I want to throw my 290x's at the wall! 700kH/s :O

edited December 2013 in Hardware support

Last week I decided to jump in to the Litecoin game. I picked up a Gigabyte GA-990FXA-UD3, Sempron 145, 4GB memory & Corsair HX850. I also have 2 Gigabyte Radeon R9 290x's + 2 Sapphire Radion R2 290x's.

I installed Windows 8.1 with AMD Catalyst BETA 13.11. I configured CGMiner and cannot get more that ~700 kH/s on a 290x!!!.

My thread concurrency is set to 28600. CGMiner just stalls at a black screen if I set the thread concurrency to 32765.

I've tried with just single card and I cannot get any faster than 700kH/s and doesn't load with with thread concurrency at 32765.

I read somewhere that it may be because of the Gigabyte cards to I just got a pair of Sapphire 290x's today. I replaced the Gigabytes with the Sapphires and the speeds are only marginally better (709 & 740). I still can't get CGMiner to load at 32765.

I also have another PC with a i5 and 16GB of memory...I put the Gigabyte card in there and it still tops out at 700 and crashes at 32765.

Here is one string (I also have a 5850 in there, but I removed it to troubleshoot):

start cgminer -d 1 --scrypt -I 20 -g 1 -w 512 --thread-concurrency 28600 -o WEBSITE -u USER -p PASS

Please help!


  • I've also tried reducing Intensity, still didn't work with a higher thread concurrency.

  • I dont know if i understood it correctly. Are you trying to run 4x290x on a single 850W psu?

  • Are you running all 4 cards on a HX850? Have you tried this ? -I 20 --thread-concurrency 20480 --gpu-threads 2 . Also if you run with no parameters what KH/s are you getting. Sometimes its better to let cgminer pick parameters and work from that

  • I replaced 2 gigabyte 290x cards with 2 Sapphire cards. I cannot sustain any higher than 700kH/s. Currently there are 3 290x cards in the rig, all stuck at 700kH/s. A friend of mine uses CGMiner with the same settings as me (-d 1 --scrypt -I 20 -g 1 -w 512 --thread-concurrency 32675) and it worked for him with no problems and he averages 880 kH/s. I'm missing out on at least 300 kH/s between my 2 cards due to this optimization problem! :(

    If I try no parameters, I get a whopping 14 kH/s. :(

    When I try -I 20 --thread-concurrency 20480 --gpu-threads 2 I get tons of hardware errors, I tried reducing intensity to 16 and got less hardware errors but the speeds were around 500.


  • Did you try turning it off and on again?

  • Yes, I restart the computer after every iteration of cgminer. I literally installed 8.1, catalyst 13.11 and then ran CGminer, there's nothing that should be interfering with it, but yet it is way slower than it should be.

  • work on heat management, and get a better power supply for more than 1 card. i can barely keep 280x x2 working with an 850.

  • edited December 2013

    I'm fairly certain heat is not a problem. I have it in a crate with a fan on top, If I use afterburner, temps hover around 80*c. I had it down in the 60's when I ran the fans at 100% for a while.

    I've tried with just a single card to eliminate variables with the same result. The Corsair HX850 is a very good and under-rated power supply. Heck, it even comes with 6 PCI-E connectors. I'm not even using any adapters plus I have a Sempron 145 processor which only uses 45 watts.

  • The thing is 290x needs around 300W under full load. You want to have 4 of those in your rig. Thats 1200W under load. Even assuming that the mobo, cpu, ram and other stuff takes 50W thats 1250W. Your psu provides only 850W. Im actually surprised that your system doesnt turn off when you start cgminer.
    I dont know how you want to make money off mining when you cant do elementary math. Theres also probably another reason why you cant use higher tc, but youll probably figure it out ;]

  • I've already stated I have the same issues with just 1 card installed. No where have I said I am running 4 cards on a 850 watt power supply. I will only be running 2 Sapphire cards as I bought them to replace the Gigabyte cards because I assumed that was the problem. It wasn't. 850watt is more than enough to run a single card, and I cant get over 730ish with a single card installed.

    I have all 4 cards here presently so I have 3 of them installed and it is working with the same results as before. If I could get a single card to work properly, I'm sure I can figure it out from there.

  • im running 3 x r9 290's (watercooled).

    im running on an AX1200, its a good PSU.

    i have a killawatt, and its about 1000 even on the wall plug. 1000 watts.

    ok... not saying u have a problem but.......... ;-)

    some other things to check

    1) make sure environment variables are in there
    2) turn off crossfire.
    3) turn off pcie spread spectrum in bios (check other bios settings too!!) for stability.

    mines pretty stable now.

    i get 850k from my unlocked r9 290 flashed to a 290x
    and i get about 750k from the locked r9 290's.

    my thread concurrency is at 22xx, i 20, gpu clock 850 gpu mem 1250

    im not overclocking, but im specifying the MAGIC ratio of gpu clock to gpu mem clock (have u found yours???) do it with 1 card... experiment!!)

    so my suggestions.....

    1st turn off all the BS settings like i said above.

    then experiment with 1 card for magic gpu clock / mem clock ratio. im sure its close to what i specified above.

    after that, 3 cards should all go balls to wall at max speeds.

    i have found that thread concurrency doesnt have to be high to get good rates, i have found that the intensity will max it out.

    i have also found without watercooling that the card WILL cycle down even setting the max temp high...... and setting fan higher.

    how to run at max hash?

    u need to watercool

    try ekwb.com

    they have a cheap kit.

    all 3 cards can hook together with a EK-FC-terminal block, then just a 240 mm radiator kit.

    it works great :-)

    i have a 2.4 Mhash/sec box with 3 r9 290's in it.

    im happy with it

    about to build a 2nd clone of this one.

    what cases work? with the fat ekwb radiators?

    corsair cosmos s (the smaller one) can take 2 radiators, 1 for cpu up top, and take out hard drive bays and front load the big one in the front)

    my main case is a cosmos II full size... its huge and i have 2 radiators...


    im happy.

  • Have you tried lowering the worksize to 256?

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