The new iMac is a lot noisier!

[EugW]

The new iMac is a lot quieter!

The i5-7600 with 1 TB SSD is now in the house. Like the i7-7700K I had before, it idles below 40C in this room which is around 22C, or just around 40C or slightly above when I'm lightly surfing. Of course, in this context, it is silent.

The big difference though is this thing is silent under heavy loads, at least for a good while. Just for fun I loaded up the latest Handbrake nightly and started a transcode of 4K HEVC to 1080p HEVC. This pegged the CPU at 100% load. After about ~10 minutes of this, the fans were still at 1200 rpm (minimum), and the temps were in the low 80s C. I never once saw the power utilization exceed 60 Watts. It hit about 57 Watts a few times, but most of the time was in the 52-55 Watt range. As you can see from the screengrab, the CPU was using over 399%, with Handbrake taking 388% of that.

In contrast, the fan on the i7-7700K would kick in very quickly. At max in well under a minute IIRC.

The Radeon Pro 575 GPU sits around 15 Watts idle, during light surfing with simple pages, and during video encoding, but would be 15-25 Watts while surfing with animated ads in the web pages. (I don't remember exactly what it was on the Radeon Pro 580 but I vaguely recall it was more in the 30+ W range.)

I don't quite hit the nice round 5400 / 16000 numbers in Geekbench 4.1 some people have with this chip, but I am always close. As expected though, the 575 does achieve the magical 100000 threshold for Compute speed.

Geekbench 4.1 CPU: 5352 / 15873
Geekbench 4.1 Compute: 102633

My Core i7 870 gets 2888 / 9415 CPU and 8029 Compute, so this i5 represents approximately an 85% / 70% improvement in CPU speed over the old i7, and it's about 13X as fast for GPU compute.

For reference, the i5-7500 gets 4999 / 14823, so the i5-7600 has about a 7% / 7% advantage over the i5-7500. Not that impressive, but you get the 575, which is roughly 25% faster than the 570 if that matters to you.

tl;dr:

The i5-7600 runs cool, always less than 60 Watts, even with 100% CPU usage. After 10 minutes of 100% CPU load with video encoding, temps in low 80s and fan still at minimum, a huge change from the i7-7700K which would go to maximum fan in the first minute.

Speed is only 7% faster than i5-7600, but the i5-7600 comes with the 575, which is about 25% faster than the 570 that comes with i5-7500.

 

[Falcon80]

The new iMac is a lot quieter!

The i5-7600 with 1 TB SSD is now in the house. Like the i7-7700K I had before, it idles below 40C in this room which is around 22C, or just around 40C or slightly above when I'm lightly surfing. Of course, in this context, it is silent.

The big difference though is this thing is silent under heavy loads, at least for a good while. Just for fun I loaded up the latest Handbrake nightly and started a transcode of 4K HEVC to 1080p HEVC. This pegged the CPU at 100% load. After about ~10 minutes of this, the fans were still at 1200 rpm (minimum), and the temps were in the low 80s C. I never once saw the power utilization exceed 60 Watts. It hit about 57 Watts a few times, but most of the time was in the 52-55 Watt range. As you can see from the screengrab, the CPU was using over 399%, with Handbrake taking 388% of that.

View attachment 707280

In contrast, the fan on the i7-7700K would kick in very quickly. At max in well under a minute IIRC.

The Radeon Pro 575 GPU sits around 15 Watts idle, during light surfing with simple pages, and during video encoding, but would be 15-25 Watts while surfing with animated ads in the web pages. (I don't remember exactly what it was on the Radeon Pro 580 but I vaguely recall it was more in the 30+ W range.)

I don't quite hit the nice round 5400 / 16000 numbers in Geekbench 4.1 some people have with this chip, but I am always close. As expected though, the 575 does achieve the magical 100000 threshold for Compute speed.

Geekbench 4.1 CPU: 5352 / 15873
Geekbench 4.1 Compute: 102633

My Core i7 870 gets 2888 / 9415 CPU and 8029 Compute, so this i5 represents approximately an 85% / 70% improvement in CPU speed over the old i7, and it's about 13X as fast for GPU compute.

For reference, the i5-7500 gets 4999 / 14823, so the i5-7600 has about a 7% / 7% advantage over the i5-7500. Not that impressive, but you get the 575, which is roughly 25% faster than the 570 if that matters to you.

tl;dr:

The i5-7600 runs cool, always less than 60 Watts, even with 100% CPU usage. After 10 minutes of 100% CPU load with video encoding, temps in low 80s and fan still at minimum, a huge change from the i7-7700K which would go to maximum fan in the first minute.

Speed is only 7% faster than i5-7600, but the i5-7600 comes with the 575, which is about 25% faster than the 570 that comes with i5-7500.

Thanks for sharing your initial impression. Hope to hear more positives while I wait for mine to arrive.

 

[propower]

Yes - great report on the 7600. Would be interested what Turbo goes to in one of those Handbrake renders if you get a chance.

 

[dcottuli]

Had my new iMac for a week now and have yet to hear the fans come on. I have the 27" 4.2 GHz 40 GB RAM and 1 TB SSD - super impressed. And so glad that the Mac now turns on quietly

 

[raz_ski]

Hi
I received my new Imac Yesterday....what a stunning display
I have a 2017 27inch i7 1t SSD... and i was a bit worried after reading this thread about the fan noise

Have to say during every-day tasks the fans are not ramping up too much.... so that is a big relief for me... to be honest it's perfectly fine with me to get some fan noise when doing CPU intensive tasks
BUT
Am I the only one that is getting annoyed with the fan noise @1200 RPM?
I hear the airflow continuously and i hear some kind of rolling sound from the fan too..
When i lower the fan speed below the specs, to 1100 RPM then it becomes effectively silent

Someone with the same experience?

 

[Huggi]

I got my i7 7700K today. In idle and web-browsing etc. it´s super silent in compare to my 2009 Mac Pro. Just trying som Handbrake now and my fan runing in max speed. Oki it´s not silent but much more silent than my mac pro that ramps up and down constant under max load.

I will not run handbrake on my iMac. I have a gaming PC for such tasks. My mac is just for daily tasks and some photo editing and 3D modelling.

 

[rico7578]

I will not run handbrake on my iMac. I have a gaming PC for such tasks. My mac is just for daily tasks and some photo editing and 3D modelling.

3D modelling -> i7 -> noise
less noise than mac pro 2009 ok maybe, but still noise...

 

[Huggi]

3D modelling -> i7 -> noise
less noise than mac pro 2009 ok maybe, but still noise...

I imagine the moddeling is GPU intensive, not CPU intensive. Rendering is another ting =) If i wanted a super silent powerfull computer all the time I have looked in other direction than iMac =)

Mac Pro or a Hacktintosh maybe...

 

[DRuser]

Hi
I received my new Imac Yesterday....what a stunning display
I have a 2017 27inch i7 1t SSD... and i was a bit worried after reading this thread about the fan noise

Have to say during every-day tasks the fans are not ramping up too much.... so that is a big relief for me... to be honest it's perfectly fine with me to get some fan noise when doing CPU intensive tasks
BUT
Am I the only one that is getting annoyed with the fan noise @1200 RPM?
I hear the airflow continuously and i hear some kind of rolling sound from the fan too..
When i lower the fan speed below the specs, to 1100 RPM then it becomes effectively silent

Someone with the same experience?

Same here. How did you lower the base fan RPM? With the hack mentioned earlier in this thread?

 

[raz_ski]

yes via this method
https://discussions.apple.com/message/29572550#29572550

but this Mac fan control is not very convenient. i would like to use HDD Fan controls to set the target speed of the fan bases on temperature

@DRuser do you also hear this sound from the bearings of the fan?

 

[EugW]

Yes - great report on the 7600. Would be interested what Turbo goes to in one of those Handbrake renders if you get a chance.

As advertised, with the chip in quad-core Turbo mode, the Core i5-7600 locks itself to exactly 3.90 GHz. Here is the Handbrake test as requested:

The above application is Intel Power Gadget. Luckily, this one year-old version of Intel Power Gadget seems to work fine on the i5-7600. (However, it does seem to need an update for some Kaby Lake CPUs, since for my Core m3-7Y32 and all the other 2017 MacBooks, the base clock is always listed as 1.3 GHz and the Turbo clock is always listed as 2.6 GHz, regardless if it's an m3 or an i7.)

Note that as the applications were loading up, the graph plot spiked to just a touch over 4.0 GHz. Intel states that for single-core Turbo, it is 4.1 GHz, so this is just as expected. When I bought my i7 870 I told myself I wouldn't buy another iMac unless it was one with a 4 GHz clock speed. Achievement unlocked! Sorta.

I also tried the same thing in Cinebench R15's multi-core benchmark. Again, clock speed locked to exactly 3.90 GHz, and it didn't budge from there for the duration of the test.

Note the Core i7 870 I have gets 492. I only got 622 with this i5-7600, but I hadn't shut off all the background processes. Tom's gets 653 multi-core.

So, taking these numbers we can expect only about a 25-35% improvement in multi-core rendering performance going from a Core i7 870 to a Core i5 7600. Cinebench really loves HyperThreading. OTOH, the speed more than doubles if you go to the i7 7700K, which is one reason I originally purchased the i7.

I then also tried Cinebench with their single-thread test. There I saw that the Intel Power Gadget graph was right around 4 GHz, with the spike initially just barely breaching that threshold. That makes sense, as it's probably more around at least 2-core mode, which is 4.0 GHz according to the Intel specs, with one core dedicated to Cinebench and the other core running other stuff. Looking at the numbers alone and not the graph, I'd see it flutter around 3.93 to 3.98 GHz.

Also note the core temps. They max out in the 60s but then slowly climb from there. I mentioned yesterday I hit the low 80s but that was after 10 minutes, and the temp curve was near flat. Maybe if I had let the encode run for half an hour or something, the fan might have sped up a little, but I don't think the fan would ever hit more than moderate under this load, and it's quite possible it wouldn't ramp up at all. Certainly last night playing around with the machine for a couple of hours, I never once saw the fan over 120x rpm. (The iStat Menus reading would fluctuate from around 1195 rpm to 1205 rpm.) Same goes for this morning's Cinebench tests. In stark contrast to this, the i7-7700K would hit 100C fairly quickly, with the fan at max 2700 rpm.

So overall, I am very pleased with this i5-7600. Multi-threaded encoding speeds are way slower than the i7-7700K, but as mentioned before I don't do long encodes very often, and it is very nice to be able to sit at the same desk as this iMac noise-free, even when the CPU is pegged with 100% load.

tl;dr:

Multi-core Turbo Boost confirmed to be 3.90 GHz, and the machine is happy to chug along at that 3.90 GHz indefinitely. Temps slowly climbed during testing, but fan stayed quiet at its minimum speed of 1200 rpm.

Low-thread Turbo Boost confirmed to spike just above 4 GHz, with Cinebench single-core hitting about 3.98 GHz (with additional other applications loaded in the background like Intel Power Gadget, etc.).

 

[Moriarty]

Those 7600 numbers seem about right. Under the same Handbrake test, running for several minutes, my 7600K with turbo off (3.8 GHz) takes about 42 watts with Handbrake, and gets up to around 78 degrees. Turn on Turbo (4 GHz) and you get 53 W, and 91 degrees (room temp is 23.5 degrees). The fan is still idle, but you wouldn't need much more load to spin it up.

There are some uncertainties (differences in chip quality / room temp / heatsink temperature / background tasks / the videos used for encoding) that can vary things by a few degrees / watts, but there's clearly a rather small difference between the 7600 and 7600K.

Note that my CPU power consumption figures in this post are from the Intel Power Gadget... there seems to be a bit of a difference between what the Intel tool reports, and what iStat reports (e.g. iStat says 61 W when Intel says 54 W). I'm not sure what's up with that.

My 580 uses around 33 W with animated ads, from iStat, so it sounds right that the 575 might use a bit less even under light load. That being said, the GPU still runs much cooler than the CPU so it's never an issue.

5.3% extra speed takes 26% more power. We're way past the watts-per-MHz sweet spot.

 

[EugW]

Those 7600 numbers seem about right. Under the same Handbrake test, running for several minutes, my 7600K with turbo off (3.8 GHz) takes about 42 watts with Handbrake, and gets up to around 78 degrees. Turn on Turbo (4 GHz) and you get 53 W, and 91 degrees (room temp is 23.5 degrees). The fan is still idle, but you wouldn't need much more load to spin it up.

There are some uncertainties (differences in chip quality / room temp / heatsink temperature / background tasks / the videos used for encoding) that can vary things by a few degrees / watts, but there's clearly a rather small difference between the 7600 and 7600K.

Note that my CPU power consumption figures in this post are from the Intel Power Gadget... there seems to be a bit of a difference between what the Intel tool reports, and what iStat reports (e.g. iStat says 61 W when Intel says 54 W). I'm not sure what's up with that.

My 580 uses around 33 W with animated ads, from iStat, so it sounds right that the 575 might use a bit less even under light load. That being said, the GPU still runs much cooler than the CPU so it's never an issue.

5.3% extra speed takes 26% more power. We're way past the watts-per-MHz sweet spot.

Yes, iStat says my CPU uses up 55 Watts, but Intel Power Gadget tells me it's more like 43 Watts. (This is with Turbo on. I haven't tried with Turbo off.)

So it seems if you want the Radeon Pro 580, the 7600K is a decent choice if you want a quiet machine, but in certain scenarios you may need to turn off Turbo to keep the heat production in check. 91C is a little close for comfort.

The 7600 has a lower Turbo Boost speed, but it can keep that speed going for a long time without bringing the temps quite as high as the 7600K, so effectively its real world quiet speed is 3.9 GHz. The real world quiet speed of the 7600K MIGHT be 4.0 GHz but it also MIGHT be 3.8 GHz depending on the chip lottery. But either way, it's effectively the same as the 7600, give or take a few percent. But with the 7600 you have the added option of going even lower by turning its Turbo off for 3.5 GHz, which is even cooler.

Ultimately, it seems the big decision here would be if you're interested in the 575 or the 580. Get the 580 if you want GPU speed, but be prepared that you MIGHT have to turn off Turbo under load if you don't like fan noise, or else get the 575 if you don't need the speed or extra RAM of the 580. Overall though, both the 7600 and 7600K seem to be big improvements over the 7700K in terms of max power utilization, and this appears to be in agreement with the PC tests of these chips out there too.

BTW, one other poster mentioned cool temps with the i5-7500 at all times, even with hours of transcoding 4K video. That's the coolest of them all:

i5 7500: Always cool
i5 7600: Likely always cool, but probably a bit warmer than the 7500
i5 7600K: Pretty cool, but can get a bit toasty with Turbo on. Does much better with Turbo off.
i7 7700K: Quite hot under load, but much faster for multi-threaded tasks.

 

[MMcCraryNJ]

Seeing those benchmark numbers for the i5 was very helpful, thank you. Out of curiosity, I downloaded Geekbench to run on my 2012 MBP, just to use as a comparison point.

I scored 3752/12565.

So it seems like, whenever I'm ready to purchase, I really *should* go for the maxed out i7 in order to see any substantial benefit in CPU power. The heat is a concern for sure, and it just might make me hold off until the next iMac to see if they re-do the cooling system ala the iMac Pro.

 

[Fishrrman]

Just to reiterate:
The "base" 27" iMac (3.4ghz) gets the 7500?
and
The "mid" 27" iMac (3.5ghz) gets the 7600?

Is that correct?

 

[Tjmckay4]

Just to reiterate:
The "base" 27" iMac (3.4ghz) gets the 7500?
and
The "mid" 27" iMac (3.5ghz) gets the 7600?

Is that correct?

Yes, that's correct.

 

[DRuser]

yes via this method
https://discussions.apple.com/message/29572550#29572550

but this Mac fan control is not very convenient. i would like to use HDD Fan controls to set the target speed of the fan bases on temperature

@DRuser do you also hear this sound from the bearings of the fan?

No, I didn't hear anything besides this constant stream of air coming out of the vent. To me it looks like a poor design to have the vent so close to the stand. This increases noise. What I did for a quick test was duct taping some aluminium foil shaped like a tunnel covering the vent. With this mod the airstream goes downwards instead of straight out of the vent hitting the stand. It did make a difference in terms of noise, however this is probably only noticeable for a noise-sensitive person.

Thanks for the link, looks like an easy way to bring the base rpm down. I've tried to do it with cheatengine as I wasn't aware of this hack. The few seconds I've had a stable system doing it this way I've noticed that an rpm of 800 - 1000 would be a noise level I would love to have.

Anyway, I returned my 7600k/580 so I can't do any further tests, sorry.

 

[MacDevil7334]

Yes, iStat says my CPU uses up 55 Watts, but Intel Power Gadget tells me it's more like 43 Watts. (This is with Turbo on. I haven't tried with Turbo off.)

So it seems if you want the Radeon Pro 580, the 7600K is a decent choice if you want a quiet machine, but in certain scenarios you may need to turn off Turbo to keep the heat production in check. 91C is a little close for comfort.

The 7600 has a lower Turbo Boost speed, but it can keep that speed going for a long time without bringing the temps quite as high as the 7600K, so effectively its real world quiet speed is 3.9 GHz. The real world quiet speed of the 7600K MIGHT be 4.0 GHz but it also MIGHT be 3.8 GHz depending on the chip lottery. But either way, it's effectively the same as the 7600, give or take a few percent. But with the 7600 you have the added option of going even lower by turning its Turbo off for 3.5 GHz, which is even cooler.

Ultimately, it seems the big decision here would be if you're interested in the 575 or the 580. Get the 580 if you want GPU speed, but be prepared that you MIGHT have to turn off Turbo under load if you don't like fan noise, or else get the 575 if you don't need the speed or extra RAM of the 580. Overall though, both the 7600 and 7600K seem to be big improvements over the 7700K in terms of max power utilization, and this appears to be in agreement with the PC tests of these chips out there too.

BTW, one other poster mentioned cool temps with the i5-7500 at all times, even with hours of transcoding 4K video. That's the coolest of them all:

i5 7500: Always cool
i5 7600: Likely always cool, but probably a bit warmer than the 7500
i5 7600K: Pretty cool, but can get a bit toasty with Turbo on. Does much better with Turbo off.
i7 7700K: Quite hot under load, but much faster for multi-threaded tasks.

Just wanted to say thanks for doing all these tests. I have a i5 7600/Radeon 575 model waiting at the Apple store for me to pick up when I get back from visiting family later this week. Your tests have given me great peace of mind that I made the right decision going with the mid-tier model over the i7/580 model.

 

[DRuser]

Does anyone know why Cinebench shows the i5 7500/7600(k) as 2C/4T? IMHO it should show up as 4C/4T.

 

[montanaco]

Just to throw my experience in the mix, I have the pro 580, i7 model and have been gaming on it nonstop...I haven't heard the fans once.

 

[tozz]

Just to throw my experience in the mix, I have the pro 580, i7 model and have been gaming on it nonstop...I haven't heard the fans once.

Gaming doesn't say much, playing World of Warcraft my 7700K was below 50, very few games actually take advantage of a modern CPU (that's why 95% of all games see no benefit of going i7 over i5). The GPU usage also varies wildly on how and what you're playing, I saw temp ranging from 60 to 75 on a 1080. So for people to be able to get a reference you need to specify which games
Personally I couldn't care less if the machine was making noises while gaming, but I want it to be silent when working in Photoshop.

 

[EugW]

Does anyone know why Cinebench shows the i5 7500/7600(k) as 2C/4T? IMHO it should show up as 4C/4T.

Bug.

 

[raz_ski]

@EugW any difference between you 7700K and 7600 in fan noise when idle?
in other words is the sound of 1200RPM on both Macs the same?

i like to find out if my 7700k is faulty or not

 

[DRuser]

Bug.

thanks

 

[EugW]

@EugW any difference between you 7700K and 7600 in fan noise when idle?
in other words is the sound of 1200RPM on both Macs the same?

i like to find out if my 7700k is faulty or not

Yes, identical. But it seems some of us are less sensitive than others to the 1200 rpm sound. I only really notice it if I stick my ear within about a foot or so of the bottom of the iMac, but I don't sit that close.

Note though that in my room at the other end about 12 feet away is a NAS with some spinning drives and a fan on low. It puts out just a bit of noise that I can sometimes hear from across the room. So, it may mask any noise coming from the iMac, I dunno. Maybe if my room were 100% silent with no NAS in it, I might notice the iMac, but that's not my environment.

The other thing is I might have the iMac a bit further away from the wall than others, so maybe there is less of an amplification effect from the wall.