Archive for the ‘Mining Hardware’ Category

Impressions from the Newer 5-chip Gridseed Scrypt ASIC Devices

12, Mar 2014

gridseed-5-chip-asic-new-version

In our article about our first impressions from the Gridseed 5-chip Scrypt Asic earlier this month we were not very happy with our initial experience from the device. It seems we’ve got one of the earlier builds that were not very well built and the software for using them was also at a very early stage. Today however things look much better, we just got a new unit that we have ordered and it is much better built and uses the STM32 Virtual COM port driver instead of the CP2102 USB to UART Bridge Controller that our previous unit had.

cgminer-gridseed-stm32

We have tested the new ASIC device and it works just fine with the STM32 drivers installed with the modified for low power usage cpuminer for Scrypt mining by giving the virtual COM port number of the device. The ASIC also worked just fine when we have replaced the STM32 vitual cOM Port driver with WinUSB using Zadig to use cgminer 3.7.2 for Scrypt mining on the ASIC. We still haven’t tried using the new 5-chip Gridseed ASIC device to work in dual mining mode with TLC and BTC mining running at the same time as apparently the dual mining method that have already described for our older ASIC using the CP2102 USB to UART Bridge Controller is not working for devices with STM32 Virtual COM port drivers, so we’ll be getting back with more details on that later on when we figure it out.

For the moment however we are much more satisfied with the newer revisions of the 5-chip Gridseed LTC/BTC ASIC devices, especially when we take into account the improvement of the software support side for them in the last few days.

Bitmain Selling the 180 GHS Antiminer S1 BTC ASIC for less than 1 BTC

11, Mar 2014

bitmaintech-antminer-s1-asic

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….

The Power Consumption of a 6-card Mining Rig using GeForce GTX 750 Ti GPUs

10, Mar 2014

six-gpu-rig-gigabyte-geforce-gtx-750-ti

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).

gtx-750-ti-power-usage-pci-e-power

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.

gtx-750-ti-power-usage-5-6-cards

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!


top