All About BTC, LTC, ETH mining as well as other alternative crypto currencies
Nvidia has just announced a new GPU architecture called Maxwell and their first GPU to use it – GeForce GTX 750 Ti. We’ve had a card for testing and decided to give it a try and see how it will perform for Scrypt mining as normally Nvidia GPUs are not providing as much hashrate as AMD graphics cards for crypto mining. The next Maxwell architecture from Nvidia however is interesting, because it is focused on optimization for better performance per watt – something that crypto coin miners are also interested a lot in. The new GeForce GTX 750 Ti GPUs have a power consumption of just about 60W and the price range for these cards is $150 USD. When you add the fact that a GeForce GTX 750 Ti based on the Maxwell architecture without overclock makes about 265 KH/s using CUDAminer these become an interesting solution for crypto miners.
CUDAminer startup parameters for 265 KH/s:
cudaminer.exe -o stratum+tcp://eu.multipool.us:7777 -u yourworker.cuda -p password -i 0 -l T5x24 -C 1
Furthermore after overclocking the GeForce GTX 750 Ti you can get close up to 300 KH/s hashrate out of the card without problems. There is a chance if the card allows higher overclocking frequencies and higher voltage operation as well as if it has external power and you can increase the power limiter to over 100% to get even higher performance out of it. Furthermore have in mind that CUDAminer is hot yet optimized to support the new Maxwell architecture and the hashrate we are getting out of it is with the kernel for the older Kepler architecture that is used for GTX 780 cards. So there is a chance for even higher performance with a specially optimized CUDAminer for the new Maxwell architecture…
If you are really willing to squeeze every little bit of performance for mining crypto coins with your available hardware you should be aware of the fact that you can also use the most recent Intel integrated graphics cards for mining too. The latest generation of integrated Intel graphics does support OpenCL 1.2 and thus can give you some extra hashrate that is more than yo can get alone out of the CPU only. Note that the OpenCL 1.2 support is found only on 3rd and 4th Generation Intel Core Processors as well as some other more specific models that you probably will not have available in your mining rigs anyway. Older Intel Integrated Graphics may support OpenCL on the CPU only, so they are no good for mining crypto coins unfortunately. Below you can find a list of the supported integrated Intel graphics processors that can be used for OpenCL mining:
4th Generation Intel Core Processors with:
– Intel HD Graphics 4200/4400/4600/5000
– Intel Iris Graphics 5100
– Intel Iris Pro graphics 5200
3rd Generation Intel Core Processors with:
– Intel HD Graphics 4000/2500
Intel Atom Processor Z3000 Series with:
– Intel HD Graphics
Intel Celeron Processor J1000/N2000 Series and Intel Pentium Processor J2000/N3000 Series with:
– Intel HD Graphics
Intel Xeon Processor E3 Family V2/V3 with:
– Intel HD Graphics P4000
– Intel HD Graphics P4600/P4700
You can quickly and easily check if your integrated Intel GPU does come with OpenCL support or not with the help of the free tool GPU-Z if you are not sure what kind of processor or integrated graphics you may have in your systems. Be aware that the supported Intel integrated graphics processors will not be as powerful as a dedicated AMD graphics card, but they still do manage to provide a few times higher hashrate than if you are using the CPU for mining and they can add a bit more performance to your overall hashrate. So why not take advantage if you already have the hardware available…
If you are using Bitmain AntMiner U1 USB Bitcoin ASIC miners there is something important that you should be well aware of in order to get the maximum performance and ensure optimal stability on the long run for these devices. Obviously we are going to be talking about power consumption and usage of these small ASIC miners that are designed to be powered by USB. The manufacturer has rated them at 2 watt power consumption from the USB port with a hasrate of 1.6 GH/s and tha is leaving you about 0.5W headroom for overclocking before reaching the maximum power that a normal USB 2.0 port can provide you with. But we decided to check if the Bitmain rating is rally true and to see for ourselves what is the actual power consumption of the AntiMiner U1 devices. As you can see on the photo above the power usage of the U1 miner is just 0.086A at 5V or a total of 0.43 watts is what you get with the device connected to a PC, but with no mining software running.
As soon as you fire up cgminer or another compatible mining software and the AntMiner U1 starts working at 1.6 GH/s the power consumption increases significantly that what you get in idle mode. At first we’ve measured 0.385A current used or about 1.925 watts – a bit below the manufacturer’s rating, however this is the power usage while the device is still cool. Just a few minutes later since everything gets hotter (thermal images) after the AntMiner U1 starts operating and the power usage increases along with the temperature of the chips. In just about 10 minutes after starting to mine with the device the current usage increases to 0.405A or a total of 2.025W of power, something that does not seem that much higher at first, but as you start to overclock the device you will notice that the gap between a well cooled AntMiner U1 and a very hot miner increases. The problem is that the higher power consumption leads to more heat and can also result in less performance when overclocking.
Here are the results we’ve got as a power consumption of the AntMiner U1 device connected on a USB 2.0 port. Have in mind that USB 2.0 ports have a standard limit on maximum current they can provide to a connected device of 0.5A or 2.5W in total and this can lead to lower performance you can get when overclocking as you might be hitting the interface power limit and not the device’s:
1.6 GH/s – 0.405A
1.8 GH/s – 0.456A
2.0 GH/s – 0.505A
2.2 GH/s – ~~~~~~
We have moved the AntMiner U1 to a USB port to contnue with our overclocking experiments. Have in mind that USB 3.0 ports have an increased limit of the current they can supply to a device of 0.9A at 5V or 4.5W of power, so we could continue to overclock the USB ASIC further:
2.2 GH/s – 0.568A
2.4 GH/s – 0.633A
2.6 GH/s – 0.701A
2.8 GH/s – ~~~~~~
As you can see from the results above hitting 2.2 GH/s on a USB 2.0 port was not possible as we were hitting the limit of the power the interface can provide already at 2 GH/s. Moving to USB 3.0 we could squeeze up to 2.6 GH/s by increasing the operating frequency of the device and having more power available to use from the USB port. Have in mind that overclocking the device requires an adequate cooling to be provided, so you need to be prepared for that before starting to go past the “stock” 1.6 GH/s hashrate. As you can see from our results the maximum we could get was below the maximum power the USB 3.0 interface can provide, the reason for that is that for higher performance you would also have to increase the voltage that the processor of the device operates at (default 0.8V) in order for it to continue working fine at a higher frequency. This can be done by replacing two resistors on the device and the procedure is described in the AntMiner U1 manual. Have in mind though that increasing the voltage can damage the device, so do have in mind should you decide to go for a hardware modification for even higher performance. Increasing the voltage will also seriously increase the power consumption and will require even better cooling in order not to overheat the miner!