iMac 2019 i9 - perfect machine, when App nap is turned off !

[Zdigital2015]

The OP/Tester cannot leave out what he does not know. Why would he think his iMac is defective?
[doublepost=1556329835][/doublepost]

So your workload is nothing like the OP's ?

He doesn’t know what version of macOS he has installed on his 2010 Mac Pro? What version of V-Ray he is using? What GPU he is running? Did you read past the first paragraph before making that inane statement?

Manufacturing defects happen as much as we wish they didn’t.

 

[dcpmark]

That is more plausible. You are not alone. I and other people have had various problems with sleep mode and even screensaver mode. I recently had problems with an upload to DropBox slowing down when the screensaver activated, despite all other iMac power saving features being disabled. In system prefs I had "prevent computer from sleeping automatically when the display is off", yet it still happened. The only way to stop it was totally disable screen saver and I turned down the brightness for long unattended uploads.

This is very interesting to me. I keep my 2019 from sleeping but have the display set go to sleep after 15 min. Normally I have no issues, but today after waking up the display with the mouse the keyboard wasn’t functional at all, even after a restart. It worked again as soon as I plugged it in, and then I was able to disconnect the keyboard and have it work wirelessly again. I wonder if this was related to the screensaver issues??

 

[Melleken]

He doesn’t know what version of macOS he has installed on his 2010 Mac Pro? What version of V-Ray he is using? What GPU he is running? Did you read past the first paragraph before making that inane statement?

Manufacturing defects happen as much as we wish they didn’t.

Sorry, forgot to answer you're questions:

2010 Mac Pro is on Sierra, never had issues with screen server mode or sleep mode, may be kind of logic, because the external screen. Sometimes we even disconnected the screen and the mac pro just keept on working.

We are using V-Ray 3.6.

This is the configuration of our 5,1

* Mac Pro 5.1
* 12-core 3.46Ghz - 3.46GHz X5690 Westmere CPU
* 48 GB - 6x8Gb 1333Mhz ECC ram
* 256 snelle PCIe/flashSSD (voor systeem en programma’s)
* GPU 1 > GT120
* GPU 2 > GTX 780
* extra HD1 > 640GB (backup boot)
*extra HD2 > 2TB (data)
* USB-3.0 (4-poorts via PCIe)
* inclusief wifi & bluethooth module
* superdrive

------------------------------------------

[doublepost=1556374378][/doublepost]Next update of our performance testing:

two screenshots:

1. monitoring this night > screen always on, no screensaver, never go to sleep... > you can see a 'perfect' render performance. iMac finished the testcase render in 1hour 23 minutes, compared to 2hours and 39minutes on the 5,1 - so very nice performance gain. (the green square)

2. monitoring this day > Els is rendering, but also working on photo editing. Then you see whole different story: the iMac is continuously struggling to maintain maximum clock speed. Not thermal throttling i guess, but just the fact other programs are asking continuously also attention and CPU speed. Hard to say what the effect is, but on average the clock speed slows down to the area of 2,6Ghz... So maybe this is perfectly normal, because we never actually did the same monitoring and testing on the mac pro, but i wished i just saw the same performance like when rendering is the only thing the mac is doing; (that is what you see from 12:47hr until 13hr - then Els very quickly eat something...) (the orange square)

That is what we will do the next couple of hours, a comparison of rendering & working on the Mac Pro and looking at the performance of the CPU of the 5,1, because she quite often let the mac render during the night, but most of the time the night is 'long' enough to finish easily, so actually performance during the day, working & rendering at the same time is the most important case.

Really do not know what to do at this point,
send the iMac back?
and go on with the 5,1, but Els was lately very unhappy with the 'single' core performance of this machine, the rendering was great.

First world problems... terrible.

 

[Melleken]

One more update - it is getting strange;

We discovered another strange behavior. Every time you change program, and Sketchup+Vray goes to the background, the CPU stop working full force @3,8Ghz with rendering and drops back to 1,6Ghz. Its like, when to the background the CPU only maximum 'gives' 33% performance, with the crazy effect that when an image is rendering, and you use photoshop or something else in that period, the rendering goes very slow al of a sudden. Bringing back Vray to the front, and immediately the CPU kicks back to 3,8Ghz; (or 4,8Ghz for short bursts)

Did the same on the mac pro with sierra, and their that effect does not exist.
See following experiment, 4 times same render:

1. Sketchup+Vray as active program
Mac Pro 5,1 = 1m 39,9sec
iMac 2019 = 48,3 sec

=> again you see the i9 8core with his turbo boost totally destroying the good old 5,1 in this kind of short test.

1. Sketchup+Vray rendering in the background (not the 'active' program - not even using the program, for example safari)
Mac Pro 5,1 = 1m 40,2sec => exactly the same - what you would expect
iMac 2019 = 2m 16,8sec => terrible performance drop, a lot slower than Mac Pro, but espacially crazy slower then the same computer !!

=> forget the nightly problem - If we do not find a solution for this situation, the iMac is not even an option because of the daily workflow - a lot of 'background' rendering !

Does anybody recognize this problem? Or knows a solution?
(need to know this before tomorrow ! if no solution, iMac goes back, if a simpel solution, iMac can stay)

If someone should ask:

It is very easy to see and very reproducible, the moment you switch to another program, nothing happens yet, the moment you do 'something' (can be anything) in that other program the clock speed falls back to around 1,6Ghz, then i could jump back up, if you keep on doing demanding stuff in that program, but the CPU is then 'reserved' for that program, and Vray in the background, does get anything more, NOT EVEN WHEN the CPU has nothing to do at all !!!

So you get the strange effect of an computer that is doing nothing els but rendering, and still only uses 33% of its power at that situation... a situation that in real life, in our workflow, is like a very common situation !!!!!!)

 

[michaelrdk]

It is very easy to see and very reproducible, the moment you switch to another program, nothing happens yet, the moment you do 'something' (can be anything) in that other program the clock speed falls back to around 1,6Ghz

Did you see my post #22 about App Nap? This sounds a lot like that feature reducing CPU when an app is in the background. Have you checked the Energy tab in Activity Monitor?

 

[Melleken]

@michaelrdk > we have tested it, with and without App Nap chechbox on... same result.
Do you have to reboot to have change in effect with App Nap, because it was on at first...
[doublepost=1556391118][/doublepost]read the article again, and i agree totally - it sounds very much like App Nap 'feature'...

i will do first some further investigation with app napp, starting with a reboot, with the function off...
[doublepost=1556391234][/doublepost]aha, quick question, i was wrongly thinking 'app nap' was the same as 'power nap', but that is probably my mistake?

damn, new computer, no experience yet with high sierra or mojave, i feel like an noob again.

and damn, i did not saw or used that word in ages... were is the time that you had 'noobs' on the internet...

[doublepost=1556392104][/doublepost]...
did some reading about app nap, seriously thinking to shut i down completely (trough terminal command)
will test it now (shut i down) but it seems that killing app nap wil be the solution for that last problem...)

@michaelrdk - thank you for you're help !!!
[doublepost=1556393011][/doublepost]and, after the reboot & testing it > it is app nap. (found the indicator per app in activity monitor) and the moment the performance drops in intel power gadget, the indicator turns to 'yes'.

 

[michaelrdk]

You’re welcome, I’m glad to help. I would suggest turning App Nap off completely for your usage.

 

[Melleken]

@michaelrdk

FINAL CONLUSION > the problem was app nap for everthing !

Now that app nap is 'killed" systemwide, their are no issues any more with screensaver, sleep modus or anything else.
Very logical when you understand app nap, but this is a complete hidden 'feature', so i am pretty sure al lot of people are working on their macs, having done some benchmarks, and test while focusing on the program, and everything looks very good, but then start really doing work and by default multitasking, even if that is checken facebook on safari, and then their supercomputer is slow down dramatically as a 'feature' by app nap.

Perfect example of apple thinking standard consumer (what i hate, but can understand very good: money!) and add feature or makes decisions that are really really bad for pro users.

So for the most pro users > turn that app nap feature off !!!

 

[amoergosum]

FINAL CONLUSION > the problem was app nap for everthing !

So how long did the render take after you turned app nap off ?

 

[Melleken]

So how long did the render take after you turned app nap off ?

which render? The long nightly render?

 

[amoergosum]

which render? The long nightly render?

This render:

But this night i planned a final stress test - an render that took 2hours and 39 minutes on the Mac Pro 5,1, was setup and started on the iMac 2019 i9 this night, hoping and expecting to see may be the iMac finishing in less the 1,5hours.