Yep, about a 25% difference. But just to clarify since I didn't see your earlier post - the i5 and i7 you did this same encode on had the exact same clock speed and ram and all that?
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The new iMac is a lot noisier!
- Thread starter Darajavahus
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Yep, about a 25% difference. But just to clarify since I didn't see your earlier post - the i5 and i7 you did this same encode on had the exact same clock speed and ram and all that?
No. you can't get one with the same clock speed, unless you just turn off HT in the i7.
It was the i7 7700K vs the i5 7600. Come to think of it, for this clip, it was another person doing the encode, but we had the exact same settings and the exact same clip. (I did have the 7700K for a week, but was doing testing with different clips.)
The i7 7700K in 4-core (8-thread) mode runs at up to 4.4 GHz. The i5 7600 runs at 3.9 GHz in 4-core mode. That represents a 13% difference in clock speed. So the other 12% difference would be due to HT.
I think for software 3D rendering (Cinebench) the difference due to HT is around 20% though.
The 2017 iMac i7 is no louder than the 2015 or 2013 -- I have one of each, and I have the 2015 and 2017 models side-by-side on my desk right now. Despite the recent high visibility of this topic, and despite the thread title proclaiming "the new iMac is a lot noisier!", there is nothing new or different in the 2017 i7 model. It is NOT noisier than other i7 iMacs back to 2013.
What *has* changed is you can now get a 3.8Ghz i5 iMac 27 with the top-spec GPU and which is faster in CPU and GPU terms than the top-spec 2013 i7 model, yet it will be significantly quieter under high load. Why even get the i7 model? Because it's still considerably faster than the top i5 -- 30% faster in Geekbench multicore, and maybe even more in certain workloads that leverage hyperthreading.
The 2017 i7 iMac only creates more fan noise under certain conditions, where you normally really need the extra performance. The advantages of hyperthreading are not "dubious at best", but in some workloads I've actually measured can improve performance by 30% over having it disabled. There are workloads where the 4.2Ghz i7 is 40% faster than the 3.8Ghz i5 -- 11% from the CPU clock and 30% from hyperthreading. However these are difficult to identify ahead of time without actual testing, and don't typify all cases or even the common case -- but they do exist.
As mentioned before I was hoping the 2017 i7 would behave like my 2010 i7. The 2010 can get loud too, but it takes a lot, lot longer to get to that loudness. What that meant was that for a lot of short clips (eg. short birthday videos, etc.), it'd stay relatively quiet during the encode.
In contrast, the 2017 i7 pretty much always will kick the fan into high gear with pretty much anything I encode. Granted, this is really just a nuisance, and as you can probably guess, I don't actually need i7 speed most of the time, but it would have been a nice bonus to have, had the new i7 behaved like my old 2010 i7.
Yes, Intel pretty much messed up with the 7700K thermals. The fact that they said not to even overclock it and it can instantly spike 30 Celsius just opening a website is crazy.
I hope the latest AMD processors, while maybe not as good as Intel in some benchmarks, make Intel work a bit more on these issues. AMD is out of the blue getting MUCH better after SO LONG of Intel being really the only good choice.
This is my fan setup on my cranky old PC: 3 140mm Noctua fans (two on the noctua D15s, one on rear), and two 200mm fans (one front, one top). Think the iMac will be more noticeable since the fan is smaller/higher pitched? my PC is basically on full blast all the time, but it's a constant low "WHOOSH"
Wow. So it definitely looks like this isn't just a few oversensitive people on Macrumors. The i7 does seem to have a problem. Glad more than ever I chose the i5 model.
https://www.extremetech.com/computi...g-issue-cluelessly-suggests-stop-overclocking
The people complaining about the iMac noise are running long-duration CPU and/or GPU-intensive multithreaded tasks, some including command-line synthetic CPU stress.
For one hour if you concurrently run Prime95 with in-place large FFTs, while also running the Furmark GPU burn-in test, does your PC stay at the same "constant low" noise level? I have a similar PC with similar cooling as yours, and mine does not stay quiet under that level of stress.
[doublepost=1504901104][/doublepost]
That article has nothing to do with what people are reporting here. It is exclusively about over-clocking, which you obviously can't do on a Mac. There is no major difference in iMac noise or heat between the 2013, 2015 and 2017 i7 models. Of those three the 2017 i7 model produces the least heat overall. It seems the 2014 i7 model produced a little more total heat; all of this is shown on Apple's own specs: https://support.apple.com/en-us/HT201918
There is no "problem" with the i7-7700K that affects the 2017 iMac 27 heat or noise any more than the i7 CPUs of prior models did back to 2013. This high-CPU noise behavior on the 2017 iMac has been here for at least four years and a few people just recently noticed it.
Even though the current iMac i7 noise behavior has been mostly unchanged since 2013 (except maybe the 2014 model which was possibly worse), the 3.8Ghz i5 now enables a lower-noise option for people who frequently run high-CPU tasks, yet it maintains pretty good CPU performance. That is the only new thing, but it's incorrectly being described as "The new iMac is a lot noisier", as in this thread title.
No, that model has a bad issue with heat so intel said not to even over clock it and they stated that it can spike 30 degrees celsius just opening a website. So yes, it does have to do with the Mac because that thing is HOT HOT HOT. What needs to run to cool something HOT to where you can't even overclock it without severe issues? FANS!!! This is why previous models were quieter than this years models. And people are mad that the K model specifically made for overclocking is recommended to not overclock due to heat.
That's a stretch. From the article:
You always need to be aware of temperatures when overclocking a chip, and this is where some owners of the 7700s are running into issues.
In this post someone says no problems (after a day of use) and EugW responds, "The i7 in the 21.5" is the 7700, which is 65 Watt TDP chip, and in real world testing it not surprisingly will usually run cooler than the 91 Watt TDP 7600K. It's too bad this is not available in the 27", because it's actually faster than the 7600K."
Of course, you won't have the same storage options (no 2Tb/3Tb Fusion drive options) and since the RAM is soldered you need to choose it in advance, and pay through the nose while doing so ($600 for 32Gb RAM upgrade? pshaw).
I honestly wouldn't do that to my own machine for the first year (or three, I I bought Applecare) because if any problem arises and apple think it's possible your non-user-installable work was related to the problem they'll say you voided your warranty.
Prices favor 27" overall. 512Gb SSD in the low-end & mid-priced 27" is $300, and it's $200 in the high-end model. 512Gb SSD isn't even available in the low-end 21" model, and it's $400 in the mid-priced and $300 in the high-end 21" model. Considering the much lower price of (easily, legally, user installable) RAM and the lower price of the 27" models, plus the better GPUs (and an awesome monitor), I really don't recommend the 21" unless it's a matter of budget.
As for the GPUs, take a look. In the 21" it's either Intel Iris Plus Graphics 640, Radeon 555 or Radeon 560. The graphic cards in the 27" are much better: Radeon 570/575/580 with 2x-4x as much video RAM.
I really don't see the value in downgrading to 21" just to take that i7.
Fan noise. according to benchmarks even the 21"i7 iMac kicks the crap out of the 6 core Mac Pro costing 300 more refurbished and still needing a monitor.
So 600 more with a mid level 4k monitor. It's 3rd in single core geekbench scores and just below 8 core and 27" i7 on multi-core. Seems like a decent trade off.
So 600 more with a mid level 4k monitor. It's 3rd in single core geekbench scores and just below 8 core and 27" i7 on multi-core. Seems like a decent trade off.
[doublepost=1505022613][/doublepost]WRONG.
There is CLEARLY a problem. Enjoy your i7 crashing and burning in a year or so.
I am getting the 7600/575 and will use an eGPU in 2018-2019.
Can you be more specific (and less emphatic) about what he said that was incorrect?
For some users overclocking the 7700k, I agree. It said so in that article.
Yeah, that's not happening and even if something like it ever did that's what AppleCare is for.
Good for you.
Well, I hope you will be as pleased with it as I am with my 7700K and 580 GPU (neither of which overheats nor gets loud).
As is always the case, these things all depend on one's personal needs and usage.
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I own and use the 2013 i7 iMac 27, 2015 i7 iMac 27 and 2017 i7 iMac 27. These are all used for professional video editing and often spend hours per day in a high-CPU state transcoding or editing video. The previous models back to 2013 ARE NOT quieter -- overall they are about the same. There no major heat problem with the 4.2Ghz i7-7700K in the 2017 iMac, at least nothing different than the models back to 2013. That posted article on overclocking the 4.2Ghz i7 has nothing to do with an iMac.
Seriously this years model is no louder than the 2015 i7 iMac, and I had a 2015 i7 model. This years 7700k although hot is running better than the Sky Lake 6700k under load. Quote below is from a site I'll link to at the end..
"heavy CPU usage like video transcoding would inhibit the 2015 iMac from boosting. The new Kaby Lake i7 processor is capable of handling that load while supporting Turbo boosts up to 200MHz. The architecture upgrade not only offers improvements to power efficiency, but also a faster overall clock speed under full load."
Now the 2017 i7 its not perfect and will throttle under 100% load for a prolonged period, but it maintains its base clock speed unlike the 2015 model it appears. Also the M395X was not a huge leap in performance from the 2014 M295X and this year there is a considerable upgrade in performance with the 580 over the previous generations top of the line GPU's.
If you came from a older mac before the change to single fan cooling yes it may appear louder, but as has been said already the 2017 iMac is not the nosiest, in all honestly that dubious honour may go to the 2014 model.
http://appleinsider.com/articles/17/06/30/showdown-apples-2015-imac-vs-2017-imac
There are 33 pages or so to this thread for a reason. The i7 is flawed. There is no denying it.
Oh boy! This is a very good point! I don`t even think about this but this could me a very good solution for me:
Get the i5 with "only" the 575. And if I plan to game in a few years I will buy an external GPU.
Question: What`s with the stronger i5 and the 580? Is this CPU also getting hot and loud so fast?
Much of the 33 pages are based on an incorrect OP statement "it's noisier than before" and incorrect thread title. The 2017 i7 iMac is NOT noisier than before -- it's faster than before at about the same noise level. In some cases such as transcoding in FCPX from H264 to proxy, it is TWICE as fast as the 2015 model. This is probably due to the improved Quick Sync logic in the i7-7700K. Most of the reason for the 33 pages was well described by Albert Einstein's statement about only two things being infinite in the universe.
EugW has done a valuable service by showing how 3.8Ghz i5 is now a viable option in many CPU-intensive applications. It has about the same multicore performance and much better GPU performance than the top-spec 2013 iMac 27, yet is cooler and quieter. However some people cannot figure this out and believe the 2017 i7 iMac is somehow flawed or worse in terms of noise and heat than the 2013, 2014, or 2015 i7 models. It is definitely not. For the most part nothing has changed in this regard.
In fact the 2017 i7 model is definitely better in terms of noise and heat than the 2014 model. Ironically this thread isn't about the 2014 model -- if anything THAT one deserved a thread like this.