Archive for the ‘Tests and Reviews’ Category

Every time you get new PCI-E risers for a new GPU mining rig you may be surprised with build varying build quality and that can affect the stability of the system you are building. Even when the quality is fine there is another common problem that the standard PCI Express risers using USB 3.0 cable printed upwards exhibit – they have the tendency to move a bit in the slot and even at times disconnect. This can cause a bad connection or even a broken one and one or more of your GPUs suddenly disappearing from the miner and you starting to wonder what happened and diagnosing the whole system to find the culprit.

Fortunately there is a simple solution available if you have a 3D printer or a friend with one that can help you print a small and simple, yet very effective PCI-E Riser Lock. The 3D model is available for free on the Thingiverse website made by a user called totembe who is accepting Vertcoin tips from happy users of his creation. The simple plastic clips that you can 3D print hold the small PCB with the PCI-E x1 connector very tight to the PCI-E slot on the motherboard, so that there is no more play and the chances to have these getting disconnected are becoming pretty slim.

The PCI-E Riser Lock take just a few minutes to print and use just about 1 gram of filament and are really useful. You can clip them on both sides of the PCI-E slots, for example if there are some components preventing you from attaching the lock on the front of the slot, then just clip it on the back, it will work. The only slots that you cannot attach these locks are the ones that come with metal shielding/strengthening as they do not have a place to attach the lock to. Also some mining motherboards with more than the usual number of PCI-E slots such as AsRock H110 Pro BTC+ will not work as the slots there are too closely spaced to each other.

Do note that the design of the 3D printable PCI-E Riser Locks is not compatible with the newer designs of the PCI-E risers that have slightly larger x1 PCI-E PCBs and angled USB connectors, but then again these do not seem to suffer from the same issue of getting disconnected as the older design with the USB cable pointing up. It is possible to modify the design of the locking adapter to also work with these relatively easy, but as we’ve said already it might be pointless to use these anyway. We are yet to see similar problems with the angled USB connector risers as with the straight up USB ones, and as you already probably guess the USB connector and cable pointing up is what is causing the problems.

For more information and to download and 3D print the PCI-e Riser Lock 3D model…

For a while now the CryptoNight algorithm used by crypto coins such as Electroneum (ETN), Monero (XMR), Sumokoin (SUMO), Karbowanec (KRB) and maybe some others have been quite profitable to be mined by AMD GPUs. That is normal since AMD GPUs are doing better than Nvidia when talking about the CryptoNight algorithm, especially the latest AMD Radeon RX Vega GPUs that are doing really great in that algorithm. Even though AMD’s latest GPUs are still not entirely problem free in terms of software support and can give you some headaches making them work for mining, when they do they work really well for CryptoNight performance wise. We have prepared a quick and easy to follow guide to help you get started and save you some trouble mining CryptoNight with Vega GPUs.

– Start by downloading and installing the Radeon Software Crimson ReLive Edition Beta for Blockchain Compute as this is the driver that probably still offers the best performance for mining CryptoNight on VEGA.

– When you install the driver you need to go through the Radeon Settings / Gaming / Global Settings and for each and every GPU in your mining rig to make sure that HBCC Memory Segment is disabled as well as if you have Crossfire enabled for a pair of GPUs to also disable it. Reboot the system and check that all of the video cards have HBCC and Crossfire disabled before continuing further.

– Each time the system starts you need to disable and re-enable all of the GPUs in your system in order to get the best mining performance, you can do it manually via the Device Manager, though there is also an automated way to do it, so that the mining can start automatically on each boot. For that you need to download the respective version of Devcon for the Windows you are using, here is an easy way to obtain the required devcon version.

– Here is how to disable all AMD RX Vega GPUs and then re-enable them with the DevCon.exe tool:
devcon.exe disable "PCI\VEN_1002&DEV_687F"
devcon.exe enable "PCI\VEN_1002&DEV_687F"

– The next step is to overclock/underclock the GPUs so that you can get the optimal performance and power usage combination, here things may vary in terms of the settings you can use from card to card. You can use AMD’s Radeon Wattman built-in tool, but it is not very convenient, so going for OverdriveNTool might make things much easier in the process of testing GPU and Memory clock settings.

– Some people set the final GPU frequency/voltage settings in the registry after they finish with the test what works best, so that they are loaded automatically on boot. We however prefer to use the profile feature of the OverdriveNTool and load and apply the settings from a profile before starting the miner. Here is an example how you can load a profile you save as “XMR” for 6 GPUs using the OverdriveNTool, this way you can easily have different profiles for different algorithms:
OverdriveNTool.exe -p0"XMR" -p1"XMR" -p2"XMR" -p3"XMR" -p4"XMR" -p5"XMR"

– Now you can go for the CryptoNight miner software, there are number of these, but not all of them give you the best performance on Radeon RX Vega GPUs. The two choices for best performance at the moment are Cast XMR and the latest version of XMR-stak. If using XMR-stak just make sure you configure the miner with two threads per GPU, this would require more virtual memory. Both miners need quite a lot of virtual memory, so make sure you have something like 48-64 GB to be on the safe side and problem free.

Following the tips above you should be able to get 1800-2000 H/s for mining CryptoNight on a single AMD Radeon RX Vega GPU, depending on your GPU and memory settings, so the performance is quite good if you are able to keep the video cards cool enough. If using the XMR-stak miner you can also mine some coins using the CryptoNight-light such as AEON, the settings are the same, this algorithm just produces about double the normal CryptoNight hashrate.

We have recently talked about how you can Fix problematic fans of Gigabyte Windforce VGAs as the company tends to use cheaper sleeve bearing fans that are more prone to failure when used for GPU mining rigs. Interestingly enough Gigabyte does seem to use multiple suppliers for their Windforce fans and even though on the top the blades of the fans are the same, inside there could be interesting differences. So far most of the RX 400/500 series of GPUs from Gigabyte with Windforce fans that we’ve seen used 2x5x5.5mm metal bushings inside and as we have already mentioned these are easily replaced with readily available ball bearings and you can upgrade your fans to be more durable long term. It is a well known facts that sleeve bearings are much less resistant to higher temperatures and dust than ball bearing fans and as the operating conditions worsen their life span drops significantly.

It seems however that Gigabyte has Windforce fans with larger and not so standard metal bushings as well that cannot be directly replaced with ball bearings as their size is just not as standard. We have stumbled on some Everflow T129215SU fans used on Gigabyte Windforce fans that used 2x8x5mm metal bushings and there are simply no standard bearings that you can use with so small inside hole and so big outer diameter available. So fixing or upgrading these becomes a bit more trickier and you need to either do your own bushings with the right size to replace or use spacers so that you can fit 2×5 size ball bearings inside. We have actually done both of these already and have tried them, but not on Gigabyte Windforce. To our surprise Asus and their STRIX GPU fans turned out to be using crappy sleeve bearing fans instead of better quality and more durable ball bearing fans. The STRIX fans use the same size metal bushing as we’ve discovered in this particular Gigabyte Windforce fans, but we are going to get back with more details about that very soon…