Archive for the ‘Tests and Reviews’ Category


Normally when you run a multi-gpu mining rig you are monitoring the operating temperature of the GPU and if it is keeping an acceptable level, then you think that everything is fine and may not pay attention to other components. We have done an interesting experiment with a Gigabyte GeForce GTX 970 WF3OC-based mining rig taking thermal images of the back of one of the cards in the setup while it is mining Ethereum and while it is mining Decred. As you probably know the Dagger-Hashimoto algorithm used by Ethereum is heavier on the memory even though the total power usage is lower while Decred and the Blake-256 implementation it relies on is more power hungry and not so dependent on the memory.

The power usage of the GTX 970 while mining Ethereum is around 150 Watts while mining Decred it goes to about 175 Watts. The GPU temperature of the GTX 970 while mining Ethereum in the test mining rig is around 68 degrees Celsius while mining Decred it goes to about 75 degrees Celsius. This of course is with custom settings for the fans, because normally Nvidia wants to keep the target temperature at 80 degrees Celsius, but that might not be that great for 24/7 mining. But if you look at the back of the GPU with the help of a thermal camera you can find pretty interesting things like the fact that the backside memory chips that do not have cooling like the ones on the front of the card actually get pretty hot. A bit too hot if you ask us especially in the case with Ethereum mining with their temperature reaching about 105 degrees Celsius while the back of the card itself remains at not more than 75-80 degrees. In the case of Decred mining, even though the total power usage is higher, the memory chips remain with over 20 degrees lower temperature and the back of the card is similar in temperature, so the difference of the overall temperature is not that big.

So if you are mining Ethereum, especially if you are getting into it just now, you might want to be sure that the GPUs you are using have better cooling on all of their memory chips, including the ones on the back of the card if there are such. While there might be no issues in short term with such higher operating temperatures of the video memory chips, on the long run temperatures of over 100 degrees Celsius might cause you hardware issues and you would want to avoid these on a mining rig that needs to fun 24/7. Do note that while this experiment was performed on Nvidia-based hardware you can expect to see similar results on AMD-based video cards as well with Ethereum driving the temperatures of the video memory higher than other mining algorithms.


Looking at the official specifications of the iBeLink DM384M X11 ASIC miner state that the device should be capable of 384 MHS X11 hashrate (plus/minus 10 percent) with a power consumption of 715W measured at the wall with 25 degrees Celsius ambient temperature. This should be the numbers for the default configuration, however we did some measurements ourselves in order to get more accurate results in order to be able to do better calculations about the cost of operating the device. We have already measured on NiceHash an average hashrate that is slughtly above the official number of 384 MHS, so this is good, but what about the actual power usage and more importantly noise level. In our first impressions from the device we already mentioned that it is pretty noisy and not suitable for use in room where people will be present, but let us see what is the exact noise level as well.


The power supply built into the miner is an 850 Watts server grade one that is compatible with 100-240V range (for worldwide use). The exact model is ASPOWER U2A-A20850-D and according to the official specifications is it rated as 80 Plus Silver, so a high efficiency solution. At stock settings (110 MHz PLL) the power usage we have measured on the wall with 230V EU power input was 686 Watts as you can see on the photo, the power usage in Watts might be slightly higher in US and other 110-120V countries due to slightly lower power efficiency. Increasing the operating frequency with +1 MHz steps is resulting in the power usage going up with about 5-6W on each step, so the 850W capacity of the PSU should be able to take up some nice extra overclock if the chips are capable of working well when overclocked and cooled well. We are going to be doing more extensive testing about the overclocking potential with results on the power usage and performance changes, working temperatures and cooling very soon.


Now for the noise level, as already mentioned it is pretty high… just like from a rackmountable server for example. With a measurement showing about 72.6 dBA average it is perfect to be installed in a data center or a dedicated mining room, but it is not suitable for home miners as the noise level is too much for people to be in the same room for more than a few minutes… and even in the next room it might be quite noisy. The reason for the high level of noise is that the unit uses server grade fans by Delta Electronics and they are set to run at maximum RPM all the time (no temperature control). The same goes for the fan used in the power supply, a powerful Delta Electronics fan running at maximum RPM all the time, even though the PSU is highly efficient and there is not so much heat generated. The good thing about this default fans setup is that even at not that good conditions such as high ambient temperature the miner should be able to operate without any issues at optimum level. The not so good part is that small miners might have issues with the high level of noise and would probably want to do something to make it less noisy without compromising performance – this is possible with some modifications and we are already working on a solution to optimize the cooling, so more on that will be coming soon as well.


The iBeLink DM384M X11 ASIC miner is actually advertised as a DASH ASIC miner with DASH (previously known as DarkCoin) being the most popular and widely used X11 altcoin, is also currently rated as number 6 in terms of Market Capitalization. The ASIC miner can be used for any coin using a regular X11 algorithm for mining and in fact mining DASH with it is not the most profitable and anyone who purchases a new ASIC miner know that the first thing he needs to do is to ROI first in the fastest possible way and then can choose what to mine based on subjective preferences for example. So if you just got the 384 MHS X11 ASIC miner iBeLink DM384M you would probably want to head on to NiceHash and sell your hashrate to anyone willing to buy it as it will get you a few times more profit than directly mining for DASH at the moment according to the What to Mine service. The reason is simple, there are many new altcoins popping up all the time that use X11 algorithm and people are renting hashrate to mine them and with the increased demand for hashrate you might earn much more than mining for a more established coin such as DASH.


Here is how the average hashrate looks like when selling your X11 hashrate with the iBeLink DM384M X11 ASIC miner on NiceHash with the graph covering more than half a day. The average hashrate reported poolside is about 392 MHS with an average pay rate of about 0.5 BTC per Gigahash per Day. As mentioned earlier today you should update to cgminer 3.5.6 for the iBeLink machine in order to get the software that supports NiceHash’s extranonce in order to minimize stale shares and maximize profit. If the above trend continues for 24 hours this would mean an actual daily profit for the iBeLin X11 ASIC miner of about 0.2 BTC at the moment and that is pretty good when you are looking to get the fastest ROI time. Have in mind though that the profitability of X11 at NiceHash may vary more that if mining for any given more established X11 crypto currency with a stable exchange rate. There is always the possibility of jumping at the right time to the right new coin and making even better profit thanks to the high hashrate that the ASIC miner provides, but the risk is also higher and you may actually make less in the end this way.