Radeon R9 280X Litecoin mining and Sweet Spot for 700KHash/sec (part 2)

Radeon R9 280X Litecoin mining and Sweet Spot for 700KHash/sec (part 2)

Radeon-R9-280X-Litecoin-mining-and-Sweet-Spot-for-700KHash-part-2

If you have read part 1 of this tutorial, you should have known that i promised to share my CGMiner configurations for both MSI Radeon R9 280X and PowerColor Radeon R9 280X.

 

You can check out the tutorial on How to build your own Litecoin mining rig with Radeon R9 280X if you are interested.

 

After much tweaking, I have managed to get both the MSI and PowerColor cards to produce around 700KHash/sec. At first, the MSI was giving me problem that it kept crashing when i tried to undervolt it. Solved the MSI problem by flashing it to the latest ROM and undervolt it thereafter. I am sure the hashrate can get a little higher, but at the moment, i’m happy with the GPU temperatures and low reject ratio.

 

How to optimize MSI & PowerColor R9 280X for Litecoin mining

I have slotted in a few cards to do the testing. When you are doing actual mining, it’s not recommended to slot in cards of different models, like in my example R9 280X and 7950, as R9 280X is more optimal at gpu-threads 2 while 7950 runs better at gpu-threads 1. There are ways around it though, like running two sets of configurations for CGMiner.

Radeon-R9-280X-Litecoin-mining-and-Sweet-Spot-for-700KHash-part-2-01

Undervolting

Since the 280X is a rebranded 7970, it is possible to undervolt the cards using the VBE7 method that i have outlined in the previous tutorial: How to modify video BIOS to undervolt GPU in Linux. The MSI and PowerColor cards is completely stable at 1137mV and 1100mV respectively, so if you are using my undervolting method, simply replace the 1081mV that i have recommended for 7950 with the following:

  • MSI 1137mV
  • PowerColor 1100mV

Did i mention that i was having problem with undervolting the MSI card? You might need to flash the latest ROM on the MSI card before proceeding with undervolting. It is a fix released by MSI to address overheating and VRM temperatures. You can have a look at the tutorial here if you encounter the same problem.

 

CGMiner settings

These configurations plus undervolting results in very low temperature on the GPUs, and i expect the hashrate to go even higher with proper tweaking. But this should give you a good start with acceptable hashrate for the time being.

 

For this test, i am using BAMT version 1.1 with the latest AMD Catalyst drivers installed and CGMiner 3.7.2. You may learn more about setting up BAMT in my tutorial: Litecoin BAMT version 1.1 – Easy USB Linux mining distro.

 

-g 2 -w 256 -I 20 --lookup-gap 2 --thread-concurrency 22272 --gpu-engine 1108 --gpu-memclock 1800

-g 2 -w 256 -I 18 --lookup-gap 2 --thread-concurrency 22272 --gpu-engine 1045 --gpu-memclock 1725

 

This configuration gets me around 700KHash/sec on both the MSI and PowerColor card with a low reject ratio. I have read about others obtaining hashrate as high as 750KHash/sec on other brands and configurations, but with my limited testing, this is the result that i got without compromising stability.

 

Core clock speed of 1060MHz or 1080MHz are popular choices among R9 280X owners as a lot of people are getting good hashrates with that setting. You can always take the configuration as a base and tweak around to find the sweet spot for your card.

 

2/1 Update: Here is my updated CGMiner configuration for PowerColor card: Litecoin Mining – PowerColor Radeon R9 280X Sweet Spot for 760KHash/sec


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  • Mark Newbegin

    thanks I will try this on my powercolor cards. Thanks for the update

    • shadowin1126

      Try this with a lower intensity then slowly increase. My hashrate start decreasing once i pass the -I 18 mark. Good luck with yours.

      • Mark Newbegin

        I’m using BAMT and my settings had all sorts of extra options like shaders and stuff. Can I post that here or email it to you? and see if there are settings that I need to change. I brought my powercolor card down to 1.1v, its running way cooler now. “Thanks”. The 1725 setting on the RAM speed made my card lock up solid, and start artifact-ing all over the screen. So I bought mine way back down to 1500. and its pushing only like .55MH/s per card. I was getting at least in the .67- and bouncing into the .71 range before sometimes but then always falling again.

        I’m wondering if I have other settings setup wrong on my card.

        do you have your whole config file? you can post?

        • shadowin1126

          You can share your settings here. If the 1725MHz memory is too high for your card, you can tweak that to a lower value. But remember to adjust the clock speed as well. The most important is the ratio between clock speed and memory. Some cards just doesn’t like certain settings, so tweak around to find the sweet spot for your card. 1020MHz clock speed and 1500MHz memory would be a good base to experiment too.

          • Mark Newbegin

            nice thanks.. ill put that in and see what it does… here is mine that is steady at .64-.65 and its running on 20 right now, that’s the best hash ratio I saw with no invalids.

            “auto-fan” : true,
            “auto-gpu” : true,
            “temp-cutoff” : “84”,
            “temp-overheat” : “81”,
            “temp-target” : “77”,
            “gpu-fan” : “0-100”,
            “intensity” : “20”,
            “vectors” : “1”,
            “worksize” : “256”,
            “kernel” : “scrypt”,
            “lookup-gap” : “2”,
            “thread-concurrency” : “40960”,
            “shaders” : “2048”,
            “api-port” : “4028”,
            “expiry” : “120”,
            “gpu-dyninterval” : “7”,
            “gpu-platform” : “0”,
            “gpu-threads” : “1”,
            “gpu-engine” : “1020”,
            “gpu-memclock” : “1500”,
            “gpu-powertune” : “20”,
            “log” : “5”,
            “no-pool-disable” : true,
            “queue” : “1”,
            “scan-time” : “60”,
            “scrypt” : true,
            “shares” : “0”,
            “kernel-path” : “/usr/local/bin”

          • shadowin1126

            Looks good. You wouldn’t want a very high hashrate with a lot of invalids. Let it run and if it is stable, I would say the hashrate is decent. If you decide to do more tweaking, you can try with gpu-threads 2 and a lower thread-conncurrency. I find the 280X is a bit better with gpu-threads 2.

          • Mark Newbegin

            oops.. I did have it on 2 then I changed it for some reason, I think when I copied the built in default settings for the 7950 that was preloaded in. I’ll do some tweaking. Its at .754% reject ratio, so its doing well. Its pretty solid 640MH/s. I’m all enthused now to keep tweaking, since I have 4 of these cards, 2 in service now, 2 going in Monday.

          • shadowin1126

            Okay. Happy tweaking. I have just managed to get my hands on a HIS R9 280X. Would need to do some tweaking myself.

  • i have 1x R9 Sapphire, 2x MSI – would would you suggest?

    • derrey

      I have one rig running 4 cards (2 MSI 280x and 2 Sapphire 280x).
      You can use the cgminer.conf with different settings for each card.
      The first 2 setting/cards are Sapphire and the next 2 are MSI.

      With the following setting I get 750Kh/s for Sapphire and 740Kh/s

      “intensity” : “13,13,13,13”,
      “vectors” : “1”,
      “worksize” : “256”,
      “kernel” : “scrypt”,
      “lookup-gap” : “0”,
      “thread-concurrency” : “8192”,
      “shaders” : “0”,
      “gpu-engine” : “1000-1070,1000-1070,1000-1050,1000-1050”,
      “gpu-fan” : “0-100”,
      “gpu-memclock” : “1500,1500,0,0”,
      “gpu-memdiff” : “0”,
      “gpu-powertune” : “20”,
      “gpu-vddc” : “1.200,1.200,0.000,0.000”,
      “temp-cutoff” : “95”,
      “temp-overheat” : “85”,
      “temp-target” : “75”,
      “api-listen” : true,
      “api-mcast-port” : “4028”,
      “api-port” : “4028”,
      “expiry” : “120”,
      “gpu-dyninterval” : “7”,
      “gpu-platform” : “0”,
      “gpu-threads” : “2”,
      “hotplug” : “5”,
      “log” : “5”,
      “no-pool-disable” : true,
      “queue” : “1”,
      “scan-time” : “30”,
      “scrypt” : true,
      “temp-hysteresis” : “3”,
      “shares” : “0”,

      • shadowin1126

        Thanks for sharing. Your MSI hashrate looks good. I am getting around 730KHash/sec with the same configuration. I have just managed to boost the Sapphire to 760KHash/sec on a configuration very similar to yours except the clock speed which i set it as 1090MHz. I have updated the tutorial on Sapphire here //rumorscity.com/2014/01/03/litecoin-mining-sapphire-radeon-r9-280x-sweet-spot-for-740khashsec/

        • Guest

          have you tested the vfx3d r9 280x ? i’m setting up a 3 card rig this week and any tweaks appreciated.