5 Replies Latest reply on Mar 23, 2017 9:11 AM by jeztur2003

    Let's Talk Crossfire RX 480's

    jeztur2003

      I've been doing a lot of testing I want to share some results I see a lot of people with similar issues where both cards are not being utilized. I am not using wattman as it limits you to 1.175mv so I am using MSI afterburner. I've noticed a problem with voltage related to GPU usage and performance. This 1st set of screen shots is with afterburner stock clocks for my cars 1303 core 2000 mem +50 power and +0mv=1.150

      2017.03.23-04.45.png1.gif

      Now here is the results with nothing added except +50mv=1.200 as you can see it gained 10.5 fps and the gpu usage stayed at 100% much more often, of course with the added voltage comes higher temps.

      2017.03.23-05.00.png1.gif

      So what it seems like is even at factory clocks for my MSI RX 480 Gaming X the card is not getting enough voltage at stock 1303 core 2000 mem so lets try stock rx 480 clocks of 1266 core 2000 mem with +50 power +0mv=1.150

      2017.03.23-05.14.png1.gif

      So notice now the fps from the benchmark nearly matches the overclock of 1303 core yet this was 1266 at stock voltage and the gpu usage is really good. But maybe not perfect so we are going to try stock rx 480 1266 core 2000 mem +50 power but raise +25mv=1.175

      2017.03.23-05.33.png1.gif

      Not much difference here from the +0mv=1.150 except we're using more power I'd say usage is about the same as the last test. Lets try 1266 core 2000 mem at +50 power +100mv

       

      I couldn't complete this test due to the cards crashing. This is not a fix thread this is a discussion thread and results of my experiments. I am currently using revision 3 of the bios for the cards which there really is no details for but I've noticed the watts drawn is less so I'm going to put the 2nd revision back on the cards and will be back to post results. It definitely seems like the cards when in crossfire are just not drawing enough power to push the clocks barely at stock 1266 better yet at the 1303 they shipped with. Interestingly enough when 1 card is used separately this issue is non existent.

        • Re: Let's Talk Crossfire RX 480's
          jeztur2003

          I'd also like to add I'm on Windows 10 and have ULPS (Ultra Low Power State) Disabled and Windows Power Savings set to high performance using the latest beta drivers 17.3.3 and a FX 8370 overclocked @ 4.8Ghz

          • Re: Let's Talk Crossfire RX 480's
            jeztur2003

            OK I'm back with bios revision 2 this test was run at stock 1303 core 2000 mem +50 power +0mv=1.150 I'm going to start showing average gpu usage instead of max so we can see the effect of the dips. So with the revision 2 bios we're showing a heck of a lot more watts being pulled and already the gpu usage looks good remember this is the gpu load shown here and there will be dips because heaven switches scenes where the load goes down we just have to look at the red graph and I monitor usage in real time during the tests.

            2017.03.23-06.19.png1.gif

            For the second test I tried stock rx 480 clocks 1266 core 2000 mem +50 power +0mv=1.150 now we have better gpu usage 30w less power draw.

            2017.03.23-06.30.png1.gif

            This test still at 1266 core 2000 mem +50 power but +25mv=1.175 for some reason it only ever pulled 1.175 for a second the rest of the time it stayed around 1.150 usage was actually higher 86% but took time to grab screenshot but starting to notice more red in the graph meaning usage is getting better still needs more power argh argh argh!

            2017.03.23-06.50.png1.gif

            OK here's 1266 core 2000 mem +50 power +50mv=1.200 usage is better drawing more watts getting close to the 150w these cards are rated at but our temp is going up from the higher voltage.

            2017.03.23-07.00.png1.gif

            I'll be back after awhile with some more results I think as a consumer it's important we don't just look at fps when we invest in these products I know I myself spent over $550 on these 2 cards that shipped with clock speeds they can't even run at stock voltage we shouldn't have to tinker and monitor like this and definitely not underclock your cards what's the purpose of buying a overclocked card then? The usage is just as important as the fps and some may not think that but that is where most peoples problems lie with dips in fps  or the game freezing or crashing because the card is not being supplied what it needs to run at 100% performance.

            • Re: Let's Talk Crossfire RX 480's
              jeztur2003

              This is at 1200 core 2000 mem +50 power +75mv=1.225 got really good usage unfortunately lower fps due to the lower core clock and higher temps to boot ugh. Also just now even though it doesn't show it on gpu-z i seen the watts go over 150w on both cards quite a few times.

              2017.03.23-07.31.png1.gif

              • Re: Let's Talk Crossfire RX 480's
                jeztur2003

                Tried 1200 core 1750 mem still at +50 power +75mv=1.225 to see if memory had any effect I'd say everything looks the same...

                2017.03.23-07.42.png1.gif

                • Re: Let's Talk Crossfire RX 480's
                  jeztur2003

                  So i moved onto valley as heaven heats the card to much unfortunately a bunch of my results didn't get posted here but overclocking seems to be the solution for higher gpu usage when scaling at 1080p using crossfire I just ran valley at 1400 core 2000 mem +50 power +100mv=1.225 here's the results. The cards thermal throttled using heaven once temps reached 84 degrees it started to drop the core that's why i switched to valley as it's a shorter bench and the fps aren't as high resulting in less heat. So this is my summary and it sucks if you want good scaling with good gpu usage at 1080p in crossfire then you need to overclock and overvolt the crap out of your cards... Oh and the power consumption is through the roof i seen over 180 watts on each card so at peak 360 watts!

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