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inkyoto

macrumors regular
Original poster
Oct 30, 2013
176
15
I posted before about opinions comparing the Dell 24" and 27" displays. In an effort to figure out which display would be better, I purchased both the Dell 24" (P2415Q) and 27" (P2715Q) displays to compare them and see which one would be better as an external monitor for my MacBook Pro Retina 15" (planning on using the one I don't choose for hacks and projects).

Questions
  1. Will either the 24" or 27", with lower pixel density (PPI) than the MacBook Pro Retina 15", have a noticeably lower PPI (i.e. appear less 'retina')?
  2. Does scaling to a larger resolution than "Best for display" result in a lot of blurring?
  3. Will the 27", which fits the same amount of pixels on a larger area, have a noticeably lower PPI (i.e. appear less "retina")?
  4. Will apps look way too big on the 27" because they'll get blown up?
  5. Is the additional 'space' (area-wise) on the 27" make it worth the trade-off of lower PPI?
  6. Any performance problems with running each display?
Review materials
  • MacBook Pro Retina 15" Late 2013
  • Intel Core i7 2.6 GHz
  • NVIDIA GeForce GT 750M 2048 MB
  • Mini DisplayPort to DisplayPort connection
  • Reference: Video – Costa Rica in 4K; Text – Instapaper; Web: The Verge, MacRumors
Display configurations
  • Main: Best for display (2x Retina exact; 1920 x 1080)
  • Scaled: 2560 x 1440
  • Scaled: 2304 x 1296
Review 1 — Dell 24" Display

TByHqLM.jpg


Holy crap, this thing is beautiful. Any worries about the lower PPI leading to a lower quality Retina experience – nope. This thing is buttery smooth. Text is incredibly crisp and videos, especially 4K videos, are gorgeous on this screen – likely a testament to the IPS panel in this display.

However, UI elements are a bit large but they're not out of control. The display is a good size and offers a decent amount of extra space compared to the MacBook Pro's screen.

On the other hand, scaled resolutions do produce a noticeable amount of blurriness – text isn't quite as crisp and things just seem a bit muddy. [EDIT: pastrychef suggests turning off LCD font smoothing when using scaled resolutions by going to System Preferences > General, which helps a good bit in making the text less fuzzy and less bold.]

Question 1 – Noticeably lower PPI? – Nope. Looks just as good as my MBP.

Question 2 – Scaling resolution performance – Noticeable blurring. A little annoying, but the annoyance dissipates with use.

Questions 3–5 deal with the 27" so they're skipped.

Question 6 – Performance problems? – Some lag when driving the scaled resolutions at 1440p or 1300p.​

Review 2 — Dell 27" Display

EFkUZqp.jpg


This thing is huge. Like blocking-the-sunlight-from-my-window huge. It's only 3" more than the 24" but it's noticeably larger. Watching the Costa Rica 4K video was pretty awesome on the 24", but it was unreal on the 27" – much more immersive.

However, UI elements are slightly even larger than the 24" as expected, though I've been using this one for hours and haven't noticed any negative effects from UI being that large. I generally prefer large UI, however, so this might just be me. I find that I can fit many things on the screen, however, which is pretty nice.

Scaling does introduce blurriness, though again, the scaling isn't too bad. The main side effect is 1) text is a little less crisp and 2) scaling makes performance a bit slower, adding a bit of lag which I've found annoying. The standard resolution for 27" displays, 2560 x 1440 (1440p, which matches the Thunderbolt Display's 27" resolution and adds 77% more screen real estate), looks pretty good. 2304 x 1236 (1300p) is probably ideal for me if I were to use a scaled resolution.

Overall, the 27" adds more screen real estate without sacrificing Retina at 2x resolution, and the scaled resolutions are pretty damn good.

Question 1 – Noticeably lower PPI? – Nope – almost as crisp as the 24" (especially when pushing it an inch further from my eyes).

Question 2 – Scaling resolution performance – Noticeable blurring. A little annoying, but the annoyance dissipates with use.

Question 3 – Lower PPI noticeable with 27"? – See Question 1

Question 4 – Do apps look way bigger on the 27" vs. the 24"? – A little larger, but it didn't bother me too much.

Question 5 – Additional space (display area) worth the trade-off? – I think so, yes. Both have the problem of blowing up the UI a bit, and the 27" a bit more, but not too much more that it's annoying as mentioned above. I lean toward this being more worth it.

Question 6 – Performance problems? – Again, some lag when driving the scaled resolutions at 1440p or 1300p.​

Comparing the two

ucFnb4B.jpg


I still haven't decided which one will be better for my use, but I'm leaning toward the 27". Reading and watching stuff is really enjoyable on this screen, and there don't seem to be many performance degradations when using this monitor. Retina (2x) looks sharp enough to cut glass on both displays. The scaled resolutions on both are a bit less crisp but they're still usable and you can always switch between resolutions when you need more clear text vs. space. So all in all, 27" is larger, costs only about $100 more, doesn't seem less crisp, and gives you a ton more space. I'll still have to take some time to decide, though.

I'll continue to update this thread with more views as I continue to use them. Hope this has been useful, happy to answer any questions you have.
 
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This is great, I've been very interested in the 27" version of this display for quite some time for home, as I use a 1440p 27" Dell monitor at work, but the 24" might be better.

The only complaint I've seen about the 27" is that the backlighting isn't great and is noticeable in dark video/games, could you take a photo of yours with just a black background? (Edit: If you don't mind, of course. If you think the backlight bleed is acceptable, I'll take your word for it, haha.)
 
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I'm assuming if you're seeing lag driving the 4k display it'll only be worse on current 13" rMBPs
 
This is great, I've been very interested in the 27" version of this display for quite some time for home, as I use a 1440p 27" Dell monitor at work, but the 24" might be better.

The only complaint I've seen about the 27" is that the backlighting isn't great and is noticeable in dark video/games, could you take a photo of yours with just a black background? (Edit: If you don't mind, of course. If you think the backlight bleed is acceptable, I'll take your word for it, haha.)

Interesting – is this only an issue with the 27" not the 24", or both? I don't see any issues with backlight bleed personally, but I also don't play many games so I probably wouldn't be able to notice it. I took a photo of the 27" (black screen) comparing it to the 24" (which is off / not connected to power). My eyes see a slight dark blue hue on the 27" (on) compared to the 24" (off), but it doesn't show up that well on the actual photo. It might be due to the sun glare, though, so I'll see if I can take a photo tonight.

PGvuSow.jpg


I'm assuming if you're seeing lag driving the 4k display it'll only be worse on current 13" rMBPs

I'm seeing the lag mostly in Chrome, which is notoriously resource-hungry – few issues in other apps. Nonetheless, yeah, I think it'll be quite a bit worse on the 13" rMBPs because of the whole integrated graphics thing. My MBP is always using discrete graphics when I have the display connected (in clamshell mode). But it might be best to see if there's anyone driving the display with a 13" MBP in the main P2X15Q thread!
 
I have the 27" model already on my hackintosh (I have real macs too and have also tried it on my 2015 rMBP 13"). It is indeed gorgeous and though I think in looks-like-1440p mode it doesn't *quite* look as good as an iMac 5K, it's pretty damn close enough when you factor in the difference in price. (And here comparing this 27" 4K with the Dell 27" 5K I'm not sure I could drive anyway, not price comparing a hack to an iMac. )

Put simply I can't bear to go back to a standard resolution display any more. I have mine set up next to my older Dell U2711, and the like-1440p mode is to match with that, but while it's still a fine monitor I feel like I'm slumming it when I look at stuff on there.

If it's laggy in this mode I barely notice it, but there are a couple of reasons for that. Firstly that what I use it for doesn't sensitise me to such issues. I write code and text, and what I love most is how crisp and clear text rendering is. That for me is by far the most important benefit of a HiDPI screen. But I'm no gamer and don't do much that involves heavy animation beyond the normal functioning of the desktop so no, it doesn't feel slow. Secondly, it's a RadeonHD 7750 driving it, and maybe it's just enough to take away the pain.

It's worth noting that in OS X retina modes are always 2x; that is the "looks like" mode is half the dimensions of the actual logical resolution. So, yes, on a 4K monitor that makes "looks-like-1080p" the default and best-performing mode. So when you select "looks-like-1440p" what I assumed was that it would just scale the User interface by a fractional amount to fit the 4K resolution. It doesn't, as you can see if you take a full screen snapshot: it is a 5K raster size, which is presumably being scaled down to fit 4K by the card.

It surprised me anyway that OS X does it that way, but I'd already been using it in that mode for a few months quite happily without noticing, so there you go. But how *much* the non-optimal scaling hurts you is probably going to be strongly determined by the GPU performance.
 
Scaling does introduce blurriness, though again, the scaling isn't too bad. The main side effect is 1) text is a little less crisp

Try going to System Preferences/General and unchecking "Use LCD font smoothing when available". This got rid if any blurriness to my eyes and everything looks crisp again. I run my 27" at 3200x1800.
 
Try going to System Preferences/General and unchecking "Use LCD font smoothing when available". This got rid if any blurriness to my eyes and everything looks crisp again. I run my 27" at 3200x1800.
Wow! This really helped a lot – thanks so much!
 
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Good comparision! Did you need to do any color calibration on either of the monitors?
 
Good comparision! Did you need to do any color calibration on either of the monitors?

Thanks! I haven't actually done any color calibration, but I no longer work with photos/graphics that much anymore so I didn't think to. Should I anyway?
 
Thanks! I haven't actually done any color calibration, but I no longer work with photos/graphics that much anymore so I didn't think to. Should I anyway?
Honestly, I'm not sure, was wondering if monitors need that since I know TVs do.
 
According to Dell:

"You can count on natural and consistent color across different mediums because each monitor is factory tuned at 99% sRGB with a color calibration factory report certifying that each monitor has a deltaE < 3. That means you get precise color coverage right out of the box at an amazing high-color depth of 1.07 billion colors. Each hue remains consistent from virtually any viewpoint with an ultra-wide viewing angle at 178°/ 178°."

Source:

http://accessories.us.dell.com/sna/productdetail.aspx?c=us&cs=04&l=en&sku=210-ADOF
 
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