iMac 2019 - i5 9th gen vs i9

LLA said:

My question is three-fold...

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...and the answers could be manifold, I'm afraid to say. Which CPU and GPU to choose is not easy to be answered, and depends a lot on your intended use and on how much you're willing to spend on the machine. Over the course of the last weeks, there have been several threads discussing whether one should get the i5-9600K or the i9 processor in their 2019 iMac, and whether to go with the 580X or Vega 48 GPU. I'd recommend reading through some of them (there are some who specifically ask which iMac to get for photo editing) to form an opinion and then ask any question that's left.

I am debating on whether to buy the iMac i5 9th gen or the i9. I am a using it for Photoshop, InDesign, Illustrator, and eventually After Effects. I know that the i5 can handle my needs, but wondering if I need to be doing things like 4k video editing and such to warrant the i9 making a difference. In other words, will the increase in the advertised speediness of the i9 be noticeable for my purposes?

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The increase in speed will probably be most noticeable when exporting photos/videos. But the newest software makes use of the GPU too for processing, so you will also have to decide between the 580X and Vega.

Take a look at this video and maybe watch some more of his (Max Yuryev's) videos. He tests new Macs with focus on video editing and might give you some help in choosing.

Then maybe have a look at this thread where I posted my findings when doing some exporting tests with the i9/Vega combination. After these tests, I think the i5 might be powerful enough for photo editing, with the i9 having an advantage when using several apps in parallel. One thing you have to be aware of is that the 5K iMac display alone needs a lot of processing power just to draw all these pixels, one thing I hadn't been expecting (resulting in a lag when drawing masks, see the referenced thread for more on this). Depending from which machine you upgrade, this might come as a surprise-I came from a 2011 MBP which wasn't overly slow at photo editing and was surprised the workflow wasn't that much snappier on the new machine, until I realized that to drive that beautiful 27" display it has to lug around over 6 times the pixels of the old one. Conclusion: it might be advisable to get the fastest machine you can get, that 5K display alone needs some processing power. But then, even the "base" 27" model with the 3.0GHz i5-8500 and the 570X will be a great machine for photo editing (choosing a lot of RAM and an SSD is a wise choice, but you've done that already).

You see, the "i5 or i9" and "580X or Vega" questions are not easy to answer...

Also, I was talking to Apple yesterday and they were saying that it's not just the speed, but the efficiency/other ways the i9 chip works, which makes it better and have more longevity. True?

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I don't know about longevity, but for the i9 I can say it's pretty efficient, only ramps up the power when it needs to. See e.g. this post where you can see that idling, the CPU goes down to 1.4GHz, using 2-3W of power, and ramps up at the end where I start drawing a mask. With the i5-9600K being of the same generation, I would suppose it's equally efficient.

Lastly, they were saying that heat is the enemy of computers and their components.

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I'm surprised Apple would admit that.

I have read that the i9 gets hot (they had no comment on that), but wondering if that is only when being pushed to its limit, or if it's just a hot chip in general.

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Both the i9 and the i5-9600K have a TDP of 95W, so under continued load, they should get equally hot in the iMac, as they're restricted to stay within this value by Apple (in a PC environment, you can implement more powerful cooling, then those processors can draw over 200W under load).

As you can see in the post referenced above, idling, the CPU temp of the i9 stays around 40°C, with light work, it can get up around 50°C. Under full load, both CPUs will get up to around 90°C, and be kept there by a combination of fans and throttling. However, with its 16 threads, the i9 will finish the task faster (if the software utilizes more than 6 threads) and cool down again sooner than the i5, returning to 40-50°C.

LLA said:

Photoshop, InDesign, Illustrator, and eventually After Effects. I know that the i5 can handle my needs, but wondering if I need to be doing things like 4k video editing and such to warrant the i9 making a difference.

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Short answer: Yes. Absolutely.

If you get the i9, you won't be staring at the i5 and wondering, How much faster would this be if I bought the i9? I'm serious.

LLA said:

Lastly, they were saying that heat is the enemy of computers and their components

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The differences between the i9 iMac and the iMac Pro are not so clear cut performance wise but...

The iMP runs cooler and comes with 8-Core Xeon, 32GB RAM, 1TB SSD, has two more TB3 ports and a Vega 56 GPU in its base configuration, $4,249 in the Refurb Store is the same price as a loaded i9. Food for thought.

The new iMac is hurting iMP sales and the Refurb Store prices are Apple's way of giving you a better price without actually lowering the official price. If these were actual Refurbs, they would run out. The BTOs do now and then and the base model never does.
https://www.apple.com/shop/refurbished/mac/imac-pro

I seriously considered the i9 before buying the iMP.
[doublepost=1558742239][/doublepost]What he says:

Bohemien said:

One thing you have to be aware of is that the 5K iMac display alone needs a lot of processing power just to draw all these pixels,

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For your uses, the Vega 48 (i9 option), Vega 56 (iMP base) or Vega 64 (iMP option) should be given serious consideration. The 580/580x pales by comparison.

I couldn't tell if you're a serious hobbyist or a working pro. If a hobbyist, anything you get will be good... but better is better, right? At some point, you do draw a line in the budget/performance equation.

If you're a working pro, it's different. When Time saved=money earned, the more horsepower in your iMac the better. Those BTO iMPs in the Refurb store aren't so expensive anymore.

mikehalloran said:

Short answer: Yes. Absolutely.

The differences between the i9 iMac and the iMac Pro are not so clear cut performance wise but...

The iMP runs cooler and comes with 32GB RAM, 1TB SSD, has two more TB3 ports and a Vega 56 GPU in its base configuration, $4,249 in the Refurb Store is the same price as a loaded i9. Food for thought.

The new iMac is hurting iMP sales and the Refurb Store prices are Apple's way of giving you a better price without actually lowering the official price. If these were actual Refurbs, they would run out. The BTOs do now and then and the base model never does.
https://www.apple.com/shop/refurbished/mac/imac-pro
.

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Don’t forget the 10gbe Ethernet built in. If you do a lot of work with a NAS, this will allow you to keep all your photos and footage in a closet and not hear the drives.

I’m waiting for the WDC in June to see if they come out with anything new.

But a refurb iMac pro is awfully tempting.

mdelrossi said:

Don’t forget the 10gbe Ethernet built in. If you do a lot of work with a NAS, this will allow you to keep all your photos and footage in a closet and not hear the drives.

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True but that's not the best part of 10G Ethernet.

Did you see those videos released the day of the Mini 2018? These showed stacks of 5–20 Minis sometimes with an iMP all linked together to render a huge graphics or animation file — what some studios do every day. This is done through the T2 chips via 10G Ethernet. An Apple rep I spoke with says that the 1G Minis can't do this. Although that's $18k–$60k of Mac in those arrays, there are $150k 56 core Windows boxes designed to crunch those same files (in case anyone is still wondering what target the next Mac Pro is aiming at).

Missed that video. Also didn’t know the mini had 10gbe. Hmm....

EDIT: BTO, and soldered Ssd. Never mind.

You'll eventually appreciate the i9 during export.

LLA said:

are you saying that the i5 and i9 will both get just as warm, whether under full load or not/just in general? Asking because one of the reasons I was against the i9 was because I thought it would be a generally hotter CPU. I don't want a CPU that is going to heat up the other elements inside the iMac.

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If you want the "coolest" CPU, that would be the i5-8500 and i5-8600 processors used in the entry and mid-level 27" iMacs, both with a TDP of 65W. That said, AFAIK every Mac in the last 8 years will get up to around 90° C under load, and then the power management keeps it there (with throttling the CPU speed and ramping up the fans). If there are any differences regarding temperature between the i5-9600K and i9, watch out if you find information on this in the various threads here or the video reviews. I think someone wrote the i5 stays a bit (like 5 degrees) cooler than the i9, but if yes, I read that weeks ago and can remember it completely wrong.

What I meant to say above was this: say you want to export 100 RAW files from any RAW editor. Say the i5 machine will finish the task in 5 minutes, the i9 in 4 minutes (fictitious numbers, just for the sake of the example!). Then BOTH machines will get up to 90°C during the export, but the i9 will start cooling down again after 4 minutes, the i5 machine staying at 90°C one minute longer.

But really: I haven't heard of any issues with computers due to CPU/GPUs getting hot, forget that thing the Apple rep said, sounds like he wanted to sell you on the more expensive machine IMHO. (Somebody correct me if I'm wrong on this!)

I'd recommend basing your decision whether to go with the top-spec i5 or i9 CPU on price vs. performance questions, not on hypothetically having a "warmer" CPU. The only reason to worry about heat would be whether the fans would ramp up faster on one machine against the other (for me), and so far my i9 iMac runs nice and quiet, but then I haven't read anything about the i5 version being louder. (That was a problem with the 2017 line, where the top-spec i7 machine would ramp up the fans to max. pretty often, apparently.)

This kinda answers it.

Temperature wise, this gives us an idea.

I ran Cinebench on my 27" i5 9600k/Vega48/16GB RAM/1TB SSD iMac back to back about 5 times, and the highest temp was 95C and averaged about 90C. The GPU PECI never got about 71C. And the Frequency seemed to just lock into a pretty constant 4.1GHZ.

Cinebench scores were all around 2500. I ran Geekbench once and got 5957 single-core and 23755 multi-core.

spiderpumpkin said:

I ran Cinebench on my 27" i5 9600k/Vega48/16GB RAM/1TB SSD iMac back to back about 5 times, and the highest temp was 95c and averaged about 90c. The GPU PECI never got about 71c. And the Frequency seemed to just lock into a pretty constant 4.1GHZ.

Cinebench scores were all around 2500. I ran Geekbench once and got 5957 single-core and 23755 multi-core.

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Nice. Did your fans kick in or was it more or less silent?

Whackintosh said:

Nice. Did your fans kick in or was it more or less silent?

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Idle temp of iMac seems to be at around 40C on average. Fans run at a constant 1200rpm. Fans ramped up to about 1600 but not until about the 4th Cinebench test.

The previous iMac, that I returned, was a 27" i9 9900K/580X/16GB RAM/512GB SSD. That one seemed to get up to and average 100C a lot when running full blast, and I don't think the Frequency was very constant and I recall being lower than 4.1GHZ average I get from i5. The 580X would run at like 80-90C on Cinebench if I recall correctly.

Just ran Heaven benchmark and the fans ramped up to 2200rpm and GPU chip averaged about 90C. CPU averaged 60C. Scored 1906 with average of 76fps.

When I had the i9 9900K 580X iMac the CPU seemed to average 100C+ under heavy load and I don't recall the CPU frequency locking in to a constant rate.

Now, the i5 9600K Vega 48 iMac seems to never easily lock into a 4.3GHZ frequency under heavy load and the temps only average about 90C when doing so. I haven't seen the i5 go over 95C and going that hi seems to be a rare occurence.

I'd sum up:

i9/580X (hottest) - i9 under load in the lower range

i9/Vega 48 ~ i5/580X - i9 under load in the middle range

i5/Vega 48 (coolest) - i5 under load in the top range

The i9 gets the job done faster regardless due to the extra cores.

One thing to note is the thermal design of the iMac may limit the i9 from maintaining the high CPU frequencies that it should be able to attain.

Another thing to consider is that the Apple recommends disabling the hyperthreading of the i9 due to security vulnerabilities like Zombieload. Right now disabling hyper threading is optional but maybe in the future they will just make that a default fix.

If you can afford it go for it... from the spec you describe above its only 10% more expensive.

In the previous gen 2017 I went for the base simply because the mid tier was within 5% and the hyperthreaded CPUs throttled to the point that they performed very similarly under the same intense load because the i5s can keep their base clock speeds and turbo whereas the 7700k couldn't so the 25% benchmark difference in real life was minimal.

With this gen the i9 is a great option it seems like although it gets hot its not the same as the 7700k and you get an 8 core chip.

Single core they are similar and multi 22k vs 33k the i9 is roughly 43% faster... if you are doing multithreaded tasks there is a stark difference. The cost difference like I said is 10% but your getting 43% faster multithreaded power if that makes it easy to justify the cost.

That being said 22k is nothing to put down. At the end of the day a 10 min video export may take 30sec to 1 min longer. At the end of the day it depends whether you have clients desperate for work that justifys the extra minute.

My clients dont and when im rendering I make a cup of tea come back and its done and dont worry.

People focus too much on these things, look at what you do any make a decision that way.

For me I bought a 10 month old 2017 base iMac for £1100 with applecare and the trackpad preowned on FB for sale which was £2200 list. I put 32gbs of ram in it for £165, a samsung X5 for £200 and an OWC Thunderbay 6 for £600.

All in £2065...

The additions made my disk speed 2000 writes 2500 reads, 5500 single 16000 multi. Works for me and theres a lot of machine there for the money.

Im a photographer and videographer and turn out thousands of images a week 2 to 3 vid a month... its been spot on so far.

I really wrestled with what configuration to buy. I ultimately went for the i5 580x. To me it depends on your budget and how much any individual will use the additional speed of the i9. For someone like a professional video editor, the i9 would seem a no brainer. A professional photographer who might be importing large numbers of raw files and then exporting large numbers of tiffs or psd files. An audio engineer. Someone frequently doing cpu intensive analysis of large databases, etc. FWIW, I'm a statistician and my work computer is a Dell with some variant of a quad core i7. I can make it groan once in a while if I have to do something like generating bootstrapped confidence intervals for some kind of multi-level model that requires numerical integration. But even that computer is absolutely fine for the vast majority of my statistical analysis. I'm a hobbyist photographer. After a vacation I might import large numbers of raw files. But I'm not doing that daily, so even if I doubled the import time it's really not of significant consequence to me. Exporting image files is an area where multithreading seems to offer tangible benefit. But I'm usually only a few files at any one time. I use PS sometimes, but almost never doing really layer heavy kinds of things that are really taxing on cpu or gpu. I'm the MAJOR BOTTLENECK in my work flow. I'm not a gamer. My video editing is pretty limited. Other things I do on my personal computer are pretty routine. So ultimately I just decided the i9 and/or Vega 48 were overkill for my needs. I could end up regretting that decision 5 years down the line. Or, we could be looking at really different platforms in which even a current i9 seems somewhat obsolete. I can't compare the i5 to i9. I just felt the i5 was a better value for MY needs. I am very happy with. For the same price, I'd prefer the i9.

Exactly.

Lets be honest the base line is now a 6 core... were not talking slow anything anymore. 10 years ago dual core cpus that ran like 1000 single and 3000 multi these machines are like 1000% faster.

It also depends on the media you are editing, if your editing 30fps 1080 H264 or older stills like 10-18mp Full frame or crop sensor cameras the base machines will absolutely fly. If you use high end stuff like 50mp full frame cameras and large format 4k H265 then the faster machines are worth buying.

If your not doing these things on the daily is it worth it... probably not, its not a huge difference with the UI the performance is not day and night. Multi is all about number crunching import/export. The average user exporting a 10-20 min video once and a while and editing a few dozen images it really isnt going to be a big deal.

You also have a bear in mind what these performance gains actually mean. Most of the adobe suite is not particularly well optimised, single core is still really important in this aspect. Quick bursts of turbo boost where you are making changes through the UI, exposure etc. Multi core performance currently doesn't do much for the actual experience of editing through the UI in lightroom for example. This is where IMO the time gains could be had if the UI is slow its a frustrating experience.

Especially lightroom imports exports can vary massively machine to machine dependent on hardware but the actual develop module performance is based on single core performance. In this respect the base 2017 27" iMac feels almost exactly the same as the base line iMac pro as the scores are about the same 5000 range.... Whereas the iMac pro is probably twice the speed for import export.

I read a lot of threads of people being disappointed with performance, amateurs buying £5000 iMac pros and finding certain tasks crawling etc...

For example I shot a wedding through the week imported 600 select images from 2x 5DMKIV and 1x 5DSR roughly 35gbs rendered 1:1 and made smart previews it took about 16 mins which isnt bad on a base 2017 27" iMac. Even if it was twice as quick and I shot 2 weddings a week it would save me 14 mins.... literally one tea break. To me its the performance of the UI is where the bottleneck is. For example every time you zoom into an image in lightroom and it take 3 seconds to render the 100% preview in for 600 images you are literally sitting for 30 minutes waiting through your workflow. If you work 8 hours per day thats 1/16th of your time, thats just one aspect. Say you do 60 weddings a year thats 30 hours per year... its a weeks work just waiting for a 100% preview. That time say £250 per day is worth £1250...

If I go back to the analogy above of the iMac pro vs baseline. If it takes 16 mins to import 600 raw images then 40 mins to export roughly 55 mins. To actually get through and edit all those images you might spend 3 8 hours days - 24 hours of work.

For me the import/export isnt the big deal its 1/24th of the time. Its efficiencies of actually editing the images.

When it comes to rendering, for me I can still be productive answering email etc. To export those images at 300dpi at full resolution will take 40 mins but I just leave it, its not a deal breaker.

If your exporting 10-15 images it take no time at all so...

Other programs like Final Cut are really well optimised so again the likelihood is your experience will be good, premier not so much.

Like I said people get really hung up on the time aspect and its really overblown unless you are working professionally where this time really adds up over a month for example... A lot of jobs in the creative industry come down to money and if your being paid £250 per day and an hour of that is rendering its where you can cut time for a small upfront cost and pass it directly onto the client meaning its more likely of taking you on and repeat business.

Its also your own time... if your are a well known successful professional if you can get the job done quicker its more time out in the field doing your own projects or more importantly time with the family... it also means you can make higher margins etc.

spiderpumpkin said:

Another thing to consider is that the Apple recommends disabling the hyperthreading of the i9 due to security vulnerabilities like Zombieload. Right now disabling hyper threading is optional but maybe in the future they will just make that a default fix.

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I wouldn't worry too much about this, it's a bit too exaggerated. No one needs to completely disable HT unless you're doing sensitive works which I doubt anyone does on a software encryption only machine (this is where the T2 shines).

spiderpumpkin said:

One thing to note is the thermal design of the iMac may limit the i9 from maintaining the high CPU frequencies that it should be able to attain.

Another thing to consider is that the Apple recommends disabling the hyperthreading of the i9 due to security vulnerabilities like Zombieload. Right now disabling hyper threading is optional but maybe in the future they will just make that a default fix.

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Max load on my i9 on just a couple cores the cpu stabilizes at 4.7ghz, when maxing all cores/threads it stabilizes about 4.1ghz. This is after stress testing it for long durations. Temperature didn't matter in the slightest, I could force the fan to max speed and the cpu frequencies didn't budge.

Real world performance on the i9 (in my system anyway): 4.7ghz for low core count or low load across all the cores. 4.1ghz when the system is maxed out.