Archive for the ‘Mining Hardware’ Category


The Chinese company Bitmain has shown to all other competitors in the field of Bitcoin ASICs how they should do their business successfully and keep all of the clients happy and coming back. The company is still shipping very fast 180 GHS ASIC devices that are on stock and with a price getting lower and lower over time. Currently you can purchase a single 180 GHS Antiminer S1 ASIC that easily overclocks to 200 GHS for 0.998 BTC and the price even includes express shipping. Really unbeatable price for something that will arrive on your door in about a week from China and you will be able to start mining with it. We are already eager to see the company come up with the next generation of ASIC chips using 28 nm technology and offering higher performance with even better performance per watt of power consumed.

For more information about the Bitmain 180 GHS Antiminer S1 Bitcoin ASIC miners….


We have already published some interesting findings about the power usage of the new GeForce GTX 750 Ti graphics cards when used for crypto mining and recently we have built a 6-card GTX 750 Ti mining rig. We have taken some time to also measure the power usage of the individual cards as well as the total power usage of the whole system in order to give you some additional details about what you can expect in terms of power consumption from such a mining rig. We have used Gigabyte GeForce GTX 750 Ti video cards (N75TOC-2GI) that do have an external onboard PCI-E power connector and we started by measuring the total power that goes to a single video card both trough the PCI-E slot as well as through the external PCI-E power connector with the help of a watt meter that is attached directly to the power lines going to the video card (using a powered extender).


As you can see on the photo the total power used by the video card is about 31W (with the card running at +135 MHz for the GPU and + 610 MHz for the video memory). Note that this power measurement is on the 12V line from the PSU going to the video card, so it does not take into account the power efficiency of the power supply and as a result the total power used by the video card from the mains will be higher by something like 15-20% (depending on the PSU). Note that we have used a powered PCI-E extender with USB 3.0 cable for the data lanes. This extender takes all the power provided to the PCI-E slot of the video card through a 4-pin molex connector and supplies both the 12V and the 3.3V power that the card uses drawing only power from the 12V line (there is a voltage regulator to output 3.3V from the 12V input on the extender’s board). So what the wat tmeter shows is the total power going from the PSU to the video card and in the case of the Gigabyte GTX 750 Ti it was 31W. Again the total power usage from the mains will be higher as this measurement does not take into account the power efficiency when converting 220V/110V to 12V.


So what is the situation with the total power usage per GTX 750 Ti video card from the mains? The easiest way to check that is to measure using a watt meter connected between a power socket and the power supply of the computer the total power consumption of the system with 6 cards and then disconnect one card and to measure again. The difference we got using this method was about 79W, though this is not for the video card only as it also affects a bit the overall power consumption of the whole system. Also note that the measured 374 Watt for the 5-card and 453 Watts with the 6-card setup are with the video cards overclocked to +135 MHz/+610 MHz. The results we’ve got with the cards running at the stock frequency were 367W with 5-cards and 432W with 6 cards or a 65W difference per card (total power used from the mains). This difference of 14 watts between stock and overclocked frequencies brings roughly about 40 KHS more in terms of hashrate for Scrypt mining (per card). Have in mind that our power supply used had an efficiency rating of about 80-85%, so this means that 15-20% of the total power used at the mains is actually wasted in the conversion between 220V/110V and 12V.

Another interesting thing that we have noticed while testing the power usage and overclocking capabilities of the 6-card GeForce GTX 750 Ti mining rig was the total power consumption that we got for the system with the power target limit changed from the standard setting of 38.5W to the 65.5W. The watt meter showed an increase of power from the 453W with the 38.5W power target limit to 556W with the 65.5W power limit – about 100W increase with the same operating frequencies with a slight increase in performance of about 90 KHS total from the 6 cards or roughly a bit over 1W per KHS and in our opinion this is not worth the extra increase in power usage, so raising the power limit may not always be a good idea!


We’ve recently built a Scrypt mining rig consisting of four AMD Radeon R9 290 by XFX for a friend and since this was actually our first rig with Radeon R9 290 cards we’ve had some interesting findings that we decided to share with you, so if you have some of these troubles we might be able to help. Aside from the four XFX video cards we’ve used an EVGA 1300W PSU (you can see the total system power consumption of 1282W from the mains), Intel Celeron G1820 processor and AsRock H81 Pro BTC motherboard, together with 4GB and Windows 7 OS. For the video cards we have used PCI-E x1 to x16 USB 3.0 Extenders with 1 meter long cable and the cards did not have any trouble working like that. Note that the Radeon R9 290 cards are not considered to be the best option for Scrypt mining, however with R9 280X cards harder to find some people decide to go for the more easily found 290 or 290X models. But unlike with Radeon R9 280X, the R9 290/290X cards have more specifics and could cause you some extra headaches until you finally make them work as they should and provide decent hashrate without problems.


The average hashrate we got from the cards running at stock frequencies of 947 MHz GPU and 1250 MHz video memory got us about 857 KH/S per card or a total hashrate of about 3.4 MH/S. This is what is considered a fairly good results for Radeon R9 290 cards and unfortunately overclocking these cards did not help us in getting higher hashrate, not that we wanted to overclock them as they are already getting quite hot mining Scrypt cryptos. It seems that XFX’s cooling is not that great for mining crypto coins as the temperatures of the VRMs gets easily over 100 degrees Celsius and that is not that great for 24/7 mining even though they are probably rated at up to about 120 degrees C or even a bit more.

One very important thing in making the AMD Radeon R9 290 or 290X cards is how you call up the cgminer, because you need to use a high thread concurrency value that often tends to bring some issues with cgminer. In order to ensure that you can start cgminer without problems you can start by using the command lines below to call cgminer.exe from a BAT file:

timeout 1
start /realtime cgminer.exe --scrypt -o stratum+tcp:// -u yourworker.1 -p password --thread-concurrency 22516 -g 1 --lookup-gap 2 -w 512 -I 20

Note that sometimes even after calling cgminer with the above commands and save a congif file and then you run cgminer.exe directly and it loads up the config file you can still get errors. So if you want to use the config file after you start cgminer with the above commands and save them in config just remove all of the parameters from the cgminer.exe start line, but still start the miner with the BAT file!

Another very important thing regarding the use of AMD Radeon R9 290 video cards for crypto mining is that these video cards do not feature any analog video outputs, so if you plan on using the mining rig without a monitor connected to a card, then you might have trouble. And you cannot just make a dummy plug with resistors, you will need to get an HDMI to VGA or Display Port to VGA adapter to plug in in one of the available video outputs and then add resistors to the VGA output side. This is the recommend solution that can save you some trouble in making the mining rig function properly or if you want to control it remotely with TeamViewer for example. If you have a digital monitor connected and are going to be controlling and monitoring the mining rig with Radeon R9 290 cards then you don’t need to bother with digital adapters to VGA.