Archive for the ‘Mining Hardware’ Category

dualminer-usb-scrypt-asic

This week we have finally received a DualMiner USB Scrypt ASIC based on a single Gridchip GC3355 processor that is capable of mining both BTC and LTC or only LTC (SHA-256 and Scrypt), so we can share some of our first impressions already using the device for a day. The device uses a dip switch to switch between the mode active at the moment (LTC and BTC and LTC Only) and there are two virtual COM ports available – one for BTC or other SHA-256 and one for LTC or other Scrypt crypto mining (you need to install a virtual USB to COM driver from here). When you are in BTC and LTC mining mode you are supposed to get about 500 MH/s for SHA-256 (BTC) along with about 40 KH/s for Scrypt (LTC), however we are and you are also probably going to be more interested in the performance of the LTC (Scrypt) mining mode only as this way the ASIC uses less power and provides more performance and you better go with 70 KH/s LTC instead of 40 KH/s LTC and 500 MH/s BTC nowadays. One important thing is that when the device is in LTC mode only you need to use the BTC COM port (the first one) and when operating in Dual mode the first COM is for BTC and the second for LTC.

cgminer-dualminer

DualMiner USB Scrypt ASIC uses a modified version of cgminer that comes along with an extra GUI that might be more appearing to the new to mining users, however we prefer to use directly the cgminer from the console (version 3.1.1). The extra parameters you are passing to the cgminer include “–lo” for the LTC only mode (Scrypt only), “-S //./COM12” to set the COM port used by the device and “–dualminer-pll 850” to set the operating frequency of the chip. When you switch to LTC mode only the ASIC increases the voltage to 1.2V and uses 850 MHz to achieve 70 KH/s, in BTC & LTC mode apparently the voltage is 0.9V and the clock frequency is 550 MHz for 500 MH/s and 40 KH/s respectively. You can try increasing the MHz value a bit to about 900 to squeeze a bit more performance, though you should be careful as not all devices apparently can work at that frequency and you better have some sort of extra cooling.

dualminer-scryptguid-hashrate

Our tests show that when the device is used in a pool, the reported hashrate is a bit above 70 KH/s, the screenshot is from ScryptGuild with difficulty set to 16. You need to set the difficulty for the worker lower in order to get good actual performance due to the not so high hashrate of these miners. For the first 24 hours our DualMiner USB Scrypt ASIC has managed to get away with just about 0.15% HW errors running at 850 MHz with an extra fan for better cooling, s things are looking pretty good. We are going to perform some more tests and publish them here in the next few days, so stay tuned for more information abut these USB ASICs based on Gridseed’s GC3355 chips. And while we like how things are working with this low power Scrypt ASIC, we are not going to recommend the purchase of single units due to the low hashrate that each device provides and if you are going to invest in more of these USB ASICs, then you might want to check out the 5-chip Gridseed miners supposed to offer 300 MH/s per devices – these will cost you less for the same total performance. For the moment the price at which the DualMiner USB ASICs are being sold they are not that attractive choice, and we have ordered one just to play around with it. We are waiting for one of the larger 5-chip units to arrive in the next few days, so we are going to be reviewing it as well soon.

gigabyte-gtx-750-ti-crypto-mining

The Geforce GTX 750 Ti video cards based on the new Maxwell architecture from Nvidia have generated quite a lot of interest among the users mining crypto currencies thanks to their very good hashrate per watt of used power. And after we have tried a reference GTX 750 Ti board that does perform pretty well and overclocks decently to provide some extra hashrate we are now moving to trying out different non-reference design video cards based on the GTX 750 Ti. Out goal is to find the best choice for overclocking and gaining the maximum possible performance for use the GPU for mining crypto currencies. So we took a Gigabyte GTX 750 Ti (N75TOC-2GI) video card for a spin to see what we can get out of that board…

gigabyte-gtx-750-ti-stock-scrypt

The default Scrypt mining performance with CUDAminer was about 273 KHS, or slightly more than what we got with the reference card at stock frequencies of about 265 KHS. The two advantages of the Gigabyte board were the presence of an external PCI-E power connector and the much better cooling solution compared to the stock cooler. However we have found out that the TDP limit of the Gigabyte was still set at 38.5W in the video BIOS, though with the Power Target limit removal method you can get much higher limit set and avoid the Power Target functionality limiting your performance.

gigabyte-gtx-750-ti-stock-overclock

Overclocking the Gigabyte GTX 750 Ti card to +135 MHz for the GPU and +700 MHz for the video memory brought the Scrypt mining performance to about 303 KHS (the maximum stable clocks for mining), however we were hitting the TDP limit. So we have increased the TDP limit to 65.5W by modifying the video BIOS and flashing the modified version on the Gigabyte board and the result we got with the same overclocked frequencies was up to 322 KHS. Unfortunately the Gigabyte board did not allow for higher GPU frequencies that +135 MHz or to increase the GPU voltage higher than the default value. And while 322 KHS with a silent operation and 42 degrees C of the GPU is not a bad result at all, we are going to be checking out other different GTX 750 Ti boards to see if we are going to be able to get a bit more hashrate than that. So stay tuned for more updates on that…

antminer-s1-hashing-chips-sideways

Today we’ve decided to finally do a measurement to see how much power does a Bitmain AntMiner S1 Bitcoin ASIC use both at idle (not mining), at stock 180 GHS and at overclocked 200 GHS mode. We’ve been using Bitmain AntMiner S1 miner for a while now and have already shared our best settings for overclocking AntMiner S1 to 200 GHS as well as some very interesting thermal images that what gets hot and how hot actually gets on the AntMiner S1 board. We are going to be measuring the power consumption (at the power socket) with the help of a very good 80 Plus Gold certified Power Supply (Seasonic SS-400FL) that is able to deliver about 90% efficiency at maximum load. This means that the actual power usage of the ASIC miner is 10% less than what our measuring device shows and the other 10% of power are being lost during the conversion essentially in the form of heat dissipated by the PSU. What you are paying for is the actual power measured by the device we are using for the tests of the power consumption.

antminer-s1-idle-power-psu

The idle power we have measured was 75W (67.5W + 7.5W). This is the power usage that you can expect from the device as soon as you power up the AntMiner S1, it takes some time to start up and to connect to the Internet in order to get work from the pool and the power usage during that time is about 75W. Also should your ASIC miner loose connection to the Internet or the pool it is configured to mine at gets down and there is no backup or the other pools are also not available the device will consume 75W of power doing essentially nothing.

antminer-s1-power-usage-under-load

What you will be more interested in though is the power usage of the Bitmain AntMiner S1 ASIC when it is working and mining for Bitcoions. At the default frequency of 375 MHz of the Bitmain chips used in this device and a hashrate of about 180 GHs you can expect a power consumption of about 407W (366.3W + 40.7W). And if you overclock the device to 393.75 MHz as per our guide here you are going to be getting 20 GHS more hashrate at the cost of a small increase in power usage. In 200 GHS overclocked operating mode Bitmain AntMiner S1 ASIC will use about 422W (379.8W + 42.2W). So if you haven’t overclocked your Antiner S1 yet, then you should and our overclocking guide will ensure you get low HW error rate, lower power consumption and stable 200 GHS of hashing performance.


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