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MindCrime

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Message 66186 - Posted: 12 Feb 2017, 23:24:55 UTC
Last modified: 12 Feb 2017, 23:28:54 UTC

I noticed that my 7970 wasn't sweating like it usually does when running milkyway, I'm currently running 6 concurrently but have confirmed this behavior from 1-6. So utilization stays around 99% but core temp is a cool 66c, so I took a look at GPUshark and GPUz. I can see the clock speed bouncing up and down from 500mhz to 1000mhz, though the power-state stays at 0.

I was working on another rig and swapped the monitor from the 7970 to that one. I noticed the 7970 fan speed picked up shortly after unplugging the monitor. So when I connected the monitor back to the 7970 I checked the GPU usage and I could see full load and full clock speed and the temps climbed to 75-76c. Now that the monitor is back on it has fallen back to 66c and the clock is bouncing up and down again.

Edit: I forgot to mention the run times are drastically longer when the clock is bouncing around. Going from 270sec down to 200sec when performing like it should.

I have updated the driver to the newest but the behavior stays the same. Anyone ever experienced anything like this? The connection is DVI to DVI, maybe I should try HDMI?
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Message 66188 - Posted: 13 Feb 2017, 12:15:00 UTC - in response to Message 66186.  

I noticed that my 7970 wasn't sweating like it usually does when running milkyway, I'm currently running 6 concurrently but have confirmed this behavior from 1-6. So utilization stays around 99% but core temp is a cool 66c, so I took a look at GPUshark and GPUz. I can see the clock speed bouncing up and down from 500mhz to 1000mhz, though the power-state stays at 0.

I was working on another rig and swapped the monitor from the 7970 to that one. I noticed the 7970 fan speed picked up shortly after unplugging the monitor. So when I connected the monitor back to the 7970 I checked the GPU usage and I could see full load and full clock speed and the temps climbed to 75-76c. Now that the monitor is back on it has fallen back to 66c and the clock is bouncing up and down again.

Edit: I forgot to mention the run times are drastically longer when the clock is bouncing around. Going from 270sec down to 200sec when performing like it should.

I have updated the driver to the newest but the behavior stays the same. Anyone ever experienced anything like this? The connection is DVI to DVI, maybe I should try HDMI?


Does this happen only when the monitor is on and you are viewing it or even when it is turned off by the on/off switch on the monitor itself? It makes sense if it's trying to drive the monitor at a high resolution for it to take more gpu time away from crunching.
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Message 66189 - Posted: 13 Feb 2017, 22:55:04 UTC

Do you normaly use a dummy plug on that GPU ?
I dont know if they are still needed
this rig i inherited has got them and is stable.

apart from cooking a 7970 a month ago :(
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Message 66195 - Posted: 15 Feb 2017, 21:56:01 UTC - in response to Message 66189.  
Last modified: 15 Feb 2017, 22:00:34 UTC

So the monitor in question is a 17" 4:3 running 1280x1024. In the past I have used a dummy plug on this 7970 but currently I don't.

I got the monitor used, it has a broken power button. So I ran a test and hopefully I can attach this image and explain it.



1. Just enabled GPU in boinc, it starts warming up seems normal
2. This is how it normaly runs, I'm on forums and gmail at this time
3. I go afk, screen saver (blank screen) comes on and monitor goes to power save (yellow light)
4. I wake monitor but then unplug the power cord
5. I unplug the DVI cable

I'm going to redo this with an hdmi to dvi cable (monitor only has vga and dvi)
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Message 66196 - Posted: 15 Feb 2017, 22:48:11 UTC - in response to Message 66195.  
Last modified: 15 Feb 2017, 23:40:14 UTC

I went on to try an HDMI-DVI cable to isolate the cable or the GPU connector. I got the same behavior so I went on to look at what might be downclocking or power savings things were going on. I discovered ULPS and in Afterburner there is an option to disable it. I thought I had found it but it was just that the restart delayed the symptoms. I then plugged in another monitor, equal size and resolution. I noticed the higher temps and fan speed and the constant full core clock. But shortly afterward it slipped back into its old ways.

Pretty sure this is software level, possibly driver level but I doubt hardware. I'll run some Collatz and see how it behaves.

Edit: Seems to be running Collatz as it should. Run times, credit, heat, fan etc. I wonder if this is a driver related double precision thing.

Edit2: I read that the FGRP tasks at einstein have some double precision at the end so I thought I'd try those and see how they behave. I don't know what looks normal but near the end of every WU the gpu behaves similarly to milkyway if I were running 1 milkyway wu at once.

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Message 66197 - Posted: 16 Feb 2017, 1:27:55 UTC - in response to Message 66196.  
Last modified: 16 Feb 2017, 1:28:30 UTC

So here it is, milkyway runs slower when my monitor is connected to the gpu. The timings of the behavior seem to coincide with when the WUs started. I have 5 WUs running concurrently, if I start GPUz sensors, I can see the core voltage going up and down. I leave GPuz running, unplug monitor and about the time those WUs finish and new ones start the core voltage will hold steady at max. When I plug the monitor back in the current WUs will run at max but as new ones are started the voltage will start dropping and become erratic as all 5 slots have started new WUs with the monitor plugged in.

Milkyway also sets my gpu core at 1000mhz, while collatz and einstein use it at 1050 (default). What else is in that configuration that might be causing this?
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Message 66198 - Posted: 16 Feb 2017, 12:55:20 UTC - in response to Message 66197.  

So here it is, milkyway runs slower when my monitor is connected to the gpu. The timings of the behavior seem to coincide with when the WUs started. I have 5 WUs running concurrently, if I start GPUz sensors, I can see the core voltage going up and down. I leave GPuz running, unplug monitor and about the time those WUs finish and new ones start the core voltage will hold steady at max. When I plug the monitor back in the current WUs will run at max but as new ones are started the voltage will start dropping and become erratic as all 5 slots have started new WUs with the monitor plugged in.

Milkyway also sets my gpu core at 1000mhz, while collatz and einstein use it at 1050 (default). What else is in that configuration that might be causing this?


have you tried running less than 5 workunits at one time and see if it still happens? It is strange but I wonder it could also be that MW is just maxing out your gpu and then when you unplug the monitor it isn't fully used anymore. You would think it wouldn't be fully used when the monitor was off, or even in blank screen mode though. Can you plug the monitor into it's own strip and then just turn the power off to it and see if it does the power cycling or if the physical unplugging of it is the key to running faster.
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Message 66199 - Posted: 16 Feb 2017, 20:21:43 UTC - in response to Message 66198.  

I've tried 1-7. In my experience it scales pretty linearly, however much you add they go that much slower, except you get a little bit of a win with all the transitions of these short compounded WUs.

I believe I came up with this while trying to fall asleep last night. I'm doing some updates and such now but when I reboot later I am going to disable the 3770k's hd4000 igpu. I'm not using a split desktop or dual monitor or anything but I do have the hd4000 enabled and have used it in boinc a bit, but usually I don't use it. I don't know what exactly it does to the 7970 before or after the monitor is unplugged but I won't be surprised when turning it off in the bios rectifies this. Or better yet maybe plug the monitor into the hdmi jack on the mobo IO and see what happens. I'll try to remember to follow up with my solution.
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Message 66201 - Posted: 17 Feb 2017, 12:56:52 UTC - in response to Message 66199.  

I've tried 1-7. In my experience it scales pretty linearly, however much you add they go that much slower, except you get a little bit of a win with all the transitions of these short compounded WUs.

I believe I came up with this while trying to fall asleep last night. I'm doing some updates and such now but when I reboot later I am going to disable the 3770k's hd4000 igpu. I'm not using a split desktop or dual monitor or anything but I do have the hd4000 enabled and have used it in boinc a bit, but usually I don't use it. I don't know what exactly it does to the 7970 before or after the monitor is unplugged but I won't be surprised when turning it off in the bios rectifies this. Or better yet maybe plug the monitor into the hdmi jack on the mobo IO and see what happens. I'll try to remember to follow up with my solution.


I saw it yesterday at another project when I had an external monitor plugged in the crunching slowed to a crawl, but after I unplugged it it zipped right on thru the unit. I use vnc to log in remotely to most of my pc's but do the monitor thing sometimes. It was an AMD 6670.
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