the lack of overclocking for GPU frequency, which has a 1340 MHz voltage margin. Of course, such overclocking does not really make any difference for ETH mining, and in fact, if you only want to mine ETH, the clock speed should even be slightly lowered. Also we were not very happy with RX 480 cooling and heat removal. AMD set the fan speed so that the GPU remained quiet and very hot, which is not suitable for mining.
The best solution would be to set the fan speed at 80%, which would give us a moderate temperature and not too much noise. By setting fan speed to 80%, you can expect a temperature of about 72 degrees Celsius on your GPU, which is not very good if you are mining 24/7. Increasing the fan to 100% will significantly increase the noise level and reduce the CPU temperature to 68 degrees Celsius which does not make any difference.