The new iMac is a lot noisier!

[EugW]

The 7600K is unlocked for clock speed. You can run it as fast as you can a) keep it stable, b) keep it below thermal runaway. I can blow up a 125W Mosfet by running it without a heatsink. Or I can thermally cool it and run - 125W (I designed power supplies and audio gear for many years...). I believe the higher rating for both the K parts is about maximum rating even with stellar cooling - or perhaps what the equvalent power for the maximum useable frequency is. The home PC builders mostly pride themselves on 60degC max temp at whatever Overclocking they desire. The rating on the chip I believe means the same - like - maybe it can do 5GHz if you can get the heat out. I do not think it means that this chip is all the sudden 91W at the same freq as the non-K version

Yes it's unlocked, but as you know that's irrelevant for iMacs.

However, what I was pointing out is that under very heavy load, some of the 7600K chips do run a fair bit warmer. Tom's 7600K used 15 more Watts power than the 7600 under their FPU Max Load test. And for their power virus like test, the 7600K used a whopping 31 W more.

Thus, it would seem that the 7600 is pretty much guaranteed to run cool, while the 7600K might run cool, or it might run somewhat more toasty in some instances. It would appear that the 7600's clock speed is the sweet spot, and to get to the 7600K's somewhat higher base clock speed and the marginally higher multi-core Turbo clock speed, some compromises might have had to have been made.

Even for just normal gaming loads, Tom's measured their 7600 to consume 42 Watts for their CPU package and 32 Watts for the cores, but their 7600K hit 55 Watts and 45 Watts respectively. Again, that is a 13 Watt difference between the two chips.

So I will restate my assessment from before, more or less:

i5-7500: Guaranteed to be silent. Has the base GPU (570).
i5-7600: Pretty much guaranteed to be silent. Has a faster GPU (575).
i5-7600K: Probably will be silent, but not absolutely guaranteed. Has the fastest (and hottest) GPU (580).
i7-7700K: Will not be silent under heavy CPU load, regardless of how much the GPU (580) is working.

---

That's why I'd like to see a few Handbrake h.265 encode tests (using the nightly release) on the 7600K. I could get my 7600 quite a bit warmer (83C) with that test than I could with the yes test (76C).

 

[propower]

No need for my post...

 

[EugW]

We actually agree ... Turbo ON and Turbo OFF for my last test showed 51W/41W for the 7600K. The 41W for 3.8GHz 7600K maps pretty well to the Toms article for the 3.9GHz turbo 7600. My 51W is reasonably close for Turbo ON 7600K as well. All I am saying is that the 7600 and the 7600K are much more alike than different. But I believe you know much more about these than I. I will go back to just stating facts as I find them

Nah, I don't think I know any more than you do. I'm just quoting what Tom's wrote. I probably know a lot less since I don't know anything about audio.

It's good to have all these data points, though. Everyone, keep them coming!

I think one way of interpreting and extrapolating from the data we have is that if you're a gamer or you want the maximum GPU power for video editing with Final Cut or perhaps Davince Resolve, you might want to get 7600K + 580, with the caveat that not all of these will always be perfectly silent. Although in truth, the i7 + 580 might be preferred in some instances, despite the noise. If you have more limited needs though, like an amateur videographer using Final Cut or a more casual gamer, perhaps the 7600 + 575 might be fine, and you can put that extra cash towards more RAM or SSD.

And if you don't do any of that stuff, and your needs are light, then the 7500 + 570 is the appropriate choice, with the added bonus of having a "full guarantee" of an always silent machine.

 

[dsc888]

EugW, propower and smoothie. Wow! I have analysis paralysis trying to study everything that has been posted in the last 2 days. I'm sure all this data will help those on the fence decide which tier to order and whether or not the i7 warrants the extra cost. Now, I'm beginning to think that I should spend the extra $110 and step back up to the top tier i5 just for the GPU should some killer VR app comes along not too long from now. Geez. You guys are not making this easy!

 

[Chancha]

After using my i7 for 10 days I came to this conclusion:

The fan can be noisy more often than most people are used to, but it is bearable if not negligible (for my case).

Ordinary browsing, video watching, and file management:
fan always at 1200r-1400pm, except if a 4K+ video is played which is still rare.

Lightroom:
Library module culling at ~1600rpm, but once in develop module with RAW processing involved, all cores are called, after a few minutes fan is at 2000+ which starts becoming audible. Batch processing, preview generation, exporting etc of course fire up all hyper threading cores and fans at 2400 or so but the temp increases only gradually, probably after half an hour.

Gaming and video encoding:
Easily go into 2700rpm+ in under a minute, which is expected.

Throttling:
Starts happening after throwing unreasonable loads, I had to playback a 10bit HDR 4K video, capture HDMI video, playback a youtube 2K video, running 20 streams of BT, and have Civ VI running max setting at 1440p, all these at the same time to get clock down to 3.9Hz or so when the CPU average at 97 degrees. It seems the "trigger" of throttling is when 60W/100 degress is reached for prolonged period, say 30 seconds or so, then it got dragged down to 55W.

I have used thermally constrained Macs before, like the Mini 2012 and MBP 15" 2015, they both have noisy fans at max speed, these machines throttled even harder but somehow they had less fan noise, and their fans would kick in relatively later. I suspect this iMac is quite more efficient than the other Macs at cooling but at the expense of having the fans much more aggressive.

Now as to why I think this is a non-issue:
I am staying in Hong Kong where the average room temperature can easily reach 30 degrees in summer, which can be unbearable indoors. If the iMac is in a room being ran at heavy CPU load without turning on air conditioning it means I am not in the room to hear the noise. And then if I am sitting in front of the machine I definitely will leave the AC on, which "cancels out" probably half of the fans noise up to I'd say 2400rpm. In the odd events the fans have to be maxed at 2700-2800 rpm it means I am pushing the iMac to do a lot, I have no problems dealing with just a little noise if it means work are getting done at great speed.

When it gets to winter the room temperature go back down to 20 or even 15 degrees, then it effectively is the same as if I had the AC if not better, in terms of cool air supply for cooling intake. By then maybe the fan noise would be more audible without the AC noise canceling, but I am hoping the air intake is so much cooler then it means much more efficient cooling for the machine. I am thinking that if some users around the world living in cooler place may be the ones who are irritated by the noise issue the most, as their rooms are typically dead silent where most computers usually have no need to fire the fan up at all, whereas this iMac does it more often.
[doublepost=1499664808][/doublepost]

Thanks for the explanation. And that does make sense that the fans spin up for on demand previews. But it's a noise I never encountered with my 2012 rMBP or my 2010 MP so it's something I immediately noticed and didn't like. I have iStat and I saw the RPMs jump between 1800 and 2400 as I quickly thumbed through my 900+ RAWs. Again, it is normally a noiseless event on my laptop and low, constant hum with the MP.

The difference is the 5K screen. When Lightroom window is maximized on the 5K display, there is an enormous amount of data needed to be calculated rendered real time, if you do speed adjustments and/or local brushing then LR will struggle to keep up. Some other imaging apps seem to handle this better, especially Apple's Photos, but this falls into software optimization area. Also as others have explained, the LR develop module while generally slow, it actually uses the RAW data and avoid involving any compressed previews, which is fundamentally important for color critical task (try to color correct a sunset sky gradient in library module without banding). For workflow and professional reasons, often Adobe Lightroom is the "best" if not the only choice, for better or worse. So we just have to make do with its performance, but at least with this latest i7 iMac 2017 the bottleneck is no longer anywhere in the hardware, which means if and when Adobe decides to clean up the code mess, we may get better performance later.

 

[czacha]

The difference is the 5K screen. When Lightroom window is maximized on the 5K display, there is an enormous amount of data needed to be calculated rendered real time, if you do speed adjustments and/or local brushing then LR will struggle to keep up. Some other imaging apps seem to handle this better, especially Apple's Photos, but this falls into software optimization area. Also as others have explained, the LR develop module while generally slow, it actually uses the RAW data and avoid involving any compressed previews, which is fundamentally important for color critical task (try to color correct a sunset sky gradient in library module without banding). For workflow and professional reasons, often Adobe Lightroom is the "best" if not the only choice, for better or worse. So we just have to make do with its performance, but at least with this latest i7 iMac 2017 the bottleneck is no longer anywhere in the hardware, which means if and when Adobe decides to clean up the code mess, we may get better performance later.

Could you import to LR 100 or more RAW files and then generate 1:1 or smart previews for them and check how CPU behaves and what temperature and rpm it gets?

Lightroom is worst optimized app that exists at the moment I guess. You can acutally see it works slower even on 1080p when you change window size from half of the screen for full screen. I remember those videos on YT when people bought first 5K iMacs few years ago and performance with LR was horrible even with i7. Now there is much better GPU to operate high-res user interfece but still Adobe slows down Lightroom every new version it gets. Few of my friends started to use Capture One which I heard is much faster.

 

[Falcon80]

EugW, propower and smoothie. Wow! I have analysis paralysis trying to study everything that has been posted in the last 2 days. I'm sure all this data will help those on the fence decide which tier to order and whether or not the i7 warrants the extra cost. Now, I'm beginning to think that I should spend the extra $110 and step back up to the top tier i5 just for the GPU should some killer VR app comes along not too long from now. Geez. You guys are not making this easy!

If you are consuming VR content i.e user of VR apps, there should be no issue in using them with the lower end iMacs. VR is not something new. I believe the requirement for Radeon 580 is for VR content creation and probably also in a massive environment like what you saw in the keynote (The Star Wars environment).

 

[dsc888]

If you are consuming VR content i.e user of VR apps, there should be no issue in using them with the lower end iMacs. VR is not something new. I believe the requirement for Radeon 580 is for VR content creation and probably also in a massive environment like what you saw in the keynote (The Star Wars environment).

Thank you for the clarification! I learn something new each day

 

[user1234]

It's amazing how Capture One, Affinity Photo and some others manage to do heavy work without breaking a sweat, while Adobes poorly optimized apps struggle. Changing to the develop module shouldn't take 5-10 seconds and cause UI glitches on a 2013 rMBP. While I think my coming iMac will speed up Lightroom, I really hope Adobe get their **** together and rewrite their software for modern computers.

They should also add brightness and structure sliders in Lightroom. I miss them from my testing of Capture One.

 

[czacha]

I really hope Apple get their **** together and rewrite their software for modern computers.

You mean Adobe ?

 

[user1234]

You mean Adobe ?

I sure did. Thanks. I probably should have waited until I was more than half awake writing that post

 

[joema2]

....This video, bandwidth permitting on your end, got my fans to 2700 RPMs. I had it at the 8K setting in Chrome. 4K caused no such issue."

That is likely a new video encoded with Google's VP9 codec (similar to HEVC/H265). It won't even play at 4k or 8k in Safari which does not yet have VP9 support. If played at 8k in Chrome on a 2017 iMac it should not normally cause the fans to kick on -- IF Google wrote Chrome correctly to use Quick Sync decoding for VP9.

What you are seeing is likely a temporary situation isolated to a few 4k and 8k VP9 videos which Chrome is not efficiently decoding via Quick Sync. That same 2017 iMac i7 will probably play that 8k video smoothly and quietly as soon as Google updates Chrome. It's possible the upcoming macOS High Sierra update will update Safari to use Quick Sync decoding for VP9, which would also play that video smoothly and quietly.

So this is not a case of the 2017 iMac 27 i7 can't even play a video without the fans kicking on. It is an exotic edge case that will temporarily exist until Google and/or Apple update their software.

Background info: https://9to5mac.com/2017/01/12/youtube․com-no-longer-supports-4k-video-playback-in-safari/

 

[EugW]

After using my i7 for 10 days I came to this conclusion:

The fan can be noisy more often than most people are used to, but it is bearable if not negligible (for my case).

---

Starts happening after throwing unreasonable loads, I had to playback a 10bit HDR 4K video, capture HDMI video, playback a youtube 2K video, running 20 streams of BT, and have Civ VI running max setting at 1440p, all these at the same time to get clock down to 3.9Hz or so when the CPU average at 97 degrees. It seems the "trigger" of throttling is when 60W/100 degress is reached for prolonged period, say 30 seconds or so, then it got dragged down to 55W.

Thanks for the review.

Interesting that it throttles at 3.9 GHz. That just happens to be the exact normal multi-core clock speed of the i5-7600, albeit with HT on the i7.

I am not sure you need to throw all that load at the i7 to make it throttle. I suspect h.265 video encoding for a prolonged period would also make it throttle, esp. in a hot room.

That is likely a new video encoded with Google's VP9 codec (similar to HEVC/H265). It won't even play at 4k or 8k in Safari which does not yet have VP9 support. If played at 8k in Chrome on a 2017 iMac it should not normally cause the fans to kick on -- IF Google wrote Chrome correctly to use Quick Sync decoding for VP9.

I can't play the 8K video cleanly on my iMac i5-7600. CPU is not maxed out, but it's close at around 92%. I don't know why it doesn't hit 100%, but whatever the case, it won't play cleanly.

The 4K version plays cleanly with about 42% CPU utilization.

No fan speedup in either case with the i5-7600 though of course.

What you are seeing is likely a temporary situation isolated to a few 4k and 8k VP9 videos which Chrome is not efficiently decoding via Quick Sync. That same 2017 iMac i7 will probably play that 8k video smoothly and quietly as soon as Google updates Chrome. It's possible the upcoming macOS High Sierra update will update Safari to use Quick Sync decoding for VP9, which would also play that video smoothly and quietly.

So this is not a case of the 2017 iMac 27 i7 can't even play a video without the fans kicking on. It is an exotic edge case that will temporarily exist until Google and/or Apple update their software.

Background info: https://9to5mac.com/2017/01/12/youtube․com-no-longer-supports-4k-video-playback-in-safari/

I'm not sure how temporary this is. Hopefully it is temporary, but I'm not counting on this changing in the near term.

 

[dsc888]

That is likely a new video encoded with Google's VP9 codec (similar to HEVC/H265). It won't even play at 4k or 8k in Safari which does not yet have VP9 support. If played at 8k in Chrome on a 2017 iMac it should not normally cause the fans to kick on -- IF Google wrote Chrome correctly to use Quick Sync decoding for VP9.

What you are seeing is likely a temporary situation isolated to a few 4k and 8k VP9 videos which Chrome is not efficiently decoding via Quick Sync. That same 2017 iMac i7 will probably play that 8k video smoothly and quietly as soon as Google updates Chrome. It's possible the upcoming macOS High Sierra update will update Safari to use Quick Sync decoding for VP9, which would also play that video smoothly and quietly.

So this is not a case of the 2017 iMac 27 i7 can't even play a video without the fans kicking on. It is an exotic edge case that will temporarily exist until Google and/or Apple update their software.

Background info: https://9to5mac.com/2017/01/12/youtube․com-no-longer-supports-4k-video-playback-in-safari/

Thanks for the write up. Yeah. I use Chrome for 4K videos exclusively and can't wait till Safari can play them along with 8K videos again. The 5K screen just screams out for super high resolution media. Let's hope that things are well sorted out by the time High Sierra is released to the public.
[doublepost=1499711139][/doublepost]

If you are consuming VR content i.e user of VR apps, there should be no issue in using them with the lower end iMacs. VR is not something new. I believe the requirement for Radeon 580 is for VR content creation and probably also in a massive environment like what you saw in the keynote (The Star Wars environment).

I agree with you. Apple is all about the experience. All the new iMacs probably can run VR but it's how smooth it runs that might have made them officially state that only the 580 is VR ready.

 

[DisMyMac]

The 5K screen just screams out for super high resolution media.

Most people scale them to 1440p. Doesn't that make it all pointless?

 

[mollyc]

I am primarily a LR and PS user. The only real video I might do is a 15 minute slideshow export out of LR. I am a still photographer. I still have never gotten a very good answer as to whether PS and LR use the hyper threading available in the i7s (and I will be honest in that I don't even really know what that means, but that for certain workflows it would be important). I currently use a 2012 iMac that has an i7 in it. Would I need to stick with the i7 in the 2017 iMac, or is one of the i5s okay, and if so, which one?

 

[EugW]

I personally wouldn’t know, but many people are saying you really do want the 580 for even just VR consumption, not just VR development.

ie. Some say the 580 should be considered the entry point for VR.

 

[EnderBeta]

What the point of having the top of the line iMac having the worse sound levels. People buy the i7 to increase the usable lifetime of the iMac.

I can confirm the Late 2015 i7 with the 395X graphics does the same thing under load.

This isn't something to be worried about. As long as the temperatures remain at the Intel recommended levels the processor will be fine.

The reason for the heat is that in the case of the processors Apple chooses the i7 has more cores which is more heat compounded by the fact that each core is faster which in turn generates more heat.

At least it sounds like white noise. It could be worse and sound like the wind tunnels Intel sold with their P4 Xeons 533FSB. Those things where shriekers.

 

[MacDevil7334]

I am primarily a LR and PS user. The only real video I might do is a 15 minute slideshow export out of LR. I am a still photographer. I still have never gotten a very good answer as to whether PS and LR use the hyper threading available in the i7s (and I will be honest in that I don't even really know what that means, but that for certain workflows it would be important). I currently use a 2012 iMac that has an i7 in it. Would I need to stick with the i7 in the 2017 iMac, or is one of the i5s okay, and if so, which one?

I do pretty much the same things as you and went for the mid-tier i5/Radeon 575 model. It arrived last Thursday and so far it has been great for Lightroom work. Haven't had a chance to run Photoshop yet. I'm switching from a 15" rMBP mid 2014, so I can't compare to the speed of previous iMacs. I will say it is definitely faster than my laptop and seems to be more than capable of handling anything I've thrown at it so far. Also, editing on the huge 27" screen is amazing coming from a 15" MBP.

There is definitely a push on these forums to get the top end i7 model just because it is "the best". But, unless you do video editing, VR work, or heavy gaming, the i7 is probably overkill. The i7 also runs much hotter than the i5 and users are reporting increased fan noise. I think the i5 will be fine for your needs. Probably any of them will be fine but the mid-tier model seems to be about the sweet spot in terms of performance and heat. The top end 3.8 GHz i5 would probably be about as quiet, but it does has the potential to run much hotter than the 3.5 GHz chip. Really, whatever you do, get an SSD over a Fusion drive before you even think about upgrading the processor.

 

[EugW]

Really, whatever you do, get an SSD over a Fusion drive before you even think about upgrading the processor.

Yes, I'd take SSD over a processor upgrade any day.

 

[glazball]

There is definitely a push on these forums to get the top end i7 model just because it is "the best". But, unless you do video editing, VR work, or heavy gaming, the i7 is probably overkill. The i7 also runs much hotter than the i5 and users are reporting increased fan noise. I think the i5 will be fine for your needs. Probably any of them will be fine but the mid-tier model seems to be about the sweet spot in terms of performance and heat. The top end 3.8 GHz i5 would probably be about as quiet, but it does has the potential to run much hotter than the 3.5 GHz chip. Really, whatever you do, get an SSD over a Fusion drive before you even think about upgrading the processor.

Admittedly, I'm new to the forums but I'm quite puzzled by the fact that everyone seems to want a silent computer. Sure, silence is preferred, but fan noise really should be the least of the average user's concerns. (Very few people NEED a completely silent computer). After all, if you are really that worried about fan noise, maybe an all-in-one computer is not right for you (by "you" I mean the general reader).

 

[EugW]

Admittedly, I'm new to the forums but I'm quite puzzled by the fact that everyone seems to want a silent computer. Sure, silence is preferred, but fan noise really should be the least of the average user's concerns. (Very few people NEED a completely silent computer). After all, if you are really that worried about fan noise, maybe an all-in-one computer is not right for you (by "you" I mean the general reader).

Unfortunately, Apple doesn't sell any reasonably priced desktops with higher end performance with a separate monitor.

You have the Mac mini, but that's basically just an ancient model laptop without a built in screen or keyboard, and then you have the Mac Pro which is also an ancient model machine, but which is very expensive.

The best value line for many of us is the iMac, which is an all-in-one. And many of us like quiet computers. I figured the i7 would ramp up in noise with heavy usage and I tried to convince myself that was acceptable. And it is acceptable, for some people. But for me, I eventually decided I didn't want that and was willing to give up performance to get that quiet computer. I returned my i7 iMac, and I'm happier without it. I saved a few hundred bucks in the process too, so that's a bonus.

 

[Falcon80]

Admittedly, I'm new to the forums but I'm quite puzzled by the fact that everyone seems to want a silent computer. Sure, silence is preferred, but fan noise really should be the least of the average user's concerns. (Very few people NEED a completely silent computer). After all, if you are really that worried about fan noise, maybe an all-in-one computer is not right for you (by "you" I mean the general reader).

The fan noise is caused by the high heat. That is what I am truly concerned as I am not working in especially cooling environment. If the fan noise is due to multiple fans inside the iMac trying keep it cool at all time, I am totally fine with it.

 

[Falcon80]

I personally wouldn’t know, but many people are saying you really do want the 580 for even just VR consumption, not just VR development.

ie. Some say the 580 should be considered the entry point for VR.

If this is true, Apple is taking a huge step backward by making their VR technology not available to mainstream. I have been working with VR related projects like Oculus Rift since about 4 years ago and my 2012 MacBook Pro at my workplace works just fine.

 

[EugW]

If this is true, Apple is taking a huge step backward by making their VR technology not available to mainstream. I have been working with VR related projects like Oculus Rift since about 4 years ago and my 2012 MacBook Pro at my workplace works just fine.

Again, I don't know VR, but I will point out that the 580 is mainstream already in 2017, and Apple VR won't really be a thing until 2018. In 2018, we will have 6-core mainstream i5 and i7 CPUs in non-Pro iMacs, and GPUs to match, possibly on a TSMC 10 nm process. I wouldn't be surprised if in 2018, the 580's performance is mid-tier or lower for the 27" iMac.

As you already know, the 570 entry level is actually more powerful than the top CTO tier of the last generation of iMac GPUs (M395X).