Mac mini 2018 bad UI-performance with LG 5K-Display

johnscully

macrumors member
Original poster
Sep 11, 2010
72
20
Hi,

got a new Mac mini (Core i3, 8 GB RAM, 512 GB) a few days ago and I thought using it with the LG UltraFine 5K Display would be the ideal combination. The Display is great, but the Graphics-performance not so much. I'm experiencing frame dropouts all over the place (for example with animations like the one in Mission Control, where you see all open windows at ones; or opening apps). I also think scrolling in Safari and a few other Graphics-related tasks are a bit more choppy in comparison to an iMac from 2017. By the way: There are no Performance-intensive tasks in the background or anything like that.

Is it possible that the Mac mini is too underpowered for the needs of the LG-Display? I understand that my configuration is entry-level (Core i3, 8 GB RAM) and the Intel-Graphic isn't exactly a performance-king (politely speaking), but the machine should handle the basic UI-tasks without any problems, or not? Or would for example a Core i5 help even with UI-Performance? I don't need high performance (don't do Video-Editing etc.) and thought the Core i3 would be enough for my needs.
 

T-Bob

macrumors 6502a
Oct 23, 2013
616
310
Have been a few others that have tried the 5k, and one poster from yesterday that uses it as their configuration so will hopefully chime in.

All the Mac minis have the same gpu, and the base cpu configuration is far from weak. Let's see what some others say. I don't have the MM but do use 5k and mission control is quite smooth (but slower than it can be) on MBP 13" when using it as an external.
 

ncrypt

macrumors 6502
May 16, 2012
341
233
UK
Sorry to hear that OP. There is some difference in the GPU between the i3 and i5/i7 though.

Looking at gpu benchmarks, with the i5/i7 on the left, and i3 on the right, there's a 20% performance difference:
https://gpu.userbenchmark.com/Compa...s-630-Desktop-Coffee-Lake-i3/m356797vsm359294

Also, when you compare the mini's 3 processor options, the i7's graphics actually runs 100MHz faster than the i3/i5:
https://ark.intel.com/compare/126688,129939,134905

I would maybe consider another processor option other than the i3 if you want to use it with a 4k display.
 

Spectrum

macrumors 68000
Mar 23, 2005
1,623
939
Never quite sure
I think what you see may be what to expect unfortunately.

I have run a 2011 i7 quad mini with a 2560x1440 display for 7 years, and the UI animations are are not perfectly smooth.

The new UHD630 may be ~3x faster than an HD3000 (in the 2011 mini), but the number of pixels on a 5K display is 4x what I have...and if you do any scaled resolution it may get even more demanding.
 

T-Bob

macrumors 6502a
Oct 23, 2013
616
310
Yes the default scale is 200% (looks like 1440) and it should work quite well. On the 550 that I use it is hitting 60 for a lot of the time that I can tell, or very close to it. Here is comparison between the MM cpus:

https://ark.intel.com/compare/126686,129939,126688

The i7 has a small boost, and i3 has lower memory bandwidth. It might be the lower memory bandwidth that is hurting its graphics performance. Perhaps you need to return and get an i5 or i7?

Edit: Missed similar post above with CPU comparison.
 

HappyIntro

macrumors 6502
Apr 30, 2016
260
256
Well, you could spend $300 extra if you return your i3 and get the i7, or you could spend $699 extra to get the Blackmagic eGPU. The former may help, but the latter should provide a much larger boost to video performance. Just thinking out loud.
 

netnothing

macrumors 68040
Mar 13, 2007
3,674
305
NH
Yes.

You can try actual native 5k revolution if you want with:

http://easyresapp.com

It's pretty much unusable of course but lets you see what 5k would look like without scaling.
The default for the 5K iMac is 2560x1440 correct?

I'm looking to maybe get the new Mac mini and the LG 5K, but reports like this have been second guessing myself. I'm coming from an old 2010 Mac Pro with a Dell 27" running 2560x1440. I want to keep that same resolution, but want the 5K display for the crisp text etc.

Maybe there is a big difference between the i3 and the i5/i7 when trying to run that 5K display.
 
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T-Bob

macrumors 6502a
Oct 23, 2013
616
310
The default for the 5K iMac is 2560x1440 correct?

I'm looking to maybe get the new Mac mini and the LG 5K, but reports like this have been second guessing myself. I'm coming from an old 2010 Mac Pro with a Dell 27" running 2560x1440. I want to keep that same resolution, but want the 5K display for the crisp text etc.

Maybe there is a big difference between the i3 and the i5/i7 when trying to run that 5K display.
Yes it is always 1440 default, multiplies evenly. If you try adjusting the scaling further from that, it slows down performance. I am also considering the MM on this monitor, so hope we get more impressions from other users.

Anyone with X code and developer account can also use Quartz debug to measure frame rates if they are so inclined.
 
Last edited:

magbarn

macrumors 68020
Oct 25, 2008
2,307
1,412
Well, you could spend $300 extra if you return your i3 and get the i7, or you could spend $699 extra to get the Blackmagic eGPU. The former may help, but the latter should provide a much larger boost to video performance. Just thinking out loud.
At that point you might as well get a iMac 27 with an easy discount and get the 5k screen for free...
 

johnscully

macrumors member
Original poster
Sep 11, 2010
72
20
Thanks for the input!

Probably I'll go to the Apple Store in my city and test the UI-Performance of a Core i5-mini there. Last time I was in the store at least one mini was hooked up to LG UltraFine 5K. I tested the iMac too, but 1) the fans where too loud in Idle-Mode (at least for my taste; one of the factors for the Core i3-Purchase was the silent-aspect of the machine) and 2) I have a problem with spending full price for a nearly 1,5 year old computer with 7th Generation Intel-Chips.
 

netnothing

macrumors 68040
Mar 13, 2007
3,674
305
NH
Thanks for the input!

Probably I'll go to the Apple Store in my city and test the UI-Performance of a Core i5-mini there. Last time I was in the store at least one mini was hooked up to LG UltraFine 5K. I tested the iMac too, but 1) the fans where too loud in Idle-Mode (at least for my taste; one of the factors for the Core i3-Purchase was the silent-aspect of the machine) and 2) I have a problem with spending full price for a nearly 1,5 year old computer with 7th Generation Intel-Chips.
Please report back with what you find. It will be really disappointing if the new mini can't handle the 5K display. I don't need to do anything graphics intensive.....but would like the machine to simply power the 5K display smoothly.
 
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TheBigApple2006

macrumors regular
Feb 20, 2006
236
14
I have the LG 4K display hooked up to the core i7 Mini, with stock 8GB RAM. UI is very fluid and generally works well. Hiccups do occur however, but usually when swaps are high (say 1.5 to 2GB) and the system has run out of RAM. I would suggest to pay careful attention to Activity Monitor’s memory usage reporting, as chances are there is a hogging of RAM between the UHD 630 and physical (regardless of CPU consumption) that is causing the stuttering. I am living with it while waiting for 32GB Ram prices to come down, its not requiring urgency in that regard.
 

Ice Dragon

macrumors 6502a
Jun 16, 2009
986
20
My local Apple store had the i5 mini on display hooked up to the LG 5k (is it?) monitor.
 

ElectronGuru

macrumors 68000
Sep 5, 2013
1,517
369
Oregon, USA
Thanks for the input!

Probably I'll go to the Apple Store in my city and test the UI-Performance of a Core i5-mini there. Last time I was in the store at least one mini was hooked up to LG UltraFine 5K.
Apple seems to be demoing minis with 5k so we would expect them to work well together. But Apple may also know something we don’t. Replies here suggest cpu or ram.

i3/16 may be enough or i5/8 may be or both. We can (collectively) start reporting cpu/ram/etc Apple is using to look for patterns.
 

archer75

macrumors 68030
Jan 26, 2005
2,853
1,407
Oregon
I run an i7 mini with a 34" ultra wide screen at 3440x1440. I know it's not 5k but it does work great, no issues.
 

netnothing

macrumors 68040
Mar 13, 2007
3,674
305
NH
I run an i7 mini with a 34" ultra wide screen at 3440x1440. I know it's not 5k but it does work great, no issues.
What monitor? And does it look ok with Mojave? I didn't like the new font antialiasing on non-retina displays.
 

magbarn

macrumors 68020
Oct 25, 2008
2,307
1,412
Thanks for the input!

Probably I'll go to the Apple Store in my city and test the UI-Performance of a Core i5-mini there. Last time I was in the store at least one mini was hooked up to LG UltraFine 5K. I tested the iMac too, but 1) the fans where too loud in Idle-Mode (at least for my taste; one of the factors for the Core i3-Purchase was the silent-aspect of the machine) and 2) I have a problem with spending full price for a nearly 1,5 year old computer with 7th Generation Intel-Chips.
Then wait if you can. That's what I'm doing. An 8 core/16 thread imac is going to be awesome. I think Apple is waiting for 9th gen chips to be in better supply before updating the imacs. Try buying an i7-9700k or i9-9900k, they're rarer than hen's teeth right now.

With DDR4 Ram being finally reasonable in price and with a top of the line Samsung 970 Evo 500gb going for $99, I'm not ready to throw my money away on the mini.
 

archer75

macrumors 68030
Jan 26, 2005
2,853
1,407
Oregon
What monitor? And does it look ok with Mojave? I didn't like the new font antialiasing on non-retina displays.
It's a Dell. I don't recall the exact model number off hand. They are individually color calibrated at the factory. It looks great to me.

On a side note I got the very first Dell LCD they ever released. Must be 18 years old or so? I still use it as a side monitor and it still works great.
 

ikaka

macrumors regular
Mar 5, 2009
136
24
I have 2x 4k monitors hooked up to the i7 mini with 8gb and I also see it stuttering significantly, but I believe the issue is in memory, since it needs about 3.5-4GB to run 2 4k displays, therefore the system has only 4gb left for everything else and for MacOS is super low and then the video memory starts swapping and boom. I have 32GB coming this week, hope it fixes it.
 
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