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

[vagos1103gr]

add the same for me. never exceed 101

 

[ioxakoyba]

Astelith, what kind of 3rd party fan control software do yo use on riMac? Can you make any fan profiles there, for example when heat bumps up to certain level the fan goes to maximum.

If we assume that you're right and with maximum of 2700rpm fan the temps can keep under 100C, I am just curious can you provide us a link to a software that can automatically control the fan so that on idle/desktop use the fan is running low, but when the game starts and the temp rises it will bump the fan up to maximum of 2700rpm when GPU temp is high as 100C.

This would prevent throttling (if we still assume that you're right and when the fan is spinning on maximum rpm the GPU temp never exceeds 100C).

I am using headset when playing so fan noise won't bother me. But what bothers is that if I need to set fan to maximum manually with third part software before every time I am launching a game.

Currently I have Asus FanXpert which using I can make a profile on my gaming pc that bumps up the fans depending on the temps of CPU/GPU. I can control it complitely depending on the temps. Is this same possible with riMac too? What is the software?

The point is here - in case Astelith is right - is that with 3rd party software you might make fan to be controlled more aggressively (turning on maximum rpm on lower temps than on default), which possibly can prevent throttling complitely. Am I on the right track here..?

I would really like to see a screenshot too where the temps are above 100C and the fan is spinning 2700-2800rpm. Anyone?

(I also understand your point andy9l - the iMac is the last machine you should need to fiddle about with 3rd party softwares - but for me this is not a problem if it's working automatically. I am fiddling them also with my current Windows machine I am just interested if this problem could be fixed or at least easened with 3rd party fan control app. Is there iMac supported versions for both OS X and Windows available?

 

[andy9l]

(I also understand your point andy9l - the iMac is the last machine you should need to fiddle about with 3rd party softwares - but for me this is not a problem if it's working automatically. I am fiddling them also with my current Windows machine I am just interested if this problem could be fixed or at least easened with 3rd party fan control app. Is there iMac supported versions for both OS X and Windows available?

Absolutely - and that's great that it would work for you! What grinds my gears is others saying it's a "faulty SMC", or "faulty software". It's quite simply not. As far as I've seen, the fans spin to 2,300 every time, for everyone.

Sure, you can manually override the fans and I'm sure it'll help - but, really, this is not viable a solution. A computer of this value and power should not need to run its fans full-tilt 30 seconds into a fairly typical benchmark at half the native resolution, whilst putting out a weak 17 FPS in the process.

In my opinion, at least.

 

[Astelith]

Guys, I think you are missing some parts.

I'm doing also other more tests by my own to understand better this GPU so I'll try to summarize, and going back there's all the proof of what I'm stating here :

- In Os X there's NO NEED of 3rd party software
- In Windows you may need to install one
- 3rd party software fan control in "auto" = no 3rd party = Apple default
- My tests, where not precisely specified*, are done in "auto", so Apple default, I need them to monitor the Rpm value of the fan and understand the behavior
- The fan spin up point is 96°C, until this Temp the rpm of the fan are 1200
- The target Max Temp is 100°C
- To keep the GPU at 100°C the fan start at 96°C from 1200 to Max Speed (2700rpm)
- From a moderate demanding game to the most intense stress test I never seen the fan going above 2300rpm
- A healthy iMac never go beyond 101°C, if it happens = FAULT SW/HW -> Call Apple and ask a repair, don't send back your new toy
- Using a 3rd party fan software to manual set* the fan to 2700rpm (Max speed) and pushing to the limit the CPU and GPU together at 100%, the maximum temp recorded was 85°C for the GPU and 98°C for the CPU
- Considering this test we can consider the global thermal system of the Retina iMac very effective
- The default GPU core speed is 784MHz
- The Boost can push the core speed to 850 in a sort of random up &down (but I still don't understand when and why precisely, and is not related to the temp)
- After reaching 106°C the system activate the GPU throttling and the core drop below 700

Last but not least :

- I enjoy to test hardware and even if my unit is perfectly working I would like to understand why a lot of people are complaining
- I'm trying to help spending (wasting?) a lot of time, try at least to be constructive and if possible also to provide some screenshot of tests, they help understand and they give you credibility, rare value in this thread.

 

[SpottieOttie]

Is there any chance they'd redesign or update the retina iMac with new parts to help with this heat issues anytime soon, or will it be on the normal refresh timeline.

 

[cynics]

Is there any chance they'd redesign or update the retina iMac with new parts to help with this heat issues anytime soon, or will it be on the normal refresh timeline.

Assuming you are happy with the performance, noise is the only issue. And for something like this if its addressed it will be done so with the next riMac.

Thats not saying Apple won't release it sooner then we'd expect though. Apple has done it before with their hardware. Oddly my example is strikingly similar. The iPad 3 has a screen with hardware that is questionably powerful to power it. iPad 4 was released 7 1/2 months later.

 

[Khendal]

Guys, I think you are missing some parts.

I'm doing also other more tests by my own to understand better this GPU so I'll try to summarize, and going back there's all the proof of what I'm stating here :

- In Os X there's NO NEED of 3rd party software
- In Windows you may need to install one
- 3rd party software fan control in "auto" = no 3rd party = Apple default
- My tests, where not precisely specified*, are done in "auto", so Apple default, I need them to monitor the Rpm value of the fan and understand the behavior
- The fan spin up point is 96°C, until this Temp the rpm of the fan are 1200
- The target Max Temp is 100°C
- To keep the GPU at 100°C the fan start at 96°C from 1200 to Max Speed (2700rpm)
- From a moderate demanding game to the most intense stress test I never seen the fan going above 2300rpm
- A healthy iMac never go beyond 101°C, if it happens = FAULT SW/HW -> Call Apple and ask a repair, don't send back your new toy
- Using a 3rd party fan software to manual set* the fan to 2700rpm (Max speed) and pushing to the limit the CPU and GPU together at 100%, the maximum temp recorded was 85°C for the GPU and 98°C for the CPU
- Considering this test we can consider the global thermal system of the Retina iMac very effective
- The default GPU core speed is 784MHz
- The Boost can push the core speed to 850 in a sort of random up &down (but I still don't understand when and why precisely, and is not related to the temp)
- After reaching 106°C the system activate the GPU throttling and the core drop below 700

Last but not least :

- I enjoy to test hardware and even if my unit is perfectly working I would like to understand why a lot of people are complaining
- I'm trying to help spending (wasting?) a lot of time, try at least to be constructive and if possible also to provide some screenshot of tests, they help understand and they give you credibility, rare value in this thread.

Mine is exactly like this... 98-99-100-99-98-99-100 and so on.

 

[Astelith]

I suggest everybody looking to know how the this GPU works to read this white paper :

https://www.amd.com/Documents/PowerTune_whitepaper_WEB.pdf

You can skip page 1 and 2, the interesting things are @ 3 and 4.

In short, Temperature does not affect performance, TDP does.
Of course, if the thermal system is working and able to dissipate the TDP request of the GPU, so only a fan malfunctioning or a GPU die/heatsink bad contact can lead to throttling and severe loss of performance.

In a couple of consideration in my previous tests I was wrong thinking that tests pushing the GPU to 850 was heavy, actually the lower is the clock at 100% load the heavier is the application and the usage of all the component of the GPU, interesting...

 

[cynics]

I suggest everybody looking to know how the this GPU works to read this white paper :

https://www.amd.com/Documents/PowerTune_whitepaper_WEB.pdf

You can skip page 1 and 2, the interesting things are @ 3 and 4.

In short, Temperature does not affect performance, TDP does.
Of course, if the thermal system is working and able to dissipate the TDP request of the GPU, so only a fan malfunctioning or a GPU die/heatsink bad contact can lead to throttling and severe loss of performance.

In a couple of consideration in my previous tests I was wrong thinking that tests pushing the GPU to 850 was heavy, actually the lower is the clock at 100% load the heavier is the application and the usage of all the component of the GPU, interesting...

I think the issue on a lot of people's minds is the overall design.

For example if I built a PC with identical specs and got the same results (95c+) obviously I'd check for a fan malfunction or heat sink not installed properly.

However just like everyone that's ever built a PC knows 99 out of 100 chance it's your design causing poor ventilation be it from not enough air movement, graphic card poorly located, dead spot in airflow, etc. So you'd rethink and inevitably redesign it.

And I'm talking 95c never mind 100c+ regardless of manufacturer specs. Obviously the issue here is the overall design of an all-in-one not cooling properly (or at least not as well as some would like) you've proven that time and time again by increasing the fan manually (better ventilation) with positive results (lower temps). If you could increase it passed 2700RPM you'd have even lower temps. And if you could redesign it entirely (thicker, addition fans, liquid cooled, etc being theoretical here yes I know that's ridiculous just an example) you'd have even cooler temps then that.

 

[RageDaddy]

Then and again, why R9 M290X is +20c cooler? Only 25W less TDP and 1400-1600rpm fan?

Same chassis, same fan, same desing? Only 25W different and M295X has even lower coreclock than M290X, still +20c hotter with 2300rpm fan screaming vs 1500rpm M290X?

 

[Astelith]

I think the issue on a lot of people's minds is the overall design.

For example if I built a PC with identical specs and got the same results (95c+) obviously I'd check for a fan malfunction or heat sink not installed properly.

However just like everyone that's ever built a PC knows 99 out of 100 chance it's your design causing poor ventilation be it from not enough air movement, graphic card poorly located, dead spot in airflow, etc. So you'd rethink and inevitably redesign it.

And I'm talking 95c never mind 100c+ regardless of manufacturer specs. Obviously the issue here is the overall design of an all-in-one not cooling properly (or at least not as well as some would like) you've proven that time and time again by increasing the fan manually (better ventilation) with positive results (lower temps). If you could increase it passed 2700RPM you'd have even lower temps. And if you could redesign it entirely (thicker, addition fans, liquid cooled, etc being theoretical here yes I know that's ridiculous just an example) you'd have even cooler temps then that.

I've proven the exact opposite and even the AMD white paper confirm that the only things that matters is the TDP.
The iMac have no issue, is perfectly engineered, you can complain if you find the fan noisy but from a thermal point of view there's nothing to say !
Temps at 80° or 101° doesn't matter for this board.

 

[cynics]

I've proven the exact opposite and even the AMD white paper confirm that the only things that matters is the TDP.

The iMac have no issue, is perfectly engineered, you can complain if you find the fan noisy but from a thermal point of view there's nothing to say !

Temps at 80° or 101° doesn't matter for this board.

That completely avoided what I was talking about. I'm also on my phone at work so I haven't read that link so I have no comment on that. I'll read it when I get home.

Basically what I'm saying is I understand that is within spec but it seems excessive. You wouldn't build your own machine to operate like that. Why? That answer should apply here too.

What you are saying sounds like, my car red lines at 6500 RPM. So driving around constantly at 6000 RPM is perfectly fine. Sure it's ok but it's noisy, inefficient, and causing wear which should be unnecessary.

I honestly feel we will see a redesign in the next riMac specifically for better cooling. So then the question is was the prior (this one) design poor?

 

[Astelith]

Then and again, why R9 M290X is +20c cooler? Only 25W less TDP and 1400-1600rpm fan?

Same chassis, same fan, same desing? Only 25W different and M295X has even lower coreclock than M290X, still +20c hotter with 2300rpm fan screaming vs 1500rpm M290X?

We are speaking two different languages, and who cares about the M290X ?
The two board have a different architecture, Tonga vs Neptune, and with TDP here and in the white paper we are talking about power draw (in Watt not in C°), This board doesn't care about the C° until he reach 104-105° (so never, in a normal iMac) the performance are exactly the same as at 60°.
At 2300 the fan is not screaming and is really hard to push it to this rpm, with other 400rpm left of space, I really challenge everybody here to find a real life task that intense to put in throttle the iMac, if you can prove that I will delete my account of this forum, but you can't win

----------

That completely avoided what I was talking about. I'm also on my phone at work so I haven't read that link so I have no comment on that. I'll read it when I get home.

Basically what I'm saying is I understand that is within spec but it seems excessive. You wouldn't build your own machine to operate like that. Why? That answer should apply here too.

What you are saying sounds like, my car red lines at 6500 RPM. So driving around constantly at 6000 RPM is perfectly fine. Sure it's ok but it's noisy, inefficient, and causing wear which should be unnecessary.

I honestly feel we will see a redesign in the next riMac specifically for better cooling. So then the question is was the prior (this one) design poor?

Please, read the white paper...

 

[RageDaddy]

So you really think that a new desing, made in 28nm mobile GPU is so much different is terms of heat and raw GPU power that it explains why it heat's up in +100 celsius in seconds after GPU demanding app/software?

5870 desktop was hot, was the 6870...and how about 7870, 7970, 290X? They all gain way more GPU power, but heat and TDP didn't. Because of the 28nm process vs 40 (5870) or even 55nm (4870)? But for some reason M295X is the opposite? It's ok to run 106c in 3000€ computer? I think there is something wrong here, i really do and they will fix it. 92-95c is ok for 295X, not 102-105c.

 

[RageDaddy]

Compare M295X to smilar Nvidia 980M in a laptop! Both 125W TDP? 980M has a fan in this review, but still...

You still think, that 105c is normal for high end mobile GPU in 2015?

http://www.anandtech.com/show/8694/msi-gt72-dominator-pro-review/7

 

[Vapor matt]

Compare M295X to smilar Nvidia 980M in a laptop! Both 125W TDP? 980M has a fan in this review, but still...

Image

You still think, that 105c is normal for high end mobile GPU in 2015?

http://www.anandtech.com/show/8694/msi-gt72-dominator-pro-review/7

Thats a dedicated gaming laptop designed for mobile gaming, what is needed is an AMD gaming laptop with the 295x at its heart before you can compare temps. hardly fair to compare the 980m to the 295x


the rImac isn't sold as a gaming machine at all, and everyone knows the 980m runs cooler, so before you compare apples to oranges the best comparison would be a gaming laptop with the 295x then we shall see if the rImac has a bad cooling solution or not and what temps the 295x runs at in another machine.

the 980m wasn't even available when the rImac was in R&D so wast of time comparing temps to a chip the rImac isn't even useing.

 

[cynics]

Thats a dedicated gaming laptop designed for mobile gaming, what is needed is an AMD gaming laptop with the 295x at its heart before you can compare temps. hardly fair to compare the 980m to the 295x





the rImac isn't sold as a gaming machine at all, and everyone knows the 980m runs cooler, so before you compare apples to oranges the best comparison would be a gaming laptop with the 295x then we shall see if the rImac has a bad cooling solution or not and what temps the 295x runs at in another machine.



the 980m wasn't even available when the rImac was in R&D so wast of time comparing temps to a chip the rImac isn't even useing.

Apple pretty clearer advertises gaming performance when selecting which graphic you want when building an riMac on their webpage.

While you and I know an iMac isn't the best choice for gaming that doesn't mean everyone does. They shouldn't mention it if isn't sold that way.

 

[andy9l]

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

This board doesn't care about the C° until he reach 104-105° (so never, in a normal iMac) the performance are exactly the same as at 60°.

So far very, very few people have 5K iMacs that are staying below 105C. From the evidence in the other thread, of course.

There must be an awful lot of faulty units if the norm isn't 'normal'.

the rImac isn't sold as a gaming machine at all

Maybe so, but it mentions gaming performance when you are choosing your graphics card. It should be able to handle games without sounding like a jet fighter, or throttling. It costs £3000 for Pete's sake.

 

[Vapor matt]

So far very, very few people have 5K iMacs that are staying below 105C. From the evidence in the other thread, of course.

There must be an awful lot of faulty units if the norm isn't 'normal'.




Maybe so, but it mentions gaming performance when you are choosing your graphics card. It should be able to handle games without sounding like a jet fighter, or throttling. It costs £3000 for Pete's sake.

The 295x offers more video memory for sure, and yes it can game, but lets be fair anyone who is into gaming would never buy one for that purpose. I have tried it gaming and yes it can game but never at high end its a mobile GPU not a desktop GPU. mine dont get over 100c in anything i have tried on it. I think everyone would have liked the 980m in there rImac but it just wasn't available at the time.

apple are right in saying it can game, but its hardly going to be a mouth watering experience. what everyone really needs to know is how well the 295x performs with heat in a different machine to see if apple did scrape by with cooling the GPU or not. it is AMD's top mobile gaming GPU and for what it does i am ok with it in its limited gaming. 5k gaming is a long way off yet in a mobile device.

 

[thundersteele]

So you really think that a new desing, made in 28nm mobile GPU is so much different is terms of heat and raw GPU power that it explains why it heat's up in +100 celsius in seconds after GPU demanding app/software?

5870 desktop was hot, was the 6870...and how about 7870, 7970, 290X? They all gain way more GPU power, but heat and TDP didn't. Because of the 28nm process vs 40 (5870) or even 55nm (4870)? But for some reason M295X is the opposite? It's ok to run 106c in 3000€ computer? I think there is something wrong here, i really do and they will fix it. 92-95c is ok for 295X, not 102-105c.

Image

Those are desktop cards. Mobile CPUs and GPUs are designed to run at higher temperatures, to compensate the limited cooling options. The more you increase the temperature difference, the more efficient the cooling gets.

 

[andy9l]

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

The 295x offers more video memory for sure, and yes it can game, but lets be fair anyone who is into gaming would never buy one for that purpose. I have tried it gaming and yes it can game but never at high end its a mobile GPU not a desktop GPU. mine dont get over 100c in anything i have tried on it. I think everyone would have liked the 980m in there rImac but it just wasn't available at the time.

apple are right in saying it can game, but its hardly going to be a mouth watering experience. what everyone really needs to know is how well the 295x performs with heat in a different machine to see if apple did scrape by with cooling the GPU or not. it is AMD's top mobile gaming GPU and for what it does i am ok with it in its limited gaming. 5k gaming is a long way off yet in a mobile device.

Absolutely. I wasn't disagreeing with you, I was more criticising Apple's advertised use of the card/upgrade.

The benchmark scores in the other thread show the M295X offers a 5-10% performance boost over the M290X, with *significantly* more heat, and thus noise. It also costs £200 for the privilege and can be outperformed by last year's model. It's just one data point, I know, but it's not a positive one.

 

[RageDaddy]

Those are desktop cards. Mobile CPUs and GPUs are designed to run at higher temperatures, to compensate the limited cooling options. The more you increase the temperature difference, the more efficient the cooling gets.

Yes, i know that. But can you still give me a solid reason why M290X is +20c cooler than M295X?

25W TDP difference, lower coreclock, same computer?

25W, equals right around 6-9 celsius more heat, not 20c.

 

[Vapor matt]

Yes, i know that. But can you still give me a solid reason why M290X is +20c cooler than M295X?

25W TDP difference, lower coreclock, same computer?

25W, equals right around 6-9 celsius more heat, not 20c.

Perhaps the reason is immature drivers for the new core, the 290 has been around longer. I can remember when drivers made one hell of a difference in not only performance but also the temps. I would think AMD are working on the GPU drivers and maybe its firmware to improve it.

And it could be that the cooling solution from apple isn't as good as it could be for the 295x but until we see the GPU in another machine and see what temps its gets to we can only speculate at why it runs so hot. the 290 is a different core to the 295x so again its hard to compare the 2 cards back to back.

If apple bring out a new cooling solution i can see a lot of rImac's going back for updated versions. but i still think we should see the 295x in a different machine before we pass judgement on it completely. I am happy with mine, if it fails it will go back to apple simple as that.

 

[Astelith]

Why are you so scared by 100 degrees ? GPUs are not made of water, don't worry, they can't evaporate ! It's only a psychological barrier.

 

[ioxakoyba]

Andy9l:

Absolutely - and that's great that it would work for you! What grinds my gears is others saying it's a "faulty SMC", or "faulty software". It's quite simply not. As far as I've seen, the fans spin to 2,300 every time, for everyone.

Sure, you can manually override the fans and I'm sure it'll help - but, really, this is not viable a solution. A computer of this value and power should not need to run its fans full-tilt 30 seconds into a fairly typical benchmark at half the native resolution, whilst putting out a weak 17 FPS in the process.

In my opinion, at least.

I agree you with complitely. And just to make a point, I am still very hesitant to buy or not to buy this thing, just because with these flaws. However, If I am able to prevent throttling complitely by forcing fan to maximum rpm (2700-2800 rpm) on the lower temp point, like on 95 C, and keep it below 100 C, I may live with that.

It's just that I would like so much to unify all my home equipments to Apple Retina family (Iphone, Ipad, Macbook Pro retina and iMac retina), but I also want a machine I can use for Windows gaming - so this is the only reason keeping me to find a viable sollution to this dilemma, how to manage with iMac 5k.

Astelith:

- In Os X there's NO NEED of 3rd party software
- In Windows you may need to install one

How is this possible? Didn't you just showed in your benchmark tests that only way to keep temps under 100C is setting fan to maximum manually (on full load situations)?

Was it just shown in the previous posts that even opening a Youtube video on OS X the temp will instantly jump up over 100 C? (but presumably fan won't spin up to maximum of 2800 rpm?)

- 3rd party software fan control in "auto" = no 3rd party = Apple default

What the heck?! With my question I meant that is there a software with using you can make a custom fan profile?

For example I use a PC builded up myself that has Asus motherboard. In the motherboard bios there are settings how the fan is spinning on different temps (like on minimum is spinning 50% and when the CPU temp is over 60 C the fan spins 75% and over 70 C the fan kick into 100%).

There is also a Windows software called Asus Fan Xpert, which of using you can set a custom template - a certain points where fan goes higher when the certain temp is reached - see:

With this kind of software you can set a fan profile of your own. You do not need to manually switch fan to 100% before starting a game, but this software monitors the CPU temp and sets the fan speed automatically according the profile you make.

So on the previous posts you claim that the reason that iMac 5k GPU temp goes over 100 C and even above 105 C is just that fan is not spinning up to maximum until 105 C is being reached.

If I set with such software (like Asus Fan Xpert) iMac's fan to start to spin 100% speed when the 95 C is being reached, by your claim this would keep the GPU temp below 100 C and also prevent GPU throttling at all, correct?

(If I understood correctly, you speficially claimed that everybody that says that riMac GPU temp goes over 100 C when fan spins 2700 rpm are just BS's, correct?)

So if I am not interested about the sound level of riMac at all, but just interested in how to keep GPU under 100 C and keep it running on 850mhz setting fan to 2800rpm would solve this, right?

However, the question is, is there such software you can make similar fan profiles, compatible with iMac (especially on Windows, but possibly also on OS X).

And all you that are claiming that this is a Windows issue only, should know that this is a hardware issue, not software issue. The temp will go over 100 C also on OS X if pushed hard enough (if the fan is not spinning on 100% speed - assuming that by Astelith's claim this is the reason for the high temps).

- Using a 3rd party fan software to manual set* the fan to 2700rpm (Max speed) and pushing to the limit the CPU and GPU together at 100%, the maximum temp recorded was 85°C for the GPU and 98°C for the CPU

This would be a good news, however how do you explain all the previous screenshots on this thread where you can temps between 105-108 C (also on OS X). On 105C the fan should be on 2800rpm on default OS X automatic control, correct?

- Considering this test we can consider the global thermal system of the Retina iMac very effective

Sorry but this is just your opinion. Mine is that iMac's cooling system is on best barely acceptable, if not inadequate - if the comparable graphics cards can keep GPU temp on levels of ca. 80C where as iMac cooling systems let temp rise up to 100C and also above, it's just not very realistic to claim it effective (which also anybody with some PC gaming rig building experienced person would see from the previously linked iFixit teardown pictures - a single heatpipe per CPU/GPU leading to miniscule heat sink and a single tiny fan cannot be considered very effective cooling system with over 200 W TDP (i7 + m295X).

- The default GPU core speed is 784MHz

This is also your assumption based on no fact. I can also claim that the default GPU core speed is and should be 850Mhz.

- The Boost can push the core speed to 850 in a sort of random up &down (but I still don't understand when and why precisely, and is not related to the temp)

I understand that if the temp keeps under 100C on all circumstances, the GPU core speed stays on 850Mhz on all circumstaces on full load. So it's not any boost speed, but the default speed that we should always have.

The core throttling is just a mechanism to protect the GPU core of melting when overheating by lowering the GPU frequenzy (thus lessening the TDP output).

If the iMac cooler cannot keep up on dissipating the heat GPU outputs on 850Mhz, then the GPU protects against this by lowering it's frequenzy.

The would not happen if the iMac cooling system would have been build effeciently, so it's not very appropriate you to claim that riMac's cooling system is an effecient one.

Why are you so scared by 100 degrees ? GPUs are not made of water, don't worry, they can't evaporate ! It's only a psychological barrier.

Silicon won't evaporate in 100C, that is correct, but it's just a fact that tin joints won't last withouth fractionin in the long run on the variations between room temp and over 100C on the long run (whatever AMD's marketing speech says).

So if you want a machine to run for a long, it's better to keep GPU maximum temp under 85 C - but at least under 100 C.