i9 sucks?

mavericks7913

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It seems if you constantly work with iMac 2019 with i9-9900K, the maximum speed is 3.8ghz due to iMac's poor cooling performance. I dont have an exact data for short uses but this is very concerning result since iMac cannot use high clock speed. Few iMac 2019 from my area reported that iMac 2019 is so hot. Technically, the inner designed didnt change since 2012. I mean the cooling system. What do you expect? i9-9900K requires a high-end CPU cooler and yet iMac has a small fan to cool both CPU and GPU at once which is the worst cooling system I ever saw.

Perhaps I should wait for the next model since Apple didnt update iMac with a new design since 2012? They def need to make a whole new iMac with better cooling system or it wont be able to use all the power from CPU.
 

slayerizer

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Nov 9, 2012
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piping YES to /dev/null should not be a part of any workflow. I doubt that most person can keep the cpu to 100% on all cores for that long (besides a 3d render/big video render).

I'm sure that under a normal use the machine would never throttle. If someones does a render, why can't they wait a few more minutes?
 

mavericks7913

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Real world experience or something you found on the internet?

The iMac Pro is not having this issue. Just sayin...
I used iMac Pro for more than one year.
[doublepost=1560638857][/doublepost]
piping YES to /dev/null should not be a part of any workflow. I doubt that most person can keep the cpu to 100% on all cores for that long (besides a 3d render/big video render).

I'm sure that under a normal use the machine would never throttle. If someones does a render, why can't they wait a few more minutes?
Because Im concerning overheating issues and because of it, iMac does not perform 100%.
 

mcnallym

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Oct 28, 2008
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Pretty sure had a similar thread to this before.

5.0ghz is the turbo boost speed for a single core, not all 8.

Sustained 8 core at 3.8 is still better then the spec page 3.6 that intel state for 8 core.

Would it boost more with better cooling. Yes it would. Is it throttling below spec. No.
 

mavericks7913

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Pretty sure had a similar thread to this before.

5.0ghz is the turbo boost speed for a single core, not all 8.

Sustained 8 core at 3.8 is still better then the spec page 3.6 that intel state for 8 core.

Would it boost more with better cooling. Yes it would. Is it throttling below spec. No.
The maximum clock speed at 8 core is 4.7ghz. 3.8ghz is way lower than what we expected.
 

spiderpumpkin

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Oct 27, 2014
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I currently have the i5 9600K iMac and it runs at a nice constant 4.3ghz when fully loaded. I had the i9 9900K iMac, returned it, and found that one liked to stabilize at 3.8ghz but also jump all over the place.
 
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mrvo

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I currently have the i5 9600K iMac and it runs at a nice constant 4.3ghz when fully loaded. I had the i9 9900K iMac, returned it, and found that one liked to stabilize at 3.8ghz but also jump all over the place.
May I know your usage/application?
Are your previous and current iMac equipped with Vega? If so how are the temps between the two? I keep thinking temps are the same since both are rated 95 TDP, however the 9600K obviously would run at full tilt in the upper turbo range.
 

mcnallym

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Oct 28, 2008
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The maximum clock speed at 8 core is 4.7ghz. 3.8ghz is way lower than what we expected.
Show me where intel claim 4.7ghz sustained with 8 cores!
They don’t they specify 3.6ghz with 8 cores and a turbo boost of 5ghz.

https://ark.intel.com/content/www/us/en/ark/products/186605/intel-core-i9-9900k-processor-16m-cache-up-to-5-00-ghz.html

Specifically read the definition from intel as too max boost speed. Is for a single core.

Feel free to argue with intel as to the definition of turbo boost.

It may not be what you expected, and I am putting together a hack with i9 under a 360mm radiator so expect above 3.8ghz due to better cooling.

Indeed plenty of people are achieving better then 3.8 with 8 cores and all are in better cooled systems.

However the spec sheet doesn’t state 5.0ghz with 8 cores.
 

PBMB

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Mar 19, 2015
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i9 sucks?
It certainly does not, but you cannot expect it to perform at full power in the iMac enclosure. A part of its potential cannot be unleashed.

This is why I ordered a new iMac with the i5 CPU and the Vega 48 GPU. I remember having seen reports showing that it runs cooler than the 580X, even under light system load. I have no idea why but this would leave some more thermal room, so to say, for the CPU to perform better. I would like to do some testing when I receive it but I don't know exactly what.
 
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mavericks7913

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Show me where intel claim 4.7ghz sustained with 8 cores!
They don’t they specify 3.6ghz with 8 cores and a turbo boost of 5ghz.

https://ark.intel.com/content/www/us/en/ark/products/186605/intel-core-i9-9900k-processor-16m-cache-up-to-5-00-ghz.html

Specifically read the definition from intel as too max boost speed. Is for a single core.

Feel free to argue with intel as to the definition of turbo boost.

It may not be what you expected, and I am putting together a hack with i9 under a 360mm radiator so expect above 3.8ghz due to better cooling.

Indeed plenty of people are achieving better then 3.8 with 8 cores and all are in better cooled systems.

However the spec sheet doesn’t state 5.0ghz with 8 cores.
As crazzyeddie showed, i9-9900K's all core turbo speed is 4.7ghz. And recently, Intel announced i9-9900KS with all core turbo at 5ghz.
[doublepost=1560700717][/doublepost]
It certainly does not, but you cannot expect it to perform at full power in the iMac enclosure. A part of its potential cannot be unleashed.

This is why I ordered a new iMac with the i5 CPU and the Vega 48 GPU. I remember having seen reports showing that it runs cooler than the 580X, even under light system load. I have no idea why but this would leave some more thermal room, so to say, for the CPU to perform better. I would like to do some testing when I receive it but I don't know exactly what.
It certianly does because Intel's monopoly made this kind of result as they are not improving their processing which is 14nm since 2015 while AMD has 7nm.
 

velocityg4

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As crazzyeddie showed, i9-9900K's all core turbo speed is 4.7ghz. And recently, Intel announced i9-9900KS with all core turbo at 5ghz.
[doublepost=1560700717][/doublepost]

It certianly does because Intel's monopoly made this kind of result as they are not improving their processing which is 14nm since 2015 while AMD has 7nm.
Also AMD doesn't cheat on TDP much. When they list TDP. That means TDP under full load. Intel has been getting much worse about this with Coffee Lake.

For example
Ryzen 2700x rated TDP 105W actual torture loop 104.7W
Intel i7-8700K rated TDP 95W actual torture loop 159.5W
Intel i7-9900K rated TDP 95W actual torture loop 204.6Wo_O
https://www.tomshardware.com/reviews/intel-core-i9-9900k-9th-gen-cpu,5847-11.html

So, yes Apple's cooling is withing spec. Except Intel's spec sheet is way off. They are claiming the same TDP as an i7-7700K. Which the iMac was fine with. Except actual power usage (heat generation) under full load has nearly doubled.:eek:

If AMD holds true to form. Their Ryzen 3900X will hit a maximum Turbo Core of 4.6Ghz (don't know multi-core max). But 12 cores will do max Turbo Core within 105W. With a better IPC than Intel (performance per Ghz). Come on Apple. Dump Intel. At least for the iMac and Mac Mini. I mean you already love AMD GPUs. Give their CPUs a shot. If you did this with the Mac Pro and Zen 2 Epyc it would have more PCIe lanes, PCIe 4.0 and 64 cores.:cool:
 

Dutch60

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May 18, 2019
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I currently have the i5 9600K iMac and it runs at a nice constant 4.3ghz when fully loaded. I had the i9 9900K iMac, returned it, and found that one liked to stabilize at 3.8ghz but also jump all over the place.
That keeps me wondering if I ordered the wrong iMac (i9 + Vega).
(Edit) No I’ll keep it like it is.
 

mavericks7913

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Also AMD doesn't cheat on TDP much. When they list TDP. That means TDP under full load. Intel has been getting much worse about this with Coffee Lake.

For example
Ryzen 2700x rated TDP 105W actual torture loop 104.7W
Intel i7-8700K rated TDP 95W actual torture loop 159.5W
Intel i7-9900K rated TDP 95W actual torture loop 204.6Wo_O
https://www.tomshardware.com/reviews/intel-core-i9-9900k-9th-gen-cpu,5847-11.html

So, yes Apple's cooling is withing spec. Except Intel's spec sheet is way off. They are claiming the same TDP as an i7-7700K. Which the iMac was fine with. Except actual power usage (heat generation) under full load has nearly doubled.:eek:

If AMD holds true to form. Their Ryzen 3900X will hit a maximum Turbo Core of 4.6Ghz (don't know multi-core max). But 12 cores will do max Turbo Core within 105W. With a better IPC than Intel (performance per Ghz). Come on Apple. Dump Intel. At least for the iMac and Mac Mini. I mean you already love AMD GPUs. Give their CPUs a shot. If you did this with the Mac Pro and Zen 2 Epyc it would have more PCIe lanes, PCIe 4.0 and 64 cores.:cool:
Because of Thunderbolt 3, that's difficult.
 

cynics

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Jan 8, 2012
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Also AMD doesn't cheat on TDP much. When they list TDP. That means TDP under full load. Intel has been getting much worse about this with Coffee Lake.

For example
Ryzen 2700x rated TDP 105W actual torture loop 104.7W
Intel i7-8700K rated TDP 95W actual torture loop 159.5W
Intel i7-9900K rated TDP 95W actual torture loop 204.6Wo_O
https://www.tomshardware.com/reviews/intel-core-i9-9900k-9th-gen-cpu,5847-11.html

So, yes Apple's cooling is withing spec. Except Intel's spec sheet is way off. They are claiming the same TDP as an i7-7700K. Which the iMac was fine with. Except actual power usage (heat generation) under full load has nearly doubled.:eek:

If AMD holds true to form. Their Ryzen 3900X will hit a maximum Turbo Core of 4.6Ghz (don't know multi-core max). But 12 cores will do max Turbo Core within 105W. With a better IPC than Intel (performance per Ghz). Come on Apple. Dump Intel. At least for the iMac and Mac Mini. I mean you already love AMD GPUs. Give their CPUs a shot. If you did this with the Mac Pro and Zen 2 Epyc it would have more PCIe lanes, PCIe 4.0 and 64 cores.:cool:
TDP has never been peak power consumption. Technically its not consumption at all its a energy measurement in watts of heat dissipation that is averaged (because they are two different metrics) at base clock.
Screen Shot 2019-06-16 at 2.47.51 PM.png


Below is out of the i8 or i9 data sheet from intel.

Screen Shot 2019-06-16 at 3.08.53 PM.png


The CPU's have TDP # the same as their PL1 numbers IE base clock. When you start a task PL2 is the limit of power consumption. In the case of the bottom CPU 4-Core GT2/GT0 that would be ~81W of power consumption (65W x 1.25 = 81.25W). In quick task this isn't an issue as 1 core will boost up well into turbo range but since its only a single core it won't exceed 81w of the package design. However if the load gets heavier and more cores are used and 81w of power is exceeded for more than PL1 Tau (8 seconds) the PL1 will be set as the limit.

Here is where this gets interesting. PL1, PL2 and Tau are adjustable by the manufacturer or overclockers which adds all sorts of variables.

With that in mind here is a screen grab from the OP's video.

Screen Shot 2019-06-16 at 4.08.29 PM.png


Notice the temp spiked to 119-120w held for a few seconds and dropped to below 90w? That is a 95w CPU (95w x 1.25=118.75w) aka PL2 held for a few seconds and dropped to PL1. PL1 has been lowered because if you watch the temps they keep creeping up but level out before 100c.

So the OP is right and wrong, the CPU performance is being limited because it would get too hot not because it is getting too hot. Aka its an artificial limit to keep from hitting tjunction max.

The opposite applies too if you had a REALLY good cooling solution and set PL1 to and PL2 to 150w then that is the kind of power consumption you'll see as long as thermal limits aren't hit.

Intel even goes as far as explicitly saying that your cooler should be designed for the heat dissipation at PL1 (TDP) as the minimum.

Screen Shot 2019-06-16 at 4.05.56 PM.png


Peak power consumption can only be defined by the company/person buying it (unlocked) which is why Intel doesn't give that spec. Intel just gives you an average based on their stable base clock designed for longevity.
 
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macdudesir

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Jan 16, 2011
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I think quibbling over the difference is unnecessary, but wanted everyone to have their facts straight.

View attachment 843199

https://www.anandtech.com/show/14402/intel-announces-5-ghz-all-core-turbo-cpu
The keyword - SUSTAINED 8 core is 3.6GHz, NOT anything higher than that.

OP, The i9 does not suck, the iMac does not suck, and it is not overheating. The iMac in question is operating over what should be expected of it. You said yourself, it sustains 3.8GHz which is a sustained turbo boost. So it's sustaining over base clock even in the iMac enclosure. That's great! Turbo boost is not meant to be sustained and as such the cooling system isn't designed to sustain it.

Further, as others have mentioned, nobody is subjecting it to that kind of load all the time. If you're doing pro work you're going to be exposing it to short bursts most likely which means that it will boost fully and will not throttle or get too hot. Just because some guy on youtube threw up a bunch of dev null's and it throttled back the turbo boost doesn't mean you're not getting a great machine that is very powerful.
 

xWhiplash

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The keyword - SUSTAINED 8 core is 3.6GHz, NOT anything higher than that.

OP, The i9 does not suck, the iMac does not suck, and it is not overheating. The iMac in question is operating over what should be expected of it. You said yourself, it sustains 3.8GHz which is a sustained turbo boost. So it's sustaining over base clock even in the iMac enclosure. That's great! Turbo boost is not meant to be sustained and as such the cooling system isn't designed to sustain it.

Further, as others have mentioned, nobody is subjecting it to that kind of load all the time. If you're doing pro work you're going to be exposing it to short bursts most likely which means that it will boost fully and will not throttle or get too hot. Just because some guy on youtube threw up a bunch of dev null's and it throttled back the turbo boost doesn't mean you're not getting a great machine that is very powerful.
Since when did thermal throttling mean NEVER maintaining max turbo boost on all cores forever anyway?
 
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EmlynDewar

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Aug 17, 2011
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Maximum all core turbo, does not mean sustained forever clock speeds. If you want that, buy a tower PC with healthy ventilation...
Unless the CPU is throttling to under 3.6ghz constantly, then it's within spec.

Intel should stop advertising turbo speeds, building unhealthy expectations.
 
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mavericks7913

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Maximum all core turbo, does not mean sustained forever clock speeds. If you want that, buy a tower PC with healthy ventilation...
Unless the CPU is throttling to under 3.6ghz constantly, then it's within spec.

Intel should stop advertising turbo speeds, building unhealthy expectations.
Then it's Intel and Apple's fault. Maximum all core turbo can be sustained with a proper cooling system. Intel's CPU is too hot that you need a water cooler or Noctua air cooler. Apple computer has a weak cooling system that they need to fix it. iMac itself has the same cooling system since 2012! This is a joke for sure.

The turbo speed is not an issue because it's up to a cooling system like Apple. You can overclock all cores up to 4.7ghz but the temperature will be too hot.
 

ridgero

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Dec 16, 2017
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The benchmarks confirm the good performance of the i9.

Linus made a good video about the clockspeeds


5:11
 
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EmlynDewar

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Aug 17, 2011
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Then it's Intel and Apple's fault. Maximum all core turbo can be sustained with a proper cooling system.

...

The turbo speed is not an issue because it's up to a cooling system like Apple. You can overclock all cores up to 4.7ghz but the temperature will be too hot.
Your expectations are too high, turbo should be expected for bursty loads. You're in a thin form factor, and the CPU is behaving as advertised. Better actually...

Maximum clock, it's in the name. It's the max it will go. Just because the 9900 operates great when completely disregarding TDP limits, it doesn't mean it sucks when it sticks within that limit.

I guess it is Intel's fault. They should completely restrict their CPUs from ever running out of spec, so people don't get unrealistic expectations... /s
 

mavericks7913

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The benchmarks confirm the good performance of the i9.

Linus made a good video about the clockspeeds


5:11
iMac compromised the performance by under volting the CPU. With a proper desktop, i9-9900K shouldnt suffers its performance like that.
[doublepost=1560840937][/doublepost]
Your expectations are too high, turbo should be expected for bursty loads. You're in a thin form factor, and the CPU is behaving as advertised. Better actually...

Maximum clock, it's in the name. It's the max it will go. Just because the 9900 operates great when completely disregarding TDP limits, it doesn't mean it sucks when it sticks within that limit.

I guess it is Intel's fault. They should completely restrict their CPUs from ever running out of spec, so people don't get unrealistic expectations... /s
It's not too high. It's totally normal. And yet because of stupid Apple's design, most Macs are throttling. With a normal PC, this can be fixed by adding a nice and big cooler. Why do we have to use a small and thin computer?

LOL not this topic again. I said it's both Intel and Apple's fault. Apple is well known for having a poor cooling performance for A LONG TIME. Did they ever improve the cooling system for iMac? No. Since Apple is not able provide better cooling options, it's Apple's fault too.
 

xWhiplash

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Oct 21, 2009
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iMac compromised the performance by under volting the CPU. With a proper desktop, i9-9900K shouldnt suffers its performance like that.
[doublepost=1560840937][/doublepost]

It's not too high. It's totally normal. And yet because of stupid Apple's design, most Macs are throttling. With a normal PC, this can be fixed by adding a nice and big cooler. Why do we have to use a small and thin computer?

LOL not this topic again. I said it's both Intel and Apple's fault. Apple is well known for having a poor cooling performance for A LONG TIME. Did they ever improve the cooling system for iMac? No. Since Apple is not able provide better cooling options, it's Apple's fault too.
Uh. It’s called the iMac Pro. The did improve the cooling, but it will take some time for the consumer iMac to get it.

It is not Apples fault. With the current cooling system, does the iMac i9 perform within Intels spec? Yes, so the cooling is fine. In fact, Max videos reported its much cooler and runs better than previous generations.
 
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