Questions RE 4K external display driven off macbook pro

[keiran_harris]

im a relative n00b here so please be gentle I am quite techy though, so hopefully not embarrassing myself too much!

I have a 2014 13" macbook pro, which i adore. Esp the retina display. BUT the screen real-estate is starting to hinder me for my work (im a network engineer, having many apps open at once is key). So, consequently, I have been looking into external display options. The Samsung U28E590D is a frontrunner (3840x2160 "4K ultra HD"). However i have some questions before i purchase that no amount of reading seems to allow me to de-tangle, and in fact, i seem to be confusing myself the deeper i go!

so here are my questions, any and all help is appreciated from the guru's on this forum:

QUESTIONS:
1/ my MBP graphics card supports (from the apple marketing specs) "up to 2560 by 1600 pixels on up to two external displays".... the new samsung has more pixels that this [3840x2160], and not in a "nice", ie. 2x multiple of either, so what happens here? Scaling I guess. Is this handled by the monitor? or the MBP OS? will i notice blurry text etc as a result? Clean, crisp lines / text are important to me. Will the scaling introduce noticeable lag?

2/ How to feed this monitor: HDMI vs displayport? The monitor supports both, but from what i can gather HDMI output from my MBP only allows "Support for 1080p resolution at up to 60Hz", which is well short of what my GPU can drive [2560x1600]. So i guess this scrubs HDMI? I do see that if i bump down to 30Hz it supports for 3840x2160 (the exact samsung res!) but do i want to go there? what does halving the refresh rate do to usability on modern monitors? im mostly about application productivity, not gaming etc...

3/ Assuming we scrub HDMI, it leaves displayport. It seems my MBP has 2x thunderbolt-v2, which supports displayport-v1.2 (~18Gbps, the standard designed to support 4K monitors @60fps)... so this would appear to be a good thing, BUT looking here (https://support.apple.com/en-au/HT204149) it seems if i get the single-port-to-DVI-adapter it supports only 1920x1200. The dual-link version allows me to go over this (upto what is unclear)... should i be purchasing this dual-link adapter? I guess so, to be able to push the maximum out of my GPU, but this then circles back to my question-1, i.e. will the resolution mismatch make things look crap.

4/ somewhat bizarrely, the Samsung U28E590D doesn't have a DVI input. This means i guess i have to do something like this:
MONITOR[displayport]<-> DISPLAYPORT-TO-DVI-ADAPTER/CABLE <-> DUAL-LINK-APPLE-ADAPTER <-> MBP
I assume there is no pitfalls associated with this? please don't tell me there is another resolution calculation to make because of this!

5/parallels is *sometimes* noticeably laggy (ie 1 second click / refresh delay!) when i run an external monitor. Most of my work apps are run out this VM unfortunately. Ive yet to get to the bottom of this. OSX appears to be fine, just the VM suffers. Is this problem likely to get worse on a higher res display?


I guess all this boils down to is: will i be happy purchasing this new display, or will the fact that its such a high res actually be a step backward with all the above pitfalls (or alternatively, am i looking far to deep into this!!!).

thanks in advance guys
K.

 

[Fl0r!an]

I think your MacBook should support 4k 60Hz with a MST display. SST displays or HDMI connection should run at 30 Hz.
There's a Apple support document on 4K and UHD stuff, better have a look for this.

Using a lower resolution than native is no good idea as it will result in blurry graphics. That's why your display doesn't offer a DVI connector, it just doesn't make any sense. DisplayPort is the way to go.

 

[zhenya]

Officially, I believe that your particular laptop is limited to 4k@30hz via the HDMI port. https://support.apple.com/en-us/HT202856

Unofficially, I believe you may be able to hack it a bit to get 4k@52hz via displayport. https://forums.macrumors.com/threads/4k-display-and-retina-macbook-pro-13.1741440/
Specifically look at this post. https://forums.macrumors.com/thread...a-macbook-pro-13.1741440/page-8#post-21379266

I don't have this model of machine, but it's basically the same hack I use to drive a 4k monitor at 50z on my Surface Pro 3.

You might prefer to get one of the ultra-widescreen curved monitors that are still very high resolution, but slightly below 4k though as they should work natively at 60hz with no hack. If you do want 4k, can you get a Dell monitor where you live? They make very nice 4k monitors at a reasonable price.

 

[inkyoto]

zhenya is on target with the resolution stuff. See the Apple Support page: SST/MST 4k@60Hz is only supported on MBP 13" for MBP 13" Early 2015 machines or later.

It seems like people with MBP 13" Late 2013 have been able to get 4k@52hz working with the Samsung and Dell displays. 30hz is pretty bad, I think, and I don't play many games. 52hz is definitely close enough to 60hz that it would work fine.

By the way, I'd recommend that you go for a Dell 4K monitor, not the Samsung one. When I was deliberating which one to get, a few people on this forum have talked about how the Dell one would be better, since it uses higher-quality IPS panels, unlike the TN panels used by the Samsung. The closest to the Samsung would be the 27" Dell P2715Q.

 

[pastrychef]

1. I think that your MacBook supports 4K@60Hz. Double check with Apple support docs to make sure.

2. The current HDMI standard is limited to 30Hz. To get 60Hz, you should use DisplayPort 1.2.

3. On a 4K monitor, just use DisplayPort or Mini DisplayPort. Don't bother with DVI-D because it won't work in 4K resolution.

4. See above.

5. Sorry, I don't have any experience with Parallels. However, some people have reported experiencing lag even in OS X when using 4K monitors in scaled resolutions. This is because the scaling is done by the Mac's GPU. If the GPU is not powerful enough, users may experience some lag.

 

[Fl0r!an]

zhenya is on target with the resolution stuff. See the Apple Support page: SST/MST 4k@60Hz is only supported on MBP 13" for MBP 13" Early 2015 machines or later.

Did you read the article?
MST 4K@60Hz => 13" Early 2013 or above

=> Answer: He did, I can't read.

 

[zhenya]

Did you read the article?
MST 4K@60Hz => 13" Early 2013 or above

So far as I can see in that article it says nothing of the sort. Which would make sense, because the Haswell chips in those laptops max out at 52hz for 4k as per the other links above.

 

[keiran_harris]

thanks for all your input above ^ guys. Ive definitely learnt a thing or two.

In parallel to absorbing your replies, i also came across this: http://thewirecutter.com/reviews/best-4k-monitor-doesnt-exist/ which is a great article (and the ones it links to) that seems to sum up my concerns well. Namely: the tech in 4k monitors is bleeding edge; the cost vs. tech[ie no cheap IPS panels] sweet-spot has yet to be established; OS / app support for high-rez displays is still shaky; and the h/w demands a beefy GPU.

addressing some comments above
- [Fl0r!an] and [pastrychef] you guys said "I think your MacBook should support 4k 60Hz with a MST display" >> apparently not. [inkyoto] and [zhenya] seem to confirm. Basically, I have a late 2013 13" MBP, if i had the late 2013 15" you guys would be right, but even then, only in MST mode.
- [inkyoto] RE Dell v Samsung. I can get Dell, but i have $800 voucher at a local store and they stock the Samsung! (dell is online only right?)
- [pastrychef] the samsung does have HDMIv2 port which supports 4K @ 60Hz. But yeah, my MBP will only threw the signal out at 30Hz (HDMIv1.4 port) so not much point.
- [Fl0r!an] thanks for confirming that running an external monitor at lower than its native h/w resolution will look crap.
- [zhenya] thanks for the 52Hz hack! why the heck doesnt apple offer this out of the box im not sure... if the h/w supports its why choke it? Im slightly worried about how this will affect my parallels VM environment. I could probably go to a store and try it out.
- [pastrychef] and [Fl0r!an] thanks for confirming DVI ports dont support 4k, hence their absence on the samsung makes sense.

other things I've learnt
- usability at 30Hz would appear to be a definite no-no (noticeable flicker). So that scrubs the HDMI 1.4 interface.
- MST v SST. Sounds like MST a poor mans SST (i read of some weird issues with MST). So if possible design your setup with both ends on SST (ie new hardware).

questions i still have
A) im still unclear of the mechanics to connect my MBP to the Samsung. Seems HDMI is scrubbed (as its only 30Hz max). Leaving DisplayPort. But dont i need the dual-link DVI adapter in order to run resolutions greater than 1920x1200 (upto i guess, my GPU limit of 2560x1600). BUT in the same breath, ive been told above NOT to run it through DVI. How else then do i connect it? Is there some magical cable that goes from thunderbolt to displayport allowing highest res?
B) If i bail on the 4K path (as [zhenya] suggests), would i be advised to seek out a monitor with *exactly* the same hardware pixels as my GPU supports... ie 2560x1600 which is the "WQXGA/wide-quad" standard? What happens then as i upgrade laptops? clearly we have established that if your GPU < monitor hardware pixels its BAD, but if the GPU > monitor pixels will the GPU just scale back what it offers to the monitor without the yukky blurry/fuzzy/lag scaling issues? I notice my GPU is very close to the 2560x1440 (WQHD) resolution which there seems to be a lot of monitors around for.... but the rez is a close, but not exact match, is this ill advised?

Im astounded at how complex this topic is, lord knows how anyone without an IT background would navigate this!

thanks so much for your help guys... a real expert community here!
K

 

[pastrychef]

The article you linked to, "Best 4K monitor doesn't exist", is a bit dated and I don't think the information on it is relevant anymore. My IPS 4K monitor cost me $550 and I've seen it sell for even less after I purchased mine.

Ah... In your original post, you said you had a 2014 MacBook Pro, so I thought your model could support 4K@60Hz.

Scaled resolutions DO NOT look blurry at all. At least not to my eyes. (My vision may not be what it used to be but I have never needed any eyeglasses.) I run my 27" 4K monitor at 3200x1800 resolution and everything is extremely sharp and clear. By comparison, my 4K monitor at 3200x1800 looks sharper than my old Dell Ultrasharp 30" monitor running at its native 2560x1600 ever did.

I don't know which monitor Fl0r!an used but my experience is the total opposite of his. Like I said, I use my 4K for many hours everyday and have done so for the last 4+ months. Keep in mind that MacBooks and MacBook Pros with Retina Displays default to a scaled resolution. Do they look blurry to you?

In regards to the Samsung 28" 4K monitor, I looked at it fairly extensively when I was shopping for a 4K monitor and I found the TN panel that Samsung uses is far inferior to the IPS panel used in the Dell 27". If you have a chance, try comparing the two yourself. I'm sure you will agree with my assessment.

MST was an earlier standard that has been largely replaced by the much better SST standard. Given a choice, go with SST.

How you scale the resolution on your monitor is completely up to you. It is a preference that you set in System Preferences.

Based on how you choose to scale the resolution, you could possibly place a heavier burden on your GPU. A weak GPU can potentially cause you to see lag.

 

[Fl0r!an]

So far as I can see in that article it says nothing of the sort. Which would make sense, because the Haswell chips in those laptops max out at 52hz for 4k as per the other links above.

Hehe, you're right sorry. Didn't notice they swapped 13" and 15" in the 2nd paragraph. So, I'm obviously the one who can't read properly.

@ pastrychef: I don't have a 4K display myself but that's my experience from playing around with differente "retina-level" screens. Scaling doesn't look as bad as on displays with low resolution, but driving it in native resolution with HiDPI mode (liek the scaling Windows does) looks way better to me. Of course this depends on the viewing distance, and maybe the interpolation functionality in the screens might also differ.
If I remember it correctly (I don't have a rMBP myself), all Retina Macs default to @2 scaling like the iPhones do. This will drive the screen at native resoluation and the system will increase the size of everything by factor x2. So there's no interpolation involved resulting in the best possible experience.

 

[zhenya]

@Fl0r!an I know - that paragraph is hard to read!

@pastrychef I agree with the assessment of the Dell vs. Samsung panels. We have one of each at our office and the Dell is unquestionably better.

@keiran_harris MST is multi-stream transport. SST is Single-Stream Transport. MST is intended to allow daisy-chaining of displays - one connector to the computer to the first monitor, second monitor connected to the first. Some early 4k displays used it as a hack to drive a single display because at the early stages, lack of bandwidth was a big problem in driving a 4k display and MST was a way to get around that in some cases (with a MST screen and the right drivers, the screen was treated as two 1920x2160 images, which many more graphics cards could drive, as opposed to a single 3840x2160 image which they couldn't). Heck, today bandwidth is still an issue, but for the most part you probably want to buy a SST display. If it can daisy-chain, it is using SST.

 

[pastrychef]

I'm saying that my 4K monitor scaled to 3200x1800 resolution looks sharper and clearer than my old Dell Ultrasharp 30" running at its native 2560x1600. I sit approximately 2 feet away from the screen.

Yes, the Retina Display MacBooks default to 2x scaling. But it's still scaling... Plus, who's to say the OP won't decide to use a 4K display at 2x scaling himself? All you said was, "Using a lower resolution than native is no good idea as it will result in blurry graphics." Implying that any scaled resolution would result in blurriness.

Here, you see pictures of my previous posting on this thread. One at the native resolution of 1920x1200 on a 24" Dell Ultrasharp and another on a Dell 4K scaled to 3200x1800. Judge for yourselves whether you can see any blurriness. keiran_harris, you can also try using different resolutions on your MacBook to see what scaling will look like.

 

[Fl0r!an]

Yes, the Retina Display MacBooks default to 2x scaling. But it's still scaling... Plus, who's to say the OP won't decide to use a 4K display at 2x scaling himself? All you said was, "Using a lower resolution than native is no good idea as it will result in blurry graphics." Implying that any scaled resolution would result in blurriness.

Yeah, I wasn't precise enough on that. It's actually not "still scaling", but two different types of scaling:

• Using OS X HiDPI 2x mode will run the screen at it's full native resolution. Apps with retina artwork (@2) will dispaly their graphics in full resolution, older apps will use pixel doubling. So, on a 4K display in HiDPI mode OS X will use the native 3840x2160 resolution but you'll only have the size of a 1920x1080 display. The resolution is used just to make the graphics more crisp, not to increase the usable area.
  
• Non-HiDPI resolutions will instead send a lower resolution signal to the screen. Your display will then have to interpolate this signal to make it match the physical pixels of the screen. This is by concept inferior to the first solution, results may vary with the specific resolution and the screen. For example, running a 4K screen at 1920x1080 will make it look exactly like a FullHD display, because no interpolation is needed, just pixel doubling. Running it at the (theoretical) resolution of 1920x1100 will make it look worse, because the screen would have to interpolate in vertical direction to fit 1100 logical pixels on 2160 physical pixels. It would certainly look better on a 4K screen, but not good.

Windows offers another approach: They allow you to drive the screen at it's native resolution and let the computer do the scaling, even with non-2x factors. In real world applications this is almost as good as "real Retina HiDPI", because Fonts (this is were the resolution is most obvious to me) are vector based and can be scaled freely without any interpolation.
The difference between this "Windows scaling" and just lowering the resolution is enormous on classic low-DPI screens and still visible on "Retina-level" displays.

 

[pastrychef]

Yes, I understand how the concept of HiDPI works. You are still basing everything you are saying on the theoretical concept when you say "Running it at the (theoretical) resolution of 1920x1100 will make it look worse, because the screen would have to interpolate in vertical direction to fit 1100 logical pixels on 2160 physical pixels. It would certainly look better on a 4K screen, but not good." In practice, I have found the HiDPI resolutions available in OS X to be exceptionally sharp and clear. This is probably due to the the dot pitch because the PPI is so high that individual pixels can not be seen by the naked eye. Even on my old 30" monitor at 2560x1600, when viewed closely (a few inches away from the screen), I was able to see the individual pixels on the panel. This is not possible on my 4K monitor without the assistance of a magnifying glass.

I think you need to spend more time in front of a 4K monitor before you tell people that scaled resolutions won't look good. It looks exceptional to me.

Btw, using one of the scaled HiDPI resolutions will put a bit of load on the GPU. That's why some users who have underpowered GPUs report a bit of lag.

 

[Fl0r!an]

In practice...

... it all depends on the combination of viewing distance, display size and resolution. On Apple displays with their 220-230ppi I barely can tell a difference between between non-x2 scaling and "real" Retina, on usual 4K displays with their 28-30" (resulting in <160ppi) it's more obvious.

The main reason I don't "spend more time in front of a 4K monitor" is in fact that I don't like the scaling options in OSX. On a 27" screen (reasonable size for me) I'd like to have a desktop size that equals around 2560x1440 (quite common), just with increased sharpness. Sadly OS X only offers x2 mode (1920x1080 HiDPI) which would be a waste of screen real estate. Setting the resolution to the desired 2560x1440 would in best case result in the same image quality of a QHD 27" displays, so I'd be better of buying a cheaper QHD display.
Using Windows with native 4K resolution and non-2x scaling would get me quite exactly what I want, but in OSX this seems to be only possible with some obscure hacks I never managed to enable on my Macs (maybe because of Radeon graphics?).
But instead of implementing proper scaling Apple prefers to sell 5K screens so they can keep their x2 mode...

 

[pastrychef]

You can enable access to HiDPI resolutions with a terminal command. Instructions are here.

 

[Fl0r!an]

Yeah I know, but I never managed to get a non-2x HiDPI resolution to appear. Maximum was 960x600 (HiDPI) on a FHD display and 1920x1080 (HiDPI) on 4K, but nothing from the thread I linked.

 

[keiran_harris]

Thanks so much for your replies guys. I learnt a lot. Based on discussions here and other readings, i took a rather novel approach to solving my core issue which was lack of real-estate on my 13": i purchased a new 15"!! (Coincided with a time that my wife needed a retina screen so she got the hand-me-down). I also changed the display resolution to "more space" which now with the bigger screen yields exactly what i need.

I ended up getting the top of the line 15" for two reasons: first it had a 500GB SSD (the 250 i had in my 13" was always a bad move for me running VMs); second, and most importantly for this thread, it has a powerful video card [AMD Radeon R9 M370X] capable of driving a 2x 4k external monitors, or even a single 5k (!!) monitor.....

[side note: the above is all via thunderbolt/displayport, it surprises me the HDMI out is still only max 1080p @60HZ. They mustn't have upgraded to HDMI V2.0 hardware/chipsets for reasons that escape me as its been out since 2013]

Anyhow, lesson learnt here with respect to future proofing the video card if I'm even vaguely contemplating running external monitors.

I will still buy an external display but im going to wait 6 months or so when IPS panels on 4k is more ubiquitous and prices come down.

Thanks again all.
Very happy with my setup now.
K

 

[bootz]

My two opinions on the topic after using my rMBP over the last 3 years with a variety of external monitors:

1. HiDPI looks fabulous, as long as the mode you are using is equal to half the actual native resolution. If the native resolution is 1440p, you have to run at 720p. HiDPI 1280x720 looks awesome on my U2515H (unfortunately the real estate is way too small for a 25" monitor).

2. Any other HiDPI resolution may look good, however it won't look as good compared to a monitor that runs at that resolution natively.