All About BTC, LTC, ETH mining as well as other alternative crypto currencies
We got a tip from a reader that a new dual mining mode ASIC device based on Gridseed chips might be coming out soon. The device is supposedly capable of providing up to 19.2 MHS Scrypt and 520GHS SHA-256 is listed for with a price of $12888 USD on a Chinese online store and is being sold by a company called EastShore Trade. This is a pre-order and they claim the miner will be available “at the end of March”. The photo above of the actual miner does look Ok, though the photo itself and the claimed specifications do rise some doubts, so you should treat this information with caution for the moment!
This miner is apparently composed of 4 blades (only one blade shown on the photo or all 4 blades together?), each blade can mine at a speed of 130 GH/s for SHA-256 mining and 4.8 MH/s for Scrypt mining. So, the miner can mining at a speed of 520 GH/s for SHA256 mining and 19.2 MH/s for Scrypt mining in total. The total power consumption claimed is just 800W for the four blades and the power supply is apparently a part of the miner according to the information. The miner on the photo does remind us a lot in terms of design to the AntMiner S1 and the device apparently also comes with a LAN port, so it would be independent of a computer.
19.2 MH/s worth of Scrypt mining hashrate is achievable by using a total of 64×5 Gridchip GC3355 processors or a total of 320 chips providing 300 KHS each. With the total power usage of a non-overclocked 5-chip ASIC of about 5W we should be getting about 320W for Scrypt only mining mode if the calculation is correct. The problem comes with the SHA-256 mining part, with a 5-chip solutions needing roughly about 50W in BTC mining mode this would result in 3200W power consumption for the SHA-256 mining only or a total of 3500W without overclock for Dual Mining mode. So how come we see claimed 800W for the device, this could neither be the Scrypt only power usage, neither a single blade one (4 blades shod total in 3200W). And integrating a 3200W or 3500W power supply in a miner so small does not seem very believable (again is the photo of a single blade or of the 4 blades?). So do not be in a hurry with pre-orders at least until there is more clear information about this upcoming ASIC!
If you are using the 5-chip Gridseed ASIC devices in Scrypt only mining mode you probably already know that they are using about 8W of power when overclocked. But what about optimizing the power usage even more by removing the noisy fan that might be needed for the 60W power usage in Dual mode or the 50 and something in BTC only mode, but you can go without it in Scrypt only mode. So we did just that, desoldered the fan from the ASIC and ran the device in fanless mode. And surprise, surprise the total power usage without the fan gets down to just about 5-6W overclocked to 850 MHz, but what about cooling without a fan?
Running for more than 2 hours already the ASIC in fanless mode mining Scrypt has shown that it can do just fine with passive cooling. The maximum temperature was about 36.6 degrees Celsius at the hottest point with an ambient temperature of about 25 degrees Celsius. Don’t get the wrong impression from the thermal images, these temperatures for passive cooling are more than adequate and essentially the cooling radiator is considered cool, meaning that in Scrypt only mining mode you can do just fine with passive cooling at lower ambient temperatures. If you have multiple units together you might want to have a single big fan with slow rpm just to move a bit of air around them you you can be safe even when the summer heat hits.
A word of warning though, if you remove the fan from the Gridseed 5-chip ASIC devices and for some reason you start a miner for Scrypt that does not stop the BTC mining part or you start the dual mining mode you will have trouble with cooling the device and this can lead to a damage of the ASIC caused by overheating of the chips – most likely the first to blow up would be the voltage regulators. So be careful that you run only in Scrypt mode if going fanless and to use miners that do activate only the Scrypt mining mode and disable the SHA-256 one.
Today we have decided to compare the Gridseed 5-chip BTC/LTC Dual Mode ASIC devices in terms of thermal characteristics when operating in Scrypt only mining mode (~8W overclocked) and in Scrypt/SHA-256 dual mining mode (~65W overclocked). We wanted to see how good the massive radiator and high-speed cooling fan will be able to handle in the two modes and more specifically in the dual mode as it is apparently designed to cool the device properly with the high power consumption that it has when mining for BTC (SHA-256) and LTC (Scrypt) at the same time. So we put two ASIC devices next to each other, the one on the left is running in Scrypt only mining mode and the one on the right in Dual mode mining for BTC and LTC at the same time.
We left the devices to work for an hour before taking the thermal images in order to see what are the temperatures of the two miners. Note that the top of the devices does not seem very hot and the highest temperature is that of the cooling fan’s motor. You can however see that around the device running in Dual mode the temperature is higher due to the hot air that is being blown. Looking at the bottom part of the device however we can see more serious difference in the operating temperatures of the two devices. The highest temperature of the device mining in Scrypt only mode we measured is 32.1 degrees Celsius, the device in Dual mode on the right however shows very different results – the maximum temperature we have measured was 73.5 degrees Celsius. As expected the highest temperature measured is at the part where the 3 voltage regulators are located and while they are probably rated to work at temperatures of up to 100-120 degrees C they still do get quite hot as they do not have direct contact with the cooling radiator of the device. So if you plan on running the Gridseed 5-chip BTC/LTC ASIC in Dual mode you might want to consider adding additional small radiators for problem free operation in the long run. The maximum temperature of the Dual mode ASIC aside from the voltage regulator’s region was 44 degrees Celsius, so the cooling of the Gridseed GC3355 chips is more than adequate.
What we would recommend however if you are getting Gridseed 5-chip BTC/LTC Dual Mode ASIC devices is to stick to running them in Scrypt only mining mode where their real advantage is – high performance Scrypt mining hashrate with very low power usage… and no potential problems with the cooling either. Next up we are going to desolder the fan of the Gridseed ASIC devices to see how they will be handling passive cooling in Scrypt only mining mode.