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xnatex

macrumors member
Original poster
Nov 19, 2012
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I have a MacBook Pro 11,3 (Late 2013 15" -- it was the only one with a GPU in it at the time). It has a NVIDIA GeForce GT 750M in it.
https://support.apple.com/kb/SP690?locale=en_US&viewlocale=en_US

I'm trying to understand if I can run two 4k monitors in a "retina" mode (so that they're visually the same size as 1080p, but crisper), and if so can I do so at 60Hz?

I've spent the past few hours googling and I feel like I know have more questions than answers. I've read that HDMI doesn't support 4k at 60Hz, which is fine, but how about my Thunderbolt 2 ports? I'm also confused by the support article because the resolutions posted are listed under the HDMI section, and don't mention the two Thunderbolt 2 ports. Ideally, I would daisy chain two 27" 4k 60Hz monitors together and also run my laptop open at native resolution. This is what I do today, but the two monitors are 1080p at 60Hz. Is this possible?

If the answer is no, how bad is 30Hz? The primary use for this workstation is programming. I make web apps at work, so my day is spent writing code and also demoing it in a browser. Right now, I'm experiencing some eye fatigue from my two 27" 1080p 60Hz monitors when staring at text for long periods of time (https://www.newegg.com/Product/Product.aspx?Item=N82E16824014300). I think 4k at the same physical size will help me a lot. It's definitely nicer when I get to code on my laptop directly, though I don't have nearly enough screen real estate then (obviously).

Also, some comments that I've read made it sound like running a 4k at a HighDPI 1080p size would be more performant on my GPU than running it at 4k natively (they specifically said that 1080p on a 4k monitor would perform better than 1440p). Considering that, does that change my refresh rate options?

Thanks in advance!
 
A few bits of input.

First, ignore Apple's web page. Don't "Google" for it - search these forums. My input is in here, in the longggggggggg thread about Dell P2415Q/P2715Q thread.

Second, yes. Your rMBP can run two 4k displays @4k @60Hz plus the built-in display at full resolution @60Hz - it's been able to do that since 10.10.3. I owned one of them, there were 6 more in the company I own; I sold mine to a dear friend, the company's units went to a subcontractor that relies on Nvidia GPUs. There are caveats.

Third. The caveats are that you need to have cables that are VESA certified/compliant and have sufficient throughput - don't deprecate this bit, I've harped on this in these forums and you can look up my posts on this bit. There are a few manufacturers that make cables that are compliant/certified and have sufficient throughput - Belkin, Accell, StarTech are the three that I have purchased from, and you'd only want to buy DP 1.2 compliant/certified (not "compatible", a whole different and misleading beast), with those three manufacturers being on the DisplayPort.org product portal.

The DP 1.2 spec gets you maximum throughput options. Why use a straw when you can use a 1" garden hose, a simplistic metaphor? We were able to use the late-2013 rMBP with BenQ/Dell/Eizo displays at 4k with zero issues after Apple finally enabled 4k capabilities. The OS updates of 10.9.3 and 10.10.3 really changed things for the Mac OS relative to 4k displays, the hitch being you'd need to be using certified cables as well.

FYI, ignore TB2. TB2 was/is DP 1.1a compliant - most SST displays require DP 1.2. Also an issue I've addressed in these forums... The ports on your rMBP are both TB2 and DP 1.2 compliant - they're completely different animals, with FW updates enhancing the DP capabilities of your rMBP...
 
This is incredibly helpful. Thanks so much!

I've been searching around the forums for your posts and came across this comment:
https://forums.macrumors.com/thread...nidp-input-doesnt-work.2008528/#post-23764674
It confused me because it seems to contradict the last paragraph on this post.

So, if I got two Dell P2715Q's, would I be able to run them at 4k @60Hz? Based on your comments in my thread I should be able to get two Dell P2571Q's, and these two cables (DP 1.2 compliant :)) and be good to go with daisy chaining (both Accell brand as recommended by yourself and displayport.org). Is that correct?
https://www.amazon.com/dp/B0163LN18M
https://www.amazon.com/Accell-DisplayPort-Cable-Locking-Latches/dp/B0098HW0EA

Also, would you still recommend the P2715Q today? They're currently $360 on Amazon, which seems like a good price. I'm looking for good color accuracy, 4k, and 60Hz. I don't know much about monitors to know how to compare them. I do know that everyone is raving about IPS lately, which I see that this is. And I do understand that I want DisplayPort 1.2 for daisy chaining (which this also is).
https://www.amazon.com/Dell-Monitor-P2715Q-27-Inch-LED-Lit/dp/B00PC9HFO8
 
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Regarding my earlier post, I was addressing TB cabling and not DP cabling - they're completely different beasts, with DP being a subset of TB. The main issue at the time was that manufacturers were not updating their TB cables to the newer DP 1.2/1.2a spec and very few TB-capable displays were available, likely the former was related to the latter point in this sentence. And a 6-ft DP cable (what I generally buy) costs around $15-20 (including tax and shipping) while a 6-ft TB cable would cost roughly 5 times as much. Also, at hand in that thread and a few others I've chimed in was/is that Apple had been and still is "cracking down" on compliance for graphics peripherals - this is just for my experience with the P2715Q and my late-2013 rMBP (2.6 i7, 1TB SSD, 16GB RAM) I think it was 10.9.3 that enabled 4k at 60Hz on one display while limited to 30Hz on the second, 10.10.3 enabled both a larger VRAM partition and as a "side-effect" 4k @60Hz on dual 4k displays (highlighted in that Apple web page - FWIW I notified them of my rMBP being capable, and they've ignored me, but on a side note they don't ignore me after laying out for 5 iMPs a few months ago...). It was with Sierra that external display owners started having issues if they were using non-compliant cabling - one being that SIP required rewrite of a lot of haxies and, if the display "required" DP 1.2 as the P2715Q states in their manual (in my post that you linked to) DP 1.1/1.1a cables just didn't cut it any more and non-compliant cables were causing issues as well; with that last bit here, TB cables that hadn't been updated to DP 1.2/1.2a just didn't work any more - not enough throughput, basically. And, with Apple moving in part to DP over USB, TB 1/2 cables just weren't fiscally worth it to update (I got this info directly from my peripheral vendors). Clear as mud? I'm putting my tech writing sheepskin to good use here...

On your first point, regarding contradiction, what is in this thread and that post are two different matters - DP cables here, TB cables there. Related is that what led me to this subject matter was that Dell was shipping all of their displays at the time with non-compliant cables - this crap goes back at least a decade, affects Win/Linux/Mac computers, crosses manufacturers beyond Dell, and affects millions of customers who wonder why there's freezes/crashes/hardware failures - look up my earlier posts with "power over Pin 20" but it's just easier to get the cables and move on. :confused:

Regarding the P2715Q, it's a very nice display. But, I've got to rain on your parade first - Apple doesn't support display daisychaining of DP displays and that is their official position. The P2715Q and its variants will daisychain over DP on Windows, but it's overrated - with the P2715Q the second display uses DP 1.1a in their implementation of MST, and again Windows only supports this - and the second display is limited to 30Hz at all resolutions, which is fine if you're using it for production work in the line of word processing, spreadsheet work, nothing too "motion based". On a Mac, you'll get mirroring only if you get a picture.

I used two separate DP cables and stuck with USB DAS if I needed both storage and display space. Even daisychaining a second display via a TB device caused display issues due to the cable or device only relaying DP 1.1a (by design, sorry...), so if I needed two displays and needed to connect to a TB storage device at one of my offices, I'd use HDMI with my second display - 60Hz on my DP display, 30Hz on my HDMI display. AFAIK, Apple cuts off all daisychaining of multiple displays, even their TB displays. I've tried it with Mojave just to test it out and still no progress yet. IMHO daisychaining displays at this point on older computers is a bit overrated, and only an eGPU can address this...

That written, yes, that Accell cable is one I use in my house (I still have a 2012 Mini Server, having sold my rMBP to a friend) and there's a few dozen in use in my company. I use an Accell USB-C to DP cable with my iMP and 32" LG 4k display, the same cable is in use with the 4 iMPs in my offices - AFAIK, Accell is the only cable manufacturer that makes a compliant cable of this configuration.

On the P2715Q, it's an acceptable display. I much prefer the BenQ BL2711U for a bit more coin. BenQ's AOC division makes the same panel for both displays and the Dell display that replaced the P2715Q. I prefer the BL2711U due to its more-configurable interface and much better feature set, along with BenQ being far more Mac-friendly and a better processing engine. I replaced all of my P2715Q displays in my home office and offices with BL2711U displays in the CAD and presentation workflows, and moved the Dells to the desks of my PAs. I recommend the BenQ over the P2715Q and its replacement due in part to the Dell's having a dumbed-down OSM and inferior graphics performance in addition to QC issues (see below on this last bit).

About the P2715Q, if you choose to buy one, buy direct from Dell. First, Dell updated some of the internal hardware starting in January 2016 with the significant update being adding HDMI 2.0, which won't help with your Mac's HDMI 1.4 interface; Accell also makes a HDMI adapter in either DP or mDP versions but you'd still have to use a second mDP port. Second, from the first point, there's a good chance you'd get NOS with the older hardware (and non-compliant cables!) while you'd get the latest updates when buying direct from Dell (both HDMI and FW - they're on at least the 5th FW version with the updated display, and I personally equate multiple FW updates on displays with quality control problems that need to be patched). Last, buying direct from Dell gets you much better CS - you'd deal directly with Dell and not the kludgey 3rd-party RMA process they have, I RMA'd a dozen P2715Q displays last October and received the replacement panels in 2 days with return shipping labels in the boxes; the newer panels were still the older model build, but had updated FW, new compliant cabling, and much better build quality. Also, Dell has plenty of discounts available - the business discounts don't apply to personal buyers but they discount for plenty of organizations - AARP, CU members, military personnel, etc. and those discounts are often nothing to sneeze at. I'd get the updated Dell display over the P2715Q just for the hardware improvements that are more or less in in the BL2711U, but with the BenQ's better interface control it's still my first pick...

FWIW, the DisplayPort.org product portal was updated a few weeks ago with dozens of 8k-capable cabling and adapters - I'd hazard a wager that a lot of 4k displays are going to be blown out on sales between now and Labor Day/Black Friday sales! Hope that helps, used up all of my MR Forums time in this post...
 
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I have a MacBook Pro 11,3 (Late 2013 15" -- it was the only one with a GPU in it at the time). It has a NVIDIA GeForce GT 750M in it.
https://support.apple.com/kb/SP690?locale=en_US&viewlocale=en_US

I'm trying to understand if I can run two 4k monitors in a "retina" mode (so that they're visually the same size as 1080p, but crisper), and if so can I do so at 60Hz?


Thanks in advance!

Yes you can, I've been running that configuration (P2415Qx2 + built-in screen, 60Hz of course) for about two years now. You will not be disappointed.
 
campyguy, thanks again for all of your help, I really appreciate it! I'm going to be asking work to replace my monitors soon, but I want to make sure I have a proper shopping list instead of winging it. To clarify, are you saying that I can get both to be 60Hz if I connect both monitors directly to the Macbook Pro as opposed to daisy chaining? I'm definitely open to that if that's what has to be done to make it work (daisy chaining would be preferable obviously, as it's cleaner and less to plug/unplug).

woosher, how do you connect your monitors -- both direct or daisy chained? Do you get 60Hz on both monitors for sure?
 
campyguy, thanks again for all of your help, I really appreciate it! I'm going to be asking work to replace my monitors soon, but I want to make sure I have a proper shopping list instead of winging it. To clarify, are you saying that I can get both to be 60Hz if I connect both monitors directly to the Macbook Pro as opposed to daisy chaining? I'm definitely open to that if that's what has to be done to make it work (daisy chaining would be preferable obviously, as it's cleaner and less to plug/unplug).

woosher, how do you connect your monitors -- both direct or daisy chained? Do you get 60Hz on both monitors for sure?


Both direct of course. I use Accel cables
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campyguy, thanks again for all of your help, I really appreciate it! I'm going to be asking work to replace my monitors soon, but I want to make sure I have a proper shopping list instead of winging it. To clarify, are you saying that I can get both to be 60Hz if I connect both monitors directly to the Macbook Pro as opposed to daisy chaining? I'm definitely open to that if that's what has to be done to make it work (daisy chaining would be preferable obviously, as it's cleaner and less to plug/unplug).

woosher, how do you connect your monitors -- both direct or daisy chained? Do you get 60Hz on both monitors for sure?


Sorry, did not notice. Apple does not give you a way to check refresh rate.
But according to OSD menu it is 60 Hz at 3840x2160 on both. Interestly, all three screens are driven by GT750 now, a year ago or so Apple used integrated graphics to drive internal screen

All in all, late 2013 rMBP is a great laptop, I intend to keep it for the forseable future. It does all what I need.
 
To clarify, are you saying that I can get both to be 60Hz if I connect both monitors directly to the Macbook Pro as opposed to daisy chaining? I'm definitely open to that if that's what has to be done to make it work (daisy chaining would be preferable obviously, as it's cleaner and less to plug/unplug).
Writing, not saying! :D That's the tech writer in me, long frickin' day...

To the point I wrote this post a few years ago - it's kind of scary about my ability to recall, dangerous too as my GF gets to remind me that I pretty much forget nothing, around holidays and anniversaries. My point, silliness aside, is I posted two screenshots of my rMBP with the two P2715Q displays, showing the resolutions of the internal and two external displays. I bring up my GF here as it was her "decree" to clean up my sh*t office - I'm clean, but not tidy... - that led to my discovery, which you can read into my language in that post. That was then, nothing has changed except for better responsiveness with external displays.

The images will show and/or back up what I've alluded to. You're not the first member I've helped in this matter, and I've relied on others in other communities to get to the bottom of this...

Addressing your other directed question, give up on daisychaining displays on the Mac platform. You're wasting your time. Adding to what I wrote earlier in this thread but have addressed in other threads - MST was and always has been a stopgap measure by display manufacturers to address shortcomings in laptops with dGPUs, a non-issue with desktops. Furthermore, respectfully, you need to understand this bit isn't a "cabling" issue but, rather, a bandwidth issue - your rMBP has two buses for DP-related tasks and one bus for HDMI-related tasks, with either DP-related bus not being able to produce enough bandwidth for what you're seeking. If you want two external displays, and you're demanding 60Hz as a baseline, with your Mac you're going to need to use both TB2/mDP ports - even with newer Macs, there is no workaround for this.

After a bit of thought, consider buying the displays that display 4k @60Hz. I bought the P2715Q mainly due to its fairly high DPI - I'm older, use special glasses just for reading and computer use (I also race big block Benzes and have glasses just for my racing, so don't go thinking I'm an old fart!). The AOC panels in the P2715Q/BL2711U displays are IMHO a sweet point in clarity and price point. I type/write a lot, purchasing those displays solely for their high DPI - my point here being that I rarely used them at "4k UHD", with one at HD in portrait and the second at HD in landscape. The text and graphics in my workflow with those displays led to less-fatiguing days. At 4k resolution, however, the macOS GUI not being scaled is more of a PITA if need to get work done, and there's a bigger issue that you haven't addressed here that comes with picking a display that employs native resolution that you really need to GTD - "pixel doubling", relative to DP cable throughput.
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Apple does not give you a way to check refresh rate.
Apple does, in the System Information app, in the Graphics/Displays section. Check my screenshots in my linked post.
 
woosher, thanks for the input! It's really helpful, and great confirmation to everything I've been learning.

Writing, not saying! :D
Haha! Thanks again for your help here. I see that the P2715Q has a mDP as well as a DP, is there a performance difference between the two or anything? I doubt it would make a difference, and also I'm coming from mDP, but with as much stuff as I've learned about monitors in the past few days, I thought I would ask (also worth noting, the BL2711U only has DP and not mDP). Is mDP any different than DP (other than physical plug size)?
 
Haha! Thanks again for your help here. I see that the P2715Q has a mDP as well as a DP, is there a performance difference between the two or anything? I doubt it would make a difference, and also I'm coming from mDP, but with as much stuff as I've learned about monitors in the past few days, I thought I would ask (also worth noting, the BL2711U only has DP and not mDP). Is mDP any different than DP (other than physical plug size)?
Technically, no difference. I prefer the DP port connection on the displays mainly due to the locking connection - all of my displays are on arms, and I frequently rotate my displays - even my iMP is also on an arm (Herman Miller Flo Plus) even though it's not intended to be rotated. With my P2715Q workflow at my home office, both of my two displays was connected via mDP>DP; at my main office where I would fire up AutoCAD or MicroStation my PC was connected to two other P2715Q displays via DP>DP cables - no difference in performance. The cables terminated in different port connections, the only difference. Accell's and StarTech's cables perform identically with the Windows-based throughput utilities I've used for cables that terminate in either mDP or DP port connections.

I'll buy a cable with a locking connection over one without a locking connection.
 
I'll buy a cable with a locking connection over one without a locking connection.

That's a really good point. I have my monitors on arms as well, and while I don't rotate them ever, I might as well get the locking ones since it's an option. Thanks again!
 
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So, I asked my employer for two BenQ BL2711U's and they are concerned because some Amazon reviews mention a "dreaded" issue where the monitor starts flickering really bad. Thoughts? Is there possibly a good alternative? I was really liking the "Anti Flicker" that BenQ said the monitor has (LEDs typically have a high-frequency flicker to them that some people (my wife included) can see).

Is there maybe a different recommendation now? Beyond knowing that I'd like the monitor to be 27", 4k, 60Hz, and DP 1.2, I'm not really sure what else to look for. Also, is DP 1.4 acceptable? I assume anything >= 1.2 is good.

They asked about this, which I really don't know how to answer. https://www.amazon.com/BenQ-EL2870U-3840x2160-Brightness-Intelligence/dp/B078HWN5CX
 
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Thoughts?
Swap out the video cables with certified cables from Accell or StarTech, 5.4GHz per channel. Zero issues with the 18 BL2711U displays in my offices or the several P2711Q displays (same panel on both models), I haven't had to RMA or swap out a single BL2711U.

Regarding the newer BenQ, I'm not a fan of TN panels. The P2715Q's replacement (P2718Q) also uses the same panel with some updated internals. Dell and BenQ have good CS if you buy from them directly or via one of their resellers. My 2¢...
 
Thanks for the reply! I knew that I needed higher quality cables to make sure they can support 60Hz, but I had forgotten that the stock cables can actually cause picture issues. (I was just planning to get Accel ones.) I'm sure that cheap cables is their issue. What a shame.
 
Sorry for the necro post. I'm running into a problem here and I wonder if you guys haven't solved it.

I have a 13" late 2013 MBP, which 100% could drive 4k 60hz on Mojave. Since I "upgraded" to Catalina (and now Big Sur), I haven't been able to select that screen resolution and have been limited to 30hz.

Have any of you guys experienced/managed to fix this?
 
I'm running Monterey on a "MacBook Pro (16-inch, 2021)" and can drive two 27" 4k 60Hz monitors. These are Benq BL2711U monitors. https://www.benq.com/en-ap/monitor/designer/bl2711u.html

I was also able to drive these on my previous MacBook Pro, which was a 15" I believe 2018. It had a touchbar and only USB-C ports.

I'm not daisy chaining them. They're not capable, but also everything I've seen is that they have to be really expensive monitors to daisy chain because of the DisplayPort requirements. So I just have 2 separate video cables running from the monitors to my laptop.

Screen Shot 2022-06-16 at 11.22.27 AM.png
 
Gotcha, I take it you're not using the setup in your original post anymore then? I'm trying to figure out how to restore the 4k 60hz external display setting in my late 2013 MBP.

Looks like you probably upgraded your computer not long after making the OP, so you probably never hit this problem with Catalina on a 2013.
 
Sorry, I'm not. I got a new work MPB in like 2018, then switched jobs this year which got me the 2021 M1 MBP.
 
I have a 13" late 2013 MBP, which 100% could drive 4k 60hz on Mojave.
The 13" Late 2013 Retina MacBook Pro's Intel Iris 5100 GPU is limited to a pixel clock of 450 MHz (Intel doc; page 148), which is not sufficient for "4K" at 60 Hz. I have the same machine and have confirmed this. "4K" at 60 Hz isn't possible using a non-tiled SST display. The maximum refresh attainable at "4K" is 51.8 Hz using CVT-RB v2 timings (calculator).
 
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The 13" Late 2013 Retina MacBook Pro's Intel Iris 5100 GPU is limited to a pixel clock of 450 MHz (Intel doc; page 148), which is not sufficient for "4K" at 60 Hz. I have the same machine and have confirmed this. "4K" at 60 Hz isn't possible using a non-tiled SST display. The maximum refresh attainable at "4K" is 51.8 Hz using CVT-RB v2 timings (calculator).
There is obviously a hardware limit, but isn't the max pixel clock a driver imposed limitation? I don't seem alone in achieving a refresh rate that's noticeable higher than 30.

I suppose it's possible that under Mojave it was displaying at 51.8hz, which is closer to 60 than 30, but that wasn't had with switchres, I just had to plug my monitor in and 4k high DPI was available. I was under the impression macOS would do select a frequency like that.

Even 51.8hz would be a major gain. Do you know how I can set that up?
 
There is obviously a hardware limit, but isn't the max pixel clock a driver imposed limitation?
450 MHz is the hardware limit (as documented by Intel) and is also the limit in Big Sur. Back in 2014 when I was running Mavericks, there was also a driver-imposed limit around 360 MHz.

Even 51.8hz would be a major gain. Do you know how I can set that up?
Define a custom 3840×2160 51.8 Hz CVT-RB v2 resolution in SwitchResX. :)
 
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