2019 iMac - i5 vs i9? Cooling and Throttling?

[ondert]

How is the vega 48 only a minor upgrade from the 580? 580 has a open CL of 110k ves the almost 150k of the vega?
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How does a restricted 9900k compared to a regular 9600k

My RP580 in 2017 iMac gets about 123k score in OpenCL, and RP580X will get slightly higher probably closer to 130k score, so it is not that much considering the price difference if Vega 48 gets 150k unless it provides something useful like faster rendering etc. We know it will run cooler than Polaris cards.

For the cpu part, don’t worry i5-9600k will also be restricted to 95w.

 

[BigBoy2018]

So the reviews will expose any i9 throttling that occurs and compare the performance of the "throttled" i9 to the non-throttled high end i5? Or, do they both get throttled? Sounds like most people are waiting to see this to figure out which configuration is best to order....hopefully soon!

Unfortunately, most reviews don’t stress the system in a meaningful way. They often just show geekbench scores and other benchmarks that are deceptive since they don’t take long enough to actually test the thermals of the processor.
That’s why a 2.3 ghz processor with turbo boost to 4ghz will get a similar geekbench score to a 3.4ghz processor with turbo boost to 4ghz. Same geekbench scores, but they are far from equivalents.

 

[craigrusse11]

If Apple is limiting to 3.6GHz at 8 cores, then why the hell are they advertising Boost upto 5GHz?

Exactly, those expectations have been set when the customer hits add to basket. Apple need to be more open in what’s been sold.

 

[quagmire]

If Apple is limiting to 3.6GHz at 8 cores, then why the hell are they advertising Boost upto 5GHz?

Exactly, those expectations have been set when the customer hits add to basket. Apple need to be more open in what’s been sold.

Cause that 5 GHz turbo speed is when only 1-2 cores are loaded and there is thermal headroom for it. As more cores are loaded, the lower the clock speed. That’s been the whole premise of Intel’s turbo feature when it came out. When the full CPU’s capacity wasn’t needed and if it could thermally, the remaining cores could go at a higher frequency.

This is what Anandtech found when they restricted it to its 95W rating. Yes one allowed to go above it can sustain a faster clockspeed given it can be cooled. But it’s reasonable to believe Apple restricted its power consumption thus when loading all 7-8 cores, does it drop close to its base clock.

 

[BigBoy2018]

Then how do you explain the 33000 geekbench score people are getting? That is a major upgrade over the 2017 update.

Geekbench isn’t a good representation.

The short time it takes for the geekbench test means the processor can run at full turbo boost throughout. So a 2.3ghz processor with a turbo boost to 4ghz would get the same score as a 3.4ghz processor with a 4ghz turbo boost.

But they’re hardly going to perform the same in real world use.

 

[jonatious]

Cause that 5 GHz turbo speed is when only 1-2 cores are loaded and there is thermal headroom for it. As more cores are loaded, the lower the clock speed. That’s been the whole premise of Intel’s turbo feature when it came out. When the full CPU’s capacity wasn’t needed and if it could thermally, the remaining cores could go at a higher frequency. But it would run at its base clock when all cores are loaded. It was never advertised as running at the turbo speeds when every core was pegged.

This is what Anandtech found when they restricted it to its 95W rating. Yes one allowed to go above it can sustain a faster clockspeed given it can be cooled. But it’s reasonable to believe Apple restricted its power consumption thus when loading all 7-8 cores, does it drop close to its base clock.

I am okay with 8 cores running at 4.7k but not at 3.6k :/
I was expecting more power from the machine

/e nvm guys, I understood now

 

[quagmire]

I am okay with 8 cores running at 4.7k but not at 3.6k :/
I was expecting more power from the machine

Then build your own PC with water cooling and don’t restrict it. As long as it doesn’t drop below the base clock, your expectations were too high and shouldn’t be complaining that an 8 core CPU advertised to run at 3.6 GHz on all cores actually runs at 3.6 GHz on all cores. The iMac as of now is running as advertised.

 

[kaintxu]

My RP580 in 2017 iMac gets about 123k score in OpenCL, and RP580X will get slightly higher probably closer to 130k score, so it is not that much considering the price difference if Vega 48 gets 150k unless it provides something useful like faster rendering etc. We know it will run cooler than Polaris cards.

For the cpu part, don’t worry i5-9600k will also be restricted to 95w.

Yes, but even if restricted, it won't be affected as much as the 9900K, as that one goes up to much higher TDP. What I mean is that if you restrict the 9900K to 95W you might be almost halving it's potential, while if you restrict the 9600K it might just be a 20-30% cap.

I am okay with 8 cores running at 4.7k but not at 3.6k :/
I was expecting more power from the machine

Also, apple does not advertise 8 cores at 4.8K They advertise OC at 5K, which even limited at 95W you get for 1 Core, and you still get 4700 for up to 6 cores at 95W limit.

The 8 cores at 4.7K are the spec for the unrestricted 9900K which you won't get on an AIO. As it has been mentioned, for full-fat processor performance, PC with water cooling. Want an AIO, be prepared to sacrifice something. I also want a 1080Ti on my AIO, but it is not happening, so I have to live trying to decide whether is worth paying £400 for a vega 48, which is far from its real cost as you can get a 2070 for that price.

 

[quagmire]

Yes, but even if restricted, it won't be affected as much as the 9900K, as that one goes up to much higher TDP. What I mean is that if you restrict the 9900K to 95W you might be almost halving it's potential, while if you restrict the 9600K it might just be a 20-30% cap.



Also, apple does not advertise 8 cores at 4.8K They advertise OC at 5K, which even limited at 95W you get for 1 Core, and you still get 4700 for up to 6 cores at 95W limit.

The 8 cores at 4.7K are the spec for the unrestricted 9900K which you won't get on an AIO. As it has been mentioned, for full-fat processor performance, PC with water cooling. Want an AIO, be prepared to sacrifice something. I also want a 1080Ti on my AIO, but it is not happening, so I have to live trying to decide whether is worth paying £400 for a vega 48, which is far from its real cost as you can get a 2070 for that price.

The 9900K also has a TDP of 95W. It just isn’t a hard limit if there is no restriction placed on it.

Since the focus has been on the 9900K, I haven’t found info if the 9600K is also allowed to go above the 95W limit if not restricted and by how much. I have found the 9600K doesn’t run much cooler than the 9900K though. At least in the setup the testers have run. Who knows if it will run cooler if restricted to 95W.

 

[kaintxu]

The 9900K also has a TDP of 95W. It just isn’t a hard limit if there is no restriction placed on it.

Since the focus has been on the 9900K, I haven’t found info if the 9600K is also allowed to go above the 95W limit if not restricted and by how much. I have found the 9600K doesn’t run much cooler than the 9900K though. At least in the setup the testers have run. Who knows if it will run cooler if restricted to 95W.

I'm annoyed at everyone for just getting 9900Ks hahahahha, I Really want to see some stress tests on the 9600K so I Can decide.

The thing is, running at those 94ish degrees is not too bad is it?

 

[jonatious]

Then build your own PC with water cooling and don’t restrict it. As long as it doesn’t drop below the base clock, your expectations were too high and shouldn’t be complaining that an 8 core CPU advertised to run at 3.6 GHz on all cores actually runs at 3.6 GHz on all cores. The iMac as of now is running as advertised.

I get it now. But at 6 cores I get 4.7k which is around 28k speed, at 7 cores I get 3.6k, which reduces the overall speed to 25k and at 8 cores at 3.6k I get an overall speed of 28.8k.

Why do I need the 7th and 8th cores then? Sorry if I am missing something here

 

[quagmire]

I'm annoyed at everyone for just getting 9900Ks hahahahha, I Really want to see some stress tests on the 9600K so I Can decide.

The thing is, running at those 94ish degrees is not too bad is it?

I’m not comfortable at it running at those temps. It’s below the 105 C limit before Intel’s protections will force shut it down, but who knows how much the surrounding components can take the heat especially if you still have a spinner. Heat loves to kill normal HDD’s.

I will likely manually turn up the fan to cool it off as I have with my current iMac. Rather have fan noise and have it run cooler than quiet and have cooking silicon inside.

 

[mcnallym]

I am okay with 8 cores running at 4.7k but not at 3.6k :/
I was expecting more power from the machine

On the i9 9900k processor page then is pretty clear.

8 cores
95w tdp
Processor base frequency 3.6Ghz
Max turbo frequency 5.00 GHz

Max turbo frequency is the maximum single core frequency at which the processor is cable of operating using intel turbo boost technology and if present intel thermal velocity boost.

Seems cpu is running within intel specs to me.

Of course with better cooling then more chance of getting more cores at higher boost speeds but all intel claim is 8 cores at 3.6 which the iMac seems to do.

 

[adamk77]

 

 

[joema2]

Yes an unrestricted 9900K with proper cooling can sustain all core of 4.7 GHz. When Anandtech limited it to 95W, all core would only sustain 3.6 GHz. If one was expecting an unrestricted 9900K in the iMac’s enclosure, think those expectations were set wrong.

I agree with your point about people having wrong expectations. Nowhere does Apple state the i7-9900k in the 2019 iMac will run all cores at 5Ghz or 4.7Ghz. Apple's product page clearly says 3.6Ghz, turbo boost to 5Ghz. Like any other PC manufacturer, that is referring to Intel's turbo boost behavior for a single core in the default 95W TDP mode, not the thermally unrestricted mode.

Does Dell or HP make an air-cooled business-class tower configured by default with an unrestricted i7-9900k? For that matter does any mainstream commercially manufactured PC ship configured by default with an air-cooled unrestricted i7-9900k? Is a sustained all core 4.7Ghz clock under high load even possible on the i9-9900k with any reasonable air cooling solution?

Maybe this is possible -- I don't know. But this is an iMac forum and the reasonable comparison would be to other mainstream commercially-manufactured business-class PCs.

If those are not shipped and supported with an unrestricted i7-9900k capable of sustained high-load all-core operation at 4.7Ghz on air cooling, then I don't see how the iMac or iMac Pro form factor is relevant. It wouldn't matter how thick the iMac was, or even if it had a Noctua NH-D15 sticking out the back. If you have to use liquid cooling to reliably maintain all core 4.7Ghz operation at high load, or if no mainstream manufacturer ships business-class air-cooled i7-9900k machines which disregard Intel's TDP, then what is Apple supposed to do? Open a new product line for water-cooled gaming Macs? Some people would like that but until that happens I don't see how what Apple has done with the i7-9900k is that different from other commercially-manufactured air-cooled business-class machines.

 

[smetvid]

Personally I'm ok with the i9 doing what it does on the iMac. I buy a Mac compared to other Macs and not compared to a PC which I have no interest in. Compared to every other Mac other than the iMac Pro the i9 iMac is the fastest Mac. Thats all that really matters.

Not if 8 cores run at 3.6ghz or 3.9ghz or 4.7ghz. Sure it would be nice if the iMac could be even faster but I'm not going to lose any sleep over it because Macs are well optimized with the applications I use and I would take FCPX running on 8 cores at a constant 3.6ghz vs a PC with Premiere running 8 cores at a constant 4.7ghz anyday due to how well FCPX utilizes the hardware.

All that really matters here is how fast the iMac is compared to other Macs. Anything else is irrelevant.

 

[amoergosum]

 

[adamjackson]

I miss blogs.

 

[dimme]

Do we think a 3.7 9th gen i5 and a 580x would be a cool stable solution? I have a 2015 27" 5K and the fans hardly ramp up and it runs cool. I am looking for the same experience.

 

[patearrings]

Do we think a 3.7 9th gen i5 and a 580x would be a cool stable solution?

This is also what i am looking at buying so would appreciate any help.

 

[Rockadile]

Then build your own PC with water cooling and don’t restrict it. As long as it doesn’t drop below the base clock, your expectations were too high and shouldn’t be complaining that an 8 core CPU advertised to run at 3.6 GHz on all cores actually runs at 3.6 GHz on all cores. The iMac as of now is running as advertised.

Yes, but even if restricted, it won't be affected as much as the 9900K, as that one goes up to much higher TDP. What I mean is that if you restrict the 9900K to 95W you might be almost halving it's potential, while if you restrict the 9600K it might just be a 20-30% cap.



Also, apple does not advertise 8 cores at 4.8K They advertise OC at 5K, which even limited at 95W you get for 1 Core, and you still get 4700 for up to 6 cores at 95W limit.

The 8 cores at 4.7K are the spec for the unrestricted 9900K which you won't get on an AIO. As it has been mentioned, for full-fat processor performance, PC with water cooling. Want an AIO, be prepared to sacrifice something. I also want a 1080Ti on my AIO, but it is not happening, so I have to live trying to decide whether is worth paying £400 for a vega 48, which is far from its real cost as you can get a 2070 for that price.

I agree with your point about people having wrong expectations. Nowhere does Apple state the i7-9900k in the 2019 iMac will run all cores at 5Ghz or 4.7Ghz. Apple's product page clearly says 3.6Ghz, turbo boost to 5Ghz. Like any other PC manufacturer, that is referring to Intel's turbo boost behavior for a single core in the default 95W TDP mode, not the thermally unrestricted mode.

Does Dell or HP make an air-cooled business-class tower configured by default with an unrestricted i7-9900k? For that matter does any mainstream commercially manufactured PC ship configured by default with an air-cooled unrestricted i7-9900k? Is a sustained all core 4.7Ghz clock under high load even possible on the i9-9900k with any reasonable air cooling solution?

Maybe this is possible -- I don't know. But this is an iMac forum and the reasonable comparison would be to other mainstream commercially-manufactured business-class PCs.

If those are not shipped and supported with an unrestricted i7-9900k capable of sustained high-load all-core operation at 4.7Ghz on air cooling, then I don't see how the iMac or iMac Pro form factor is relevant. It wouldn't matter how thick the iMac was, or even if it had a Noctua NH-D15 sticking out the back. If you have to use liquid cooling to reliably maintain all core 4.7Ghz operation at high load, or if no mainstream manufacturer ships business-class air-cooled i7-9900k machines which disregard Intel's TDP, then what is Apple supposed to do? Open a new product line for water-cooled gaming Macs? Some people would like that but until that happens I don't see how what Apple has done with the i7-9900k is that different from other commercially-manufactured air-cooled business-class machines.

I have a 9900K running all-core 5.1GHz with Noctua NH-D15S that has 120mm and 140mm fan on it. Swapped the fans with Corsair ML series for aesthetics though, not using Noctua fans. So you don't need water cooling for this chip. You'll need full custom water cooling if you really want some worthwhile chilly temps.
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I am okay with 8 cores running at 4.7k but not at 3.6k :/
I was expecting more power from the machine

/e nvm guys, I understood now

It's 10-20% difference in performance.
Since Apple gimped a mid-range option (9700K), it's still worth getting the i9.
If I ever built a small case PC than I would still use a 95W limited 9900K.

 

[TVreporter]

Good initial results for the i9

 

[jinnyman]

It's meaningless for a regular 9900K but this is clearly acting similar to one with it's power limited to 95W. I don't see an unrestricted 9900K going all-core 4.7GHz in an AIO.

My custom PC with air cooling goes 4.7 continuous with nh-d15 cooler. Only when I try the stress test tools like Linx then I become uncomfortable (seldom reach 90 degree celcious). So it's possible. 4.7 is base turbo clock without any overclocking and it's doable. all time overclock to 5.3 I decided to not do. But you are right. I don't see anyone using i9 with full turbo in AIO.

Anyhow, back to the topic, I'm quite ok with Apple limiting continuous turbo to 3.8 (aka limit TDP). iMac is all in one, and while the performance is needed, it's famous for stability and silence operation. The i9 in iMac is perfectly meant for this, offering the advertised performance in very stable platform. I'm actually considering buying this iMac as this I Believe is going to be the last iMac before Arm and/or T2 when they do change over.

 

[Hawkeye66]

In case anyone is interested -
2019 21.5 Imac, I7, 16GB, Pro Vega 20
FCPX stabilize 20 minute clip. At ~100% CPU, core frequency was still at 3.5, CPU at ~100C. Fan was moving a good amount of air.
Doesn't seem to throttle that much.

 

[joema2]

I have a 9900K running all-core 5.1GHz with Noctua NH-D15S that has 120mm and 140mm fan on it....you don't need water cooling for this chip...

If you simultaneously run Intel Burn Test 2.54 and Furmark GPU stress for several hours, how does it hold up at 5.1 Ghz on air cooling?

https://www.techspot.com/downloads/4965-intelburntest.html
https://geeks3d.com/furmark/