Bitcoin Forum

Looking to start mining rig.

Have 5 x Sapphire R9 290X Tri-X
Does Asrock H81 BTC Pro works in real life to support 5 of these GPU without any issues 24x7?

Is so what power supply & how many needed? any brand recommend?

powered/un-powered risers?

what would be the cheapest CPU recommended?
Memory needed?

Thanks

This is for Alt Coin (Lite Coin)

I have the ASROCK H81 BTC with 4X 290X Cards running so far I ran out of riser cables so I will soon be able to test adding a 5th and 6th GPU. For Power Draw between my 2 rigs with these cards I would say they average about 300-350 Watts per GPU under full load my 2 GPU rig with i7 CPU is pulling a total of 750 Watts from the wall under full load. I would say you need about 1750 Watts for the cards plus additional overhead to cover the CPU Hard Drive and MB depending on what you are using so I would suggest you go with 1 X 1300 Watt PSU's put 3 GPU's on that and 1X 1000 Watt with 2 GPU's and System Components you should have enough power to handle everything with some room. As for brand I have tried Antec, Enermax, EVGA all work well. the Antec PSU's actually have a link cable to fire up both PSU's when the motherboard turns on eliminating the need for any PSU adapter cables which is nice but they are harder to find I have 2 X 1300 Platinum units ( http://www.newegg.com/Product/Product.aspx?Item=N82E16817371064 (http://www.newegg.com/Product/Product.aspx?Item=N82E16817371064)) there back in stock again :)

For CPU I have most of my rigs running on a i3
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116947 (http://www.newegg.com/Product/Product.aspx?Item=N82E16819116947)
since its the lowest power draw of 35W not the cheapest but work well with my setup

You could also use this much cheaper but 55W
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116950 (http://www.newegg.com/Product/Product.aspx?Item=N82E16819116950)

As for RAM you need at minimum 8GB to run these cards I am going to do some further testing with 16GB to see if i can get any performance boost with my multi card rig. I have one rig with 2 290x's, i7 CPU, 8GB RAM, 1300 Watt PSU running Windows 7 I am getting 960 Kh Each

My other Rig has 4 290X, i3, 8GB RAM, 2 X 1300Watt PSU's Running Windows 8.1 and I am only getting between 820-890 kh per card when i mirror the settings from my 2 GPU rig I have one card spike up to 960Kh and all other cards drop to 770KH

I still have more tinkering to do but for now i left it this was since its the most stable and highest has rate overall cards.

I hope this helps I spent many days reading forums to get this setup. I do not have the Tri X cards so there is a chance they might draw a little more power with the 3 fans.

I know a lot of people say you need a decent amount of memory for scrypt mining but I still don't understand why. If I look in taskmgr I see cgminer taking up ~55MB. I am using two 290's. Thoughts?

Concerning power supplies XFX is a good choice. They are rebadged Seasonics but generally a little cheaper than other brands, especially after rebate.

A lot of people are clueless. I have 5x 290s per mobo with 4GB of ram, and never had an issue.  2GB of ram should be more then enough for a linux miner.  That said, the distros like bamt are messed and seem to eat RAM, but my gentoo installs have 90% free memory no matter how many cards are installed.

The Asrock BTC boards will run 5 or 6 R9 290s no problem.

I am curious on your 5 card rig what are you getting per card? Do you ahve the 290 or the 290x's? What model card?

Right now I have 3x 5 card rigs, all with R9 290 (non-X).  I get 900KH/s/card consistently (899-901KH always).  I also have a 4 card rig with Sapphire R9 290 Tri-x cards, which all get 945KH/s/card consistently except for one card that won't take the memory overclock and runs at 905KH/s.

I have multiple rigs running 2 X 290X Cards all hitting 980KH for some reason on my 4 card rig with mirrored settings I can only get 710KH per card I thought it may have had to do with the ram so I upped it to 16GB no change I suspect its an issue with the thread concurrency being different with 4 cards then it is with 2. If anyone has any insight into this I would greatly appreciate and if it helps id me happy to donate for your support ;)

With less than 3-4GB or a 32bit OS, you can run into issues  - "Error -5: Enqueueing kernel onto command queue" when attempting to start cgminer.

There are brief periods of large memory allocations and CPU for the Xorg and cgminer processes.

I saw this when I built a 6x rig and was using 2GB of RAM since its what I had laying around.  With 2GB, all sorts of issues.  With 4GB, no problem.

I agree with the new cards I had to have 8GB of RAM with 2 Cards or CGMiner would crash with the enumerating kernal error. On your Multi card Rigs are you using regular CGMiner 3.7.2?

I am running 5 count R9 290 on a single board with 2G of ram, with no.problems.  You're setup is faulty if you cannot do the same.