Help R9 270x / 7870

edited January 2014 in Hardware support

I have an XFX 270x and anything higher than intensity 13 gives hundreds of HW errors. Ive tried Miner 3.7.0 and 3.7.2 with the same result. If i use a TC higher than 8192 it won't even start. I had a 7870xt with the exact same problem.

cgminer --scrypt -o -O username.workername:pass --thread-concurrency 8192 -g 1 -w 256 -I 13

The above command is the only way it works without errors at a 350Kh/s



  • How much system RAM do you have?

    Additionally try using the command "--lookup-gap", also referred to as LG.  Start at a setting of 0, and raise it if cgminer barks, but do not go higher than 2.

    Also, not sure if it matters, but your URL should read "-o stratum+tcp://"
  • Thanks and I did see something about decreasing TC or increase LG when I try to run higher than 8192

  • I have 8Gb of system RAM

  • Excellent, let us know how using the LG parameter works out for ya.  If it's still not working see below...

    In the lines above the cgminer.exe command in your batch file copy/paste the following:

  • Just to be clear the command in my first post works well with everything I have tried. I have four computers as we are also a gmaing family.

     6970, 7850, 7790, 6770 but for the life of me I cant get the 270x to work 
    The LG parameter did not work, I will try your last suggestion when I get home.
    Also any TC above 8192 and I get the error message that I have exceeded my buffer.
    Thank you for your help so far, which one of the wallet addresses in your signature is for LTC?
  • That did the trick they are humming along at 425KH/s at I 17 TYVM dfalcon.

    The 7870/270x are much harder to tune. finding the right TC, clock rates, and intensity has been a challenge. I started by using the most common TC's but none of them were optimum.

    Also for the cost of a 270x over a 7850 I would not reccomend this card at all for mining.

  • Awesome, glad that worked out for ya!  So with the LG parameter set you can increase your TC with no problems?

    My LTC address is the one that starts with "L".
  • For what it's worth, I have a Sapphire 7870 that runs 400-415 Kh/s (intensities 18-20) with cgminer 3.7.2.  I experimented with a bunch of settings and the only thing that made a real difference without making it unstable was underclocking the GPU core to 950 (1050 is stock).  I left the memory speed at stock (1250) and ultimately did not use any manual settings of thread concurrency, lookup gap, etc.  Everything else either didn't help, caused hardware errors, or gave me system hangs.

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