AMD just released the new RX570 and RX580 series of Graphics cards to refresh their year old RX470/480 product line. The new cards are basically a re-branding of the RX4xx series and expectations for mining performance were not all that great considering they are based on essentially the same architecture as their predecessor. Most people are expecting the new Vega series to offer substantial improvements, but for now we will take a look at the RX480’s replacement, the RX580. In addition I will also go over a basic BIOS Mod (modification) for the RX580 8GB GPU.
I ordered 5 MSI Armor RX580 8G cards the day they were released and now have had a couple of days to play with them and thought I would share my first impressions. This article will serve as a review of this specific model, namely the MSI RX480 8G Armor, as well as offer a broader look at modifying the GPU BIOS, also called VBIOS, of the new RX5xx series of cards to help achieve optimal performance when mining cryptocurrencies such as Ethereum and Zcash.
Once quick note, through-out this guide I may refer interchangeability between VBIOS (Video BIOS) and BIOS (Basic Input Output System), but in this instance they mean the same thing and refer to the GPU’s BIOS.
The overall look and layout of the RX580 is very similar to the RX4xx series cards, and as expected not much as changed from the basic design.The card comes in the standard MSI foam fitted packing, with an additional foam separator and a dual purpose cardboard top which contains an envelope with some stickers, installation instructions, and a driver CD,
I feel the Armor series has a slightly less robustness to it when compared with the Gaming line and the actual card feels a bit more flexible and less able to tolerate excessive physical stress than its more expensive counterpart. There also is no back-plate, which I find on the newer cards can often stiffen up the feel of the cards. These are by no means detriments, as most mining rigs will pretty much be set and forget as far as mounting the actual card, and if you are careful, as you should be anyway during installation, you should have no problems.
The MSI RX580 Armor features the 8-pin PCI-e auxiliary power connector so you will need to make sure you have plenty of 8-pin connections for multiple GPU rigs. This would give it the ability in theory to draw up to 225 watts from the system, but in practice my measurements indicated a draw closer to 150 watts even with the non-optimized (for mining) default settings.
For a bit of background, the 8-pin connector is specified to be able to deliver 150 watts of additional power to the card, while the 6-pin connector is specified to deliver an additional 75 watts. These figures are on top of the 75 watts that can be delivered through the actual PCIe slot, so in theory the maximum wattage’s would be 225W (75+150) for cards with the 8-pin connector, and 150W (75+75) for cards with the 6-pin connector. In practice the power draw is usually much less, especially that which flows through via the PCIe slot, so you will often see manufacturers opt for the 8-pin connector if there is even the slightest chance the card would exceed 150 watts.
Out of the Box
Out of the box performance as expected was less than ideal for mining. Using the AMD Crimson ReLive Edition 17.4.3 drivers for Windows 10 64-bit and Claymore’s 9.1 Ethereum Dual miner, each card was mining at roughly 25 Mhs and drawing close to 150 watts each in power. When mining Zcash with Claymore’s 12.4 Zcash miner, I was getting around 320 sols per card and the power usage shot up to around 170 watts. I guess they did need that 8-pin connector after all! These results are not going to cut it so we will need to look at what we can do to increase the hashrate and decrease the power usage.
Below you can see the GPU-z readings while I was running with the default settings. Once good thing is these MSI cards use Samsung memory, which is usually a little more flexible when it comes to overclocking the memory. You can also see the default 2000 MHz memory clock and 1366 MHz core clock, which while a higher core may be good for Zcash, it can be set much lower for Ethereum mining and this reduction will also allow us to lower the core voltage to help get the excessive power consumption under control.