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AMD Radeon R9 M295X Core Clock Throttling, Heat, and Performance

No it does not. Im very happy with that.

But, when it comes to perfomance and temps, i cant figured out why M295X is +20c hotter and only marginally better at 1440p.

I blame the vcore. Because it's not clocked higher (actually lower than M290X), so that's not the reason. TDP for M295X is 125W, M290X 100W. So that's not the reason for +20c hotter chip either!

What is? Do the math, i did and vcore it is! I rest my case.
 
RageDaddy said:
I am still keeping firmly on my theory. M295X is operating with too high vCore at the moment.

Hope i can shine here someday if they fix this and it actually is hot for that reason.

:cool:

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I did it 4 times to get it right.

Set a mark, lets say 2700 frame. Get a shot at fullscreen in 2700 framish, near the end. Do another test and when in 2700 frame, get the rpm for macs fan control or istat or what ever.

Now, you got two shots, for two different runs...but in fullscreen and rpm's are about there where they really are. Temps, frames etc are from the same test (from a fullscreen shot taken), but the final result is from another run. So, both runs are done in fullscreen from start to finnish without alt+tab desktop stuff or taking shots..

Image

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And where might be this fullscreen shot that we are all talking about? Why windows? I dont use windows. Macs fan control shows 1205rpm with 56c GPU? That's not taken in the middle of the run? So 4k resolution keeps your GPU cooler than 1440p windowed run earlier? Pretty much BS.

Screen shots after screen shots, but the one that counts is missing? I wonder why...

:)
Click to expand...

98° Under Os X at 17/18

Click for full resolution :


Windows is for a better analytics tool like afterburner, and don't look Macs Fan, is obvious that the rpm is running down after the test.
In my case I have same readings in all the software I'm using (Macs Fan, iStat, Afterburner and so on)
 







I decided to run this bench with the settings above on ultra full screen. temp got to 97c so i am quite happy with that, and if improvements come later with driver updates and even SMC updates i have a few tests to compare to, so far my rimac seems ok for heat, no complaints.


If you want gaming this is my gaming rig






no comparison in speed but rImac does ok for what it is.
 
Last edited:
carlob said:
If you run Valley fullscreen there is no way to check temperature precisely with istat. In the time needed to switch to istat and check temperature, even if you are very quick, gpu has cooled down a couple of degrees. Maybe running it windowed at full screen.
Click to expand...
CMD+Tab works ;)
 
I installed windows on an external ssd and ran the Valley benchmark with GPU-Z in background logging sensor readings to a file. Interesting results I think, have a look: GPU Core clock is not going below 784 Mhz even @105C
 

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carlob said:
I installed windows on an external ssd and ran the Valley benchmark with GPU-Z in background logging sensor readings to a file. Interesting results I think, have a look: GPU Core clock is not going below 784 Mhz even @105C
Click to expand...

And the fan was working and spinning up ? (GPU-Z fan sensor is not working with m295x) Do you have any reliable data about it or at least from what you hear (silent, noticeable, loud, very loud)

From this reading it seems that the default clock of the GPU is 784, so to keep it cool, the boost (850MHz) disengage at high temp (the system should control the fan to keep temps always below 101°C pushing the fan at maximum if needed).
I had to force the fan at minimum and to force the CPU to run at 100% load and above 90°C, with the GPU over 105° to see the GPU throttle the clock below 700.
On the other hand, with the fan at maximum speed and 100% GPU and GPU load I was unable to make the GPU run hotter than 90°C.

Could you make for me another test ? The same test but windowed and taking a look at the fan speed using Macs Fan Control, and set this software in "auto".

This would be very appreciated.
 
Astelith said:
And the fan was working and spinning up ? (GPU-Z fan sensor is not working with m295x) Do you have any reliable data about it or at least from what you hear (silent, noticeable, loud, very loud)

From this reading it seems that the default clock of the GPU is 784, so to keep it cool, the boost (850MHz) disengage at high temp (the system should control the fan to keep temps always below 101°C pushing the fan at maximum if needed).
I had to force the fan at minimum and to force the CPU to run at 100% load and above 90°C, with the GPU over 105° to see the GPU throttle the clock below 700.
On the other hand, with the fan at maximum speed and 100% GPU and GPU load I was unable to make the GPU run hotter than 90°C.

Could you make for me another test ? The same test but windowed and taking a look at the fan speed using Macs Fan Control, and set this software in "auto".

This would be very appreciated.
Click to expand...


The fan was spinning up. I'm not going to install Macs Fan Control as I don't want third party software messing with the fan.

My point was re: throttling and to summarize GPU starts to throttle the core Mhz from 100C and in the range 100-106C cuts at the most 8% of the max advertised core clock (784 vs 850).
 
You can uninstall it then, anyway, im not going to ask you something you don't want to.

The fan was at maximum ? Because if the answer is no, you should consider to use 3rd party fan control for the safety of your hardware, 100 is fine, more temp I have my doubts
 
carlob said:
I installed windows on an external ssd and ran the Valley benchmark with GPU-Z in background logging sensor readings to a file. Interesting results I think, have a look: GPU Core clock is not going below 784 Mhz even @105C
Click to expand...

Your GPU went down to 762MHz during this 4 minute test, at a glance - a 10% throttle. I’m assuming this would be the same for anyone who isn’t manually controlling their fans, or allowing a third-party app to do so.

It took ~30-40 seconds for your GPU to throttle due to heat. THIS is the problem, at least for me.
 
Astelith said:
You can uninstall it then, anyway, im not going to ask you something you don't want to.

The fan was at maximum ? Because if the answer is no, you should consider to use 3rd party fan control for the safety of your hardware, 100 is fine, more temp I have my doubts
Click to expand...

Everyone with the R295 GPU is seeing more than 100C under heavy load.

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andy9l said:
It took ~30-40 seconds for your GPU to throttle due to heat. THIS is the problem, at least for me.
Click to expand...

Yes it is fast, on the other side you can keep it on 100% load for hours and it will not go past 106 (on my machine)
 
carlob said:
Everyone with the R295 GPU is seeing more than 100C under heavy load.
Click to expand...

There is another thread here with a poll for users to post their temp readings after running a linked test-demo for 10 minutes. Although there haven't been all that many responses, it is interesting to note that 39% of the responders indicated a GPU temp 100C or less.
 
Keep in mind that the clock is dynamical, not fixed as it used to be in the past GPU generations, so a minor up and down is normal and not considered as "throttle" which is a thermal protection, valley benchmark is not that demanding if compared to other stress test like PixMark, if you take a loot at my previous test my temp was stable at 99° for PixMark and FurMark but in PixMark was at 850 stable and FurMark was jumping up and down around 834.

Beside that, assuming the fan of Carlob is perfectly working (so able to spin up to 2700 if needed), his iMac does have a problem, the same problem as others had, and with the fan working + temp above 102° + the proof (of my iMac) of a well designed dissipation system, the only thing we can get out of all this tests and user reports is that there is a problem in the manufacturing process like less thermal paste than designed, a bad contact between GPU die and the heatsink or something wrong with the air conduct. (and a replace from Apple could fix this and let people have a good RiMac)
 
hfg said:
There is another thread here with a poll for users to post their temp readings after running a linked test-demo for 10 minutes. Although there haven't been all that many responses, it is interesting to note that 39% of the responders indicated a GPU temp 100C or less.
Click to expand...

I have read every single message of that thread, and posted a few. Many of the responders have the R290 and are not able to read (that thread is meant for the R295), many other ran the benchmark with the wrong settings (wrong resolution, no antialias etc.).

Haven't seen anybody with the R295 running 100% gpu load under 100C. The R295 Retina iMac runs hot by design is not a matter of a few faulty units, more or less the R295 are all around 103-106C under load.
 
carlob said:
I have read every single message of that thread, and posted a few. Many of the responders have the R290 and are not able to read (that thread is meant for the R295), many other ran the benchmark with the wrong settings (wrong resolution, no antialias etc.).

Haven't seen anybody with the R295 running 100% gpu load under 100C. The R295 Retina iMac runs hot by design is not a matter of a few faulty units, more or less the R295 are all around 103-106C under load.
Click to expand...

We have 25° C of difference, your iMac have a big heat problem, you should call Apple, because I got your temps with the fan @1200rpm

 
hfg said:
There is another thread here with a poll for users to post their temp readings after running a linked test-demo for 10 minutes. Although there haven't been all that many responses, it is interesting to note that 39% of the responders indicated a GPU temp 100C or less.
Click to expand...


All 39%* of whom failed to provide evidence, I would add. The heat issue is on all i7/M295X iMacs, be it by design, or fault of the design.

*Ignoring the third-party fan control nonsense.
 
carlob said:
I have read every single message of that thread, and posted a few. Many of the responders have the R290 and are not able to read (that thread is meant for the R295), many other ran the benchmark with the wrong settings (wrong resolution, no antialias etc.).

Haven't seen anybody with the R295 running 100% gpu load under 100C. The R295 Retina iMac runs hot by design is not a matter of a few faulty units, more or less the R295 are all around 103-106C under load.
Click to expand...

I ran the test with a maxed out RiMac including the R295, i7, 1TB SSD, and I saw my GPU temp ramp up to 99-100C with a fan speed of 2200rpm and no annoying noise. The temps dropped back down within about 15 seconds after exiting the test, and the fan was back to 1200rpm shortly thereafter.

Just sitting here reading the threads with Safari my GPU Die temp is 64C with a fan speed of 1198rpm. I have not seen any thermal issues since I received this computer and it was in the first production shipment to the US.

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andy9l said:
All 39%* of whom failed to provide evidence, I would add. The heat issue is on all i7/M295X iMacs, be it by design, or fault of the design.

*Ignoring the third-party fan control nonsense.
Click to expand...

After seeing photos of some of the thermal-past goop that have been posted, I suspect that my RiMac, being in the initial production run, may have been more closely supervised by Apple engineers and the application of the thermal paste may have been better (much thinner). Perhaps, as they got into full production with less supervision, the applications became sloppy, and later machines are having thermal transfer issues because of that.
 
I have leveled a druid from 0 to 100 since I got this machine, hours of flat 106C, and it didn't still explode, there is hope :)
 
andy9l said:
All 39%* of whom failed to provide evidence, I would add. The heat issue is on all i7/M295X iMacs, be it by design, or fault of the design.

*Ignoring the third-party fan control nonsense.
Click to expand...

In Os X there's no need of fan control (Like in Windows), and of course, with or without, nothings change.

But until I see the same screenshot with 2700rpm fan speed and 105° C all of you looks like a troll to me :rolleyes:

Come on, prove me wrong ! :)

 
I did post some of my theories several pages back.
I think you're quite on the wrong track here. All of you try to argue that 106 degrees is too many for the gpu to operate safely. I'm sorry, Lads, but I have been using two NVidia 680i SLI mainboards (exactly like that one: http://www.nvidia.com/object/designed_by_nvidia_680i_sli.html ). I'm still using one. The thing is, it's northbrigde runs at 105 degrees constantly (since new). On that basis, nobody is going to convince me that 105 degrees will kill a well-designed chip in a five year period. It's already been seven long years and despite your theories, both of the mainboards are still functioning!

So you're missing the point here. The problem is not heat. It may be 105 degrees and I couldn't care less AS LONG AS a) it's not throttling and b) it's quiet. And the chip is neither. These are the problems.
 
Astelith said:
In Os X there's no need of fan control (Like in Windows), and of course, with or without, nothings change.

But until I see the same screenshot with 2700rpm fan speed and 105° C all of you looks like a troll to me :rolleyes:

Come on, prove me wrong ! :)
Click to expand...


Why would I troll? I am currently nearly £3k down and my 5K iMac is being chucked around in a UPS van on its way back to Apple.

You are confusing the threads. You have installed third-party fan control software. Multiple softwares I would add. You are then running the benchmark with 'full fans' or 'minimum fans'.

To my knowledge, you are the ONLY person on here to have an i7/M295X iMac that apparently doesn't go over 100C, and whose fans spin to over 2,300 on that benchmark. Just look at the evidence and you will forgive my skepticism. I want to believe you, but there's always caveats with your posts. Just make a video if you want to prove it so much? Uninstall all the third-party nonsense and just run it like everyone else.

Having the fan manually running at 2,700 is simply not the solution and is not even the discussion here. The iMac, by default, will allow the M295X graphics card to throttle due to overheating in a matter of seconds. Plain and simple. The reason for this is up for debate, but the evidence so far suggests it's a component that is simply too hot for the design of this iMac to cope with.

If you want to go and fiddle with fan control, by all means do, but it's not a solution any more than saying 'just use your iMac exclusively next to an air con unit'.

I'm not here to 'win an argument' as others have suggested. I don't care about the 980m, and I wouldn't even know what that was if I hadn't had the issues with this iMac. Fact is, I immediately noticed this iMac ran much hotter than my 2010. It was 'struggling' with tasks my 2010 used to just fly through. I narrowed it down to graphics, and just went from there.
 
Pborofski said:
I did post some of my theories several pages back.
I think you're quite on the wrong track here. All of you try to argue that 106 degrees is too many for the gpu to operate safely. I'm sorry, Lads, but I have been using two NVidia 680i SLI mainboards (exactly like that one: http://www.nvidia.com/object/designed_by_nvidia_680i_sli.html ). I'm still using one. The thing is, it's northbrigde runs at 105 degrees constantly (since new). On that basis, nobody is going to convince me that 105 degrees will kill a well-designed chip in a five year period. It's already been seven long years and despite your theories, both of the mainboards are still functioning!

So you're missing the point here. The problem is not heat. It may be 105 degrees and I couldn't care less AS LONG AS a) it's not throttling and b) it's quiet. And the chip is neither. These are the problems.
Click to expand...

The risk of killing the GPU is very low, there's the throttling preventing that, but, throttling should not be triggered with a functioning dissipation system, because of this I keep saying that there's 3 scenarios :

1. Faulty system by bad manufacturing process
2. Faulty software not controlling the fan
3. Trolls

The first two can be solved calling apple for a replacement or reinstalling the Os or with SMC reset, for the 3rd there's no hope :)
 
I'm glad people are happy with their 5k iMacs. I was a potential buyer, even went to the local Apple Store on a couple occasions to admire it's screen although not all that impressive under their lighting and what little you can do with a display model.

What is holding me back is heat vs performance (this threads original topic). 95c+ for the valley benchmark seems excessive same with fire flies html5 test to me. I'd be ok with it if the performance complimented that heat but the only thing it's doing is just getting hotter and thus noisier then the 775m, 780m and 290m with too similar of performance to warrant its cost.

I realize it's mostly games but when you goto Apples website and build a 5k iMac the graphic card choice description mentions gaming performance.

I find having to install 3rd party fan controls to make a racket to keep the GPU cool a hilarious solution for a problem that shouldn't exist.

/end rant. I just wanted to like the 5k iMac so much more. Even if this issue rarely affected me I'd still be constantly thinking about it. Mental issue I guess.
 
carlob said:
Haven't seen anybody with the R295 running 100% gpu load under 100C. The R295 Retina iMac runs hot by design is not a matter of a few faulty units, more or less the R295 are all around 103-106C under load.
Click to expand...
I have the 295, used the settings described, and never got above 99 degrees.
 
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