Crypto currency mining

[moltuae]

Originally Posted by ainarssems

From what I have understood AMD cards are more flexible in terms of mining different currencies and different algorithms so you have more options to switch to if some currencies became non profitable to mine but I am sure if all of the ones you can mine with nVidia cards became unprofitable somebody would make new algorithms to use them, but it seems AMD cards are a safer bet with RX480 8GB being the best at the moment.

In my experience, it's the other way around. Using NiceHash, both AMD and Nvidia cards will usually show about 8-10 compatible algorithms, however, it seems that most of the time NiceHash chooses to mine Ethereum on the AMD cards, occasionally switching to Zcash. With Nvidia cards, switching algorithms seems to occur much more frequently, with NiceHash selecting more algorithms/coins such as Lbry.

Some algorithms are predominantly more profitable than others of course and, since NiceHash only switches when another algorithm becomes more profitable, the amount of time spent mining one algorithm over another doesn't necessarily reflect the difference in profitability. However, switching occurs much more often with Nvidia cards, suggesting that they are able to mine a wider range of algorithms with good profitability:



In the above screenshot, SHA256 is my Antimer S9 and the AMD cards are almost exclusively DaggerHashimoto. Everything else appeared after getting my Nvidia 1080 Ti cards up and running.

Incidently, here's a useful link about tweaking the GTX 1070 cards, much of which is probably applicable to other Nvidia cards too:
http://www.legitreviews.com/geforce-...w-power_195451

Originally Posted by ainarssems

There are lots of different crypto currencies and I am doubtful there is enough market space for all them long term so there is a bit of risk deciding which ones you want to invest in to.

I think you're absolutely right. I do think we're seeing the dawn of something huge. I don't think you can overestimate the enormous potential for this technology and I believe the world-changing implications of all the applications (digital money being just one of them) is vast, perhaps even bigger than the internet itself. However, while I think there are a lot of cryptocurrencies destined for big things, there's probably a LOT more destined to go nowhere.

Originally Posted by ainarssems

also tried to mine Ether directly it turns out you need at least 3GB GPU memory so at the moment I could not even try with my GTX760 2GB while waiting for RX480 to arrive.

I'm planning to experiment with direct mining soon too, if only to reduce my reliance on NiceHash and see how they compare.

Originally Posted by ainarssems

Also looked into power supplies, if you are to run 4-6 GPU's you will need 1000- 1800W PSU depending on GPU model and quantity and those are very expensive, for me it seems to be a lot smarter to run 2x650W PSU's that will be less than £150 instead of single £300 1300W PSU. Then I looked even further and decided that it might be even better getting second hand server PSU's for GPU's. As they are made for servers they are made to run 24/7 and with reliability in mind and sometimes can be had for peanuts on ebay, only downside is that mostly they are a bit loud. You can get 750W PSU that gives over 60A on 12V line for less than £40 on BuyitNow and less on auctions.

Originally Posted by MikkiJayne

Would conventional PSUs mind being run in parallel? I guess its just DC, but its never occurred to me to try! Server PSUs obviously do as standard.

I've looked at using server PSUs and I've setup a few dual-PSU rigs. You shouldn't try to run the PSUs in parallel but you must ensure that they share a ground connection. Another issue to address is how to wake the second PSU. You'll either need a relay driven by the first PSU to connect the appropriate terminals or you'll need an adaptor like this: http://www.ebay.co.uk/itm/Dual-PSU-a...-/191568455861

I've found that approach inconsistent and unreliable though. If you get the timing of the PSUs wrong, you can cause GPUs to disconnect/reconnect while the motherboard is powered, resulting in system instability.

Because I'm building rigs for customers, I needed a more reliable and repeatable solution, using readily available parts. I've just ordered another 2 GTX 1080 Ti cards and a 1200W PSU. I'm planning to standardise on a 4 card rig, with all off-the-shelf parts. I think I've found a good way of securing the graphics cards and I'm in the process of designing a frame made from 20mm aluminium extrusion. I'll post the photos/details if all goes to plan.