All About BTC, LTC, ETH mining as well as other alternative crypto currencies
We’ve managed to get our hands on an AMD Radeon RX 470 video card and not just any, but the best out there – the 8GB Sapphire NITRO+ AMD Radeon RX 470, so we’ve had to put it to a test to see how good it will perform for mining Ethereum (ETH) and other popular crypto currencies using different mining algorithms. The Sapphire NITRO+ 8GB model of RX 470 is probably the best you can get in terms of mining performance among other RX 470 offerings because it comes with memory clocked at 2000 MHz (8 GHz) or with other words the same memory frequency as the reference design RX 480 GPUs.
This faster video memory makes it interesting especially for mining Ethereum, but there are other good points to that video card as well such as the 8-pin PCI-E power connector, the good cooling solution and the 1260 MHz boost clock of the GPU. The only drawback is that the price of the Sapphire NITRO+ AMD Radeon RX 470 8 GB should pretty much be the same as the price of 8 GB reference design RX 480s. The 4 GB models of RX 470 are apparently equipped with slower memory, so as far as Ethereum mining goes they will perform slower than the 8 GB NITRO+ version, though i other algorithms they may not be much slower.
The hashrate that the Sapphire NITRO+ AMD Radeon RX 470 8GB manages to provide out of the box for mining Ethereum is about 24.5 MHS or almost much what the reference design Radeon RX 480 manages to deliver mining ETH. Again this is because of the 8 GHz video memory used on that model from Sapphire, other RX 470 cards with 4 GB come with 7 GHz or 6.6 GHz video memory and that will for sure result in a slower hashrate for Ethereum. The Sapphire NITRO+ manages to keep just fine the GPU boosted to the maximum 1260 MHz is supports all the time, though for Ethereum mining you can lower that frequency by reducing the power limit below 100% on the Power Target as ETH does not benefit much from the higher GPU frequency and you can reduce the power usage without a hit in performance.
What we did not like much is the default fans profile that try to keep the rotations per minute at a low value maintaining a silent operation of the GPU, but with it working at higher temperature. While mining Ethereum the RX 470 wanted to keep the fans in the 30-ies as percentage or about 1300 RPM and as a result the temperature spikes above 70 degrees Celsius, so manually increasing the cooling temperature curve or setting a fixed higher percentage is a good idea to keep the GPU cooler while mining, especially if you mine coins that use more GPU intensive algorithms unlike the one used by Ethereum that is more memory dependent. Also the default power usage of the Sapphire NITRO+ can definitely use some tweaking as it seems to be slightly higher than that of a reference design RX 480
Overclocking the Sapphire NITRO+ AMD Radeon RX 470 8GB has left us a bit disappointed. We kind of expected to be able to push the 8 GHz video memory to at least 8.8 or 9 GHz like you can on most reference design RX 480. Unfortunately we ended up with up to 8.2 GHz (2050 MHz) maximum limit from AMD’s WattMan and maximum 8.4 GHz with the use of the ASUS GPU Tweak II tool. We are still somewhat short on options for overclocking tools for the new AMD RX series of GPUs, so this forced overclocking limit has left us disappointed. We are not sure if it was forced because the GDDR5 memory chips from Samsung are not capable of working at higher frequencies without problem or as a safety measure so that the RX 470 turns out slower than RX 480 even when overclocked.
The result of the limited video memory clock is important only for Ethereum mining as the result is slower maximum hashrate. At the maximum of 8.4 GHz (2100 MHz) for the video memory we were able to get just about 25.8 MHS mining Ethereum or with other words just about 1.3 MHS more than the stock clocks hashrate. We are yet to see how the 4 GB models of the RX 470 will perform with Ethereum due to their lower default video memory clocks as well as how much it will be possible to overclock them.
When the AMD Radeon RX 480 was released there was an issue with the drivers that prevented users from successfully mining many of the crypto currencies that used sgminer as the miner just crashed with an error. Since the RX 480 was actually a new architecture there was no way to just get back to older video drivers and have no trouble running sgminer, however it seems that the situation has improved significantly since then, though it is still not perfect for some algorithms and miners. Since at that time most people were using RX 480 for Ethereum mining where no problems with the miners were present that was not much of an issue, but due to various reasons a lot of people have since moved to other alternative coins. Above you can see the hashrates for many of the more popular algorithms supported by Nicehash and tested with their dedicated mining solution that bundles multiple miner programs in a single package.
You can see some benchmarks of the AMD Radeon RX 480 using the NiceHash miner here and note that quite a few of the algorithms back then reported 0 MHS hashrate. At the moment it seems that only Neoscrypt, WhirlpoolX and Blake256r14 are still problematic and are reporting 0 MHS hashrate. That is of course only for the listed algorithms supported by NiceHash and there are quite a few others as well. It is important to note that the Sapphire Nitro+ RX 470 8GB is getting pretty close in terms of performance to a stock RX 480 with 8 GB and in some cases the results are even slightly better (due to further optimizations) and in the others the performance is not behind by much. Still the presence of a little more Stream Processors in the RX 480 gives it an advantage in the more GPU intensive algorithms compared to the RX 470. Unfortunately the GPU frequency of the RX 470 cannot be pushed much higher like on the RX 480, so hoping to compensate the difference with higher OC will just not do.
Just to add information about some more algorithms, the LBRY sgminer crashes the video driver, so we could not get a result in terms of hashrate. As for the SiaCoin sgminer, it has managed to provide us with 906 MHS hashrate mining on the Siamining pool using Stratum, so there were no problems with that miner. Hopefully the issues with some miners and some algorithms not working with the new AMD RX series of GPUs will be resolved as AMD is probably already preparing the faster RX 490 for a release alter this year and it is highly likely it being an interesting solution for crypto miners as well.
There are a lot of people that use various GPUs for mining with the stock fans that the video card comes with and normally many of these fans start to have issues in just a couple of months or after a year or so. The time frame usually depends on how clean is the environment that the mining rigs are at and how well maintained are the rigs themselves. Sooner or later it is inevitable for the fans to start behaving worse than they were initially, because of the dirt they accumulate that slowly eats away the brass or bronze bushings of the non-serviceable cheap fans that most video cards use. By non-serviceable fans we mean these where you have no access to the mechanical parts of the fan when you remove the sticker of the fan. One of the most famous and widely used such fans are the ones used on Sapphire Dual-X cards, but there are others such as Gigabyte’s Windforce and so on.
The good thing is that these cheaper fans can actually be kept in good shape as well if you know how properly disassemble them to clean them on a more regular basis. Even if you have missed the point where the fans could be kept in top shape by cleaning them regularly and have instead started breaking down, there is still a chance that you can bring them back to life as long as they have not stopped completely rotating. We have prepared a guide on how you can completely disassemble a non-serviceable fan from a Sapphire 280X, clean it up and assemble it or repair it with the help of some new bearings that you are going to be using to repair the fan making it like new. Although this guide is specifically for Sapphire’s Dual-X fans, it should be pretty much the same for many other similar fans. For comparison the turbine type coolers used on most cards, although noisier, are much higher grade and more expensive fans that can last much much longer without any attention from the user.
Depending on if you just want to clean the fans or to repair them and make them more durable you may need a different set of tools. For the first you can go with just a spray can with cleaning fluid, but for proper repair and upgrade a few more tools will be required. You will need a spray with cleaning fluid to make cleaning easier, we are using TRW brake cleaner, but anything else that is not too aggressive to plastics should be fine. You can also use alcohol-based cleaner that is not under pressure to clean the parts of the fan as well, so pretty much anything will do here. You will also need a philips and a flat screwdriver, some cyanoacrylate adhesive, a small wood screw (or a larger one for plastics) and a pair of bearings with size 2x5x2.5mm in size (this is the correct size for Dual-X fans, some other fans may require different size of bearings). This is all you will need to prepare along with some patience and a few spare fans that you may initially break until you get the hang of things if you are not careful enough.
You need to detach the fans from the faceplate holding them, usually they are held by three screws each and then comes the first step in disassembling the non-serviceable fans. You need to carefully remove the top rotating part of the fan with the blades. The top part of the fan contains not only the blades, but it is also essentially the rotor part of the brushless motor while the lower part contains the stator of the brushless motor that rotates the fan. You need to separate the two parts carefully by using three or four of your fingers to push in between the two parts (some fans come of easily than others). The important thing here is not to pull the blades of the fan and they can easily break, you just need to apply enough force with your fingers in between the two parts of the fan and you will get the desired result of the two parts separating. Gigabyte’s Windforce fans for example do require more force to come off as apparently they have a stronger plastic locking ring.
Here are the two parts of the fan disassembled, this is essentially half of the hard part already done. At this point you can just use some cleaning spray to clean up the two parts of the fan, apply some grease on the steel shaft and reassemble the fans. This would be enough to extend the lifetime of the fan significantly if you do this maintenance once every few months of operation. You just need to make sure you use a pressurized cleaning fluid that will take out all of the dirt away from the lower part of the fan as it is harder to clean than the upper part. If you are doing only the cleaning part you can just push the two parts back together and everything should be fine for a couple of more months when it would be a good idea to repeat the cleaning process again.
For the people that want to repair and upgrade their fans with dual ball bearings thus extending their lifecycle significantly you will need to continue with the disassembling part. You need to use the flat screwdriver or a flat tool that you need to insert between two of the poles of the stator and gently apply pressure. Do not push too hard, if you do not feel the stator with the PCB below moving a bit, then just move to the next pole and apply some more pressure. This is needed, because the PCB with the electronics and the stator of the motor that is on top is glued to the plastic bottom part of the fan and you need to break the glue. Be very careful not to press on the thing copper wire sued for the windings as this may damage the motor, also too much pressure may break the stator away from the PCB, so you need to be extra careful here. There is just a drop of glue, so once you feel the part rotate a bit you should be able to separate the PCB with the electronics from the plastics pretty easy.
Here are the parts separated. As you can see the bottom plastic part contains the metal bushing (sleeve bearing fans) and on top of it is the plastic holder ring that locks into place the top part of the fan. The PCB and the stator of the motor show traces of some grease and dust accumulated on it. You need to remove the plastic holder ring and be careful not to loose it and under it is the metal bushing that you need to pull out and replace with the two bearings turning your cheaper sleeve bearing fan into the usually more expensive dual ball bearing fan that provides longer lifespan and reliability. As you can see when you remove the plastic holder ring there is a lot of dirt inside, this is the thing that essentially kills the fan because it eats away the bushing unevenly and destabilizes the rotating part of the fan.
You need to turn the screw inside the metal bushing with the help of a screwdriver, again be careful here, because as soon as you feel that the screw is not rotating, but instead the whole bushing is you will need to pull out the screw with the bushing attached to it. Be careful after removing the metal bushing, because under it should be a small black disc that is easy to get lost and you will need to put it back in when you clean everything up.
Clean everything well from the dust and dirt and make sure not to loose any of the small parts and then you will be ready to start assembling back things. The difference is that instead of returning the metal bushing back you will be inserting the ball bearings inside the plastic bottom of the fan.
Start by placing the small black disc inside the bottom plastic part, make sure it is seated well on the bottom before you start inserting the ball bearings. The two 2x5x2.5mm ball bearings should fit tight inside where the original metal bushing was, just push them carefully to get inside and place the plastic ring holder on top.
Apply a small drop of cyanoacrylate adhesive on the spot where the original glue was placed and quickly place the PCB with the electronics and the stator of the motor back on top of the plastic lower part. You can use the fan cables as a guiding point in order to properly orient the two parts, so that there will be no issues gluing them together properly. What you should be extra careful about while gluing the two parts is not to rotate the bottom too much as the white plastic ring can move around and while pressing the two parts together. Make sure it stays on its original position centered above the bearings as otherwise you may have to remove the two parts and try to glue them again after reseating the plastic ring.
Wait a couple of minutes for the glue to cure and you are ready to assemble back the two parts of the fan together. Just hold them parallel to each other and gently press them until you hear a click sound. This would mean that the plastic holder ring has moved to its place and has locked onto the steel shaft of the rotor (the top part of the fan). After that you can reassemble the fan on the video card and connect it to the power in order to test that everything is working properly and it should. As a result of replacing the stock metal bushing with two ball bearings you should have the fans rotating just like brand new with a little less effort and with an extended lifespan that the bearings should offer. What you have essentially done is to upgrade your cheap sleeve bearing (single metal bushing) to a higher grade dual ball bearing fan.
As a result you should have less problems with fans on your GPU mining rigs, but as we’ve already explained even if you do the simpler procedure of cleaning the stock fans every few months you should still experience much less problems on the long run. We have already cleaned, repaired and upgraded quite a few of these Dual-X, Windforce and some other similar fans with great success and are really happy with the results. You can even upgrade the cheaper sleeve bearing fans of a brand new card to dual ball bearings, and that should be possible on many video cards even without causing potential problems with the warranty of the card. The reason for this is that if properly done one would have to actually completely disassemble the fan using the procedure above or a similar one in order to find out that the stock bushing was replaced with ball bearings and that normally does not happen in service centers, maybe unless of course you send in the card with fan problems.
We have already covered the performance of the new AMD Radeon RX 480 GPUs for mining Ethereum, so it is time to see how the GPU performs with other popular algorithms. We have already mentioned that the RX 480 apparently has some issues running sgminer (at least under Windows), so we were not able to run tests with many of the currently popular algorithms, but it seems that many people missed that part. The good news is that there is now an updated version of the NiceHash Miner that apparently adds support for GTX 1070/1080 and RX 480. So we have downloaded it and ran the built in benchmark and you can see the results above as well as the fact that some algorithms still have issues apparently hence the 0 MHS results, but it is much better than before. We have noticed that the sgminer that is being packaged and used for RX 480 now has some pre-built binaries for Ellesmere (RX 480) included. So even if you are not planning on using the NiceHash Miner on Windows, you still might get the sgminer-5-4-0-general from the bin folder and use it on Radeon RX 480.
Here is a chart comparing the performance of a reference design AMD Radeon RX 480 from ASUS in the other algorithms apart from Ethereum to an Nvidia GeForce GTX 970, namely a Gigabyte WindForce OC model and a reference design Nvidia GeForce GTX 1070 from ASUS. The benchmark did not produce results for NeoScrypt, WhirlpoolX and Blake256r14 as you can see, so it seems that some algorithms may still have issues running on RX 480. Also do note that the RX 480 has been around for just a few days, so there have not been any specific optimizations for the new Polaris architecture that it uses and further performance increases might be possible. The X11 Evo algorithm is not yet supported by the sgminer for of NiceHash, so there are no results as the dedicated miner is having trouble runnign on the RX 480 on Windows (we have not yet tried Linux).
The pleasant surprises are in Blakecoin and the X-based algorithms where the result of the RX 480 beats with a bit what the GTX 970 manages to provide in terms of hashrate. Unfortunately in the others the GTX 970 turns out faster than the RX 480 for the moment and the AMD card can definitely use some improvements in algorithms such as Lyra2REv2 and Quark for example. The GTX 1070 however manages to provide a significantly higher hashrate compared to the RX 480 and with a lower power usage than the AMD card. Again the RX 480 could get some tweaks and fixes and it definitely needs some and will most likely manage to catch up to the GTX 970, but reaching the GTX 1070 is probably too much to expect.
We should not forget that the GTX 1070 is a significantly more expensive GPU than what the AMD Radeon RX 480 sells for, but still we did not expect doubled or almost doubled hashrate provided by the GTX 1070 in most algorithms. It seems that the benchmark results we get for crypto mining and the ones when using the RX 480 for gaming are pretty much the same (apart from memory intensive mining algos such as Ethereum) where the new AMD card manages to be on par or a bit faster than a GTX 970 in some of the cases.