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Title: help 2 x 7970 going faster than 3 x 7970 Post by: cryptohunter on December 11, 2013, 11:06:17 PM this is weird, i have always just had 2 x 7970 hashing away at 740kh each in my rig. So now I've updated to 3 x 7970 all the same brand and model they will only hash at 640kh each ? this is using the same settings in cgminer and msi afterburner.
What is happening with that? the psu are 1250W so should be enough power easily? Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: antgrinder on December 12, 2013, 01:03:04 AM the PSU should have enough power. Try to make adjustment to your settings
Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: cryptohunter on December 12, 2013, 01:56:08 AM the PSU should have enough power. Try to make adjustment to your settings Yeah, i have tried everything, perhaps 8gig of ram is not enough for 3 cards? Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: rayfloyd on December 12, 2013, 01:17:58 PM By any chance did you buy Sapphires VApor-X 7970, if so you gotta flash the bios to go into the 750 kh/s range
Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: Desensitizer on December 13, 2013, 01:23:31 AM What are your temperatures? Could the cards possibly be throttling back automatically due to how hot they are getting as a result of the added cards? Also, did you install new drivers or any other software that might have changed hash rates with the cards?
Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: ccjk on December 13, 2013, 05:05:31 AM Try this
{ "pools" : [ { "url" : "stratum+tcp://xxxxx:3333", "user" : "xxxx", "pass" : "xxxx" }, { "url" : "stratum+tcp://xxxxx:3333", "user" : "xxxx", "pass" : "xxxxx" } ] , "intensity" : "19", "vectors" : "1", "worksize" : "256", "kernel" : "scrypt", "lookup-gap" : "2", "thread-concurrency" : "22400", "shaders" : "2048", "api-port" : "4028", "expiry" : "120", "gpu-platform" : "0", "gpu-threads" : "1", "hotplug" : "5", "log" : "5", "no-pool-disable" : true, "no-submit-stale" : true, "queue" : "1", "scan-time" : "30", "scrypt" : true, "temp-hysteresis" : "3", "shares" : "0", "kernel-path" : "/usr/local/bin" } Title: Re: help 2 x 7970 going faster than 3 x 7970 Post by: aznatama on December 13, 2013, 05:56:52 AM This is a BTC forum, but seeing that nobody can read and/or don't care... I'll respond anyways...
Make sure you're powering your cards from SEPARATE RAILS, and that you're ensuring each card has enough power (COUNT how many +12v wires are going from your PSU to your card, since each line can only carry so much load). It doesn't matter if you ahve a 1250w PSU if you're loading multiple cards on a single rail. The Seasonic 1250 has 4 rails, you should have no more than one car per rail. Also, post your settings. For LTC, you should be undervolting your GPUs so that you draw less power. I have 2x 7870's in a standard PC tower, both running very quiet, at a smooth 363 kh/s, <75C, ~1500 fan speed. Undervolting will help reduce load on all your components and reduce heat/noise as well. No effect on hash rate either. |