Aug 27, 2015 How to Show All Possible Screen Resolutions for a Display in Mac OS X Aug 27, 2015 - 20 Comments Though it’s generally recommended to use the ‘Default for display’ screen resolution option, Mac users who connect their computer to an external display or TV may find it helpful to be able to see, access, and use all possible display. Which display resolutions are available depends on the size and capabilities of your screen. By default, most Macs will automatically be set to use the highest possible resolution they support. The same procedure applies to both the built-in screen on your Mac and any external screens you connect to it.
Macs ship with the display set at a certain resolution, and Apple defines this in the technical specifications for each model. But with Retina displays, these numbers can get confusing: there is the display’s resolution and the “looks like” resolution used on the Mac.
Resolutions on Retina Macs look like half the actual number of pixels measured vertically and horizontally because of “pixel doubling.” For example, if you have (as I do) a 5K iMac, the display resolution is 5120x2880, but the Displays pane of System Preferences tells me that it looks like 2560x1440. The Displays pane of System Preferences offers a choice of display resolutions.
That’s the default resolution, but you can change this if you want. To do so, you must first check Scaled in the Displays pane, as I have in the screenshot above, and you then see five options. These range from larger text to more space, with the Default setting in the middle. If you have aging eyes or just want to see less on your display, try one of the settings to the left of the Default option. If you want to see more on the display—with smaller fonts, menus, etc.—then try one of the settings to the right. When you hover over one of these options, the Displays pane shows a text saying that “Using a scaled resolution may affect performance.” This is because your graphics card might not be able to keep up with a higher resolution (i.e., when things look smaller), or that some of your apps may not display correctly.
The 13-inch Retina MacBook Pro has a native resolution of 2560x1600 and uses a default “looks like” resolution of 1280x800. Things are a bit different with Apple’s 12-inch Retina MacBook.
Its display has a resolution of 2304x1440, but the default “looks like” resolution it uses is not half that, but a bit more: 1280 x 800, just like the 13-inch MacBook Pro. So it looks like the same number of pixels, but on a display that’s one inch smaller diagonally. Naturally, these laptops offer other scaled options; each lets you choose from a total of four resolutions, from 1024x640 to 1440 900 (12-inch MacBook) or 1680x1050 (13-inch MacBook Pro). If you have a second display connected to your Mac, you can choose a resolution for that display, also from the Displays pane of System Preferences. Select the display in the preference pane’s popup menu, then hold down the Option key and click the Scaled button to see your options. Even more resolutions Resolutionator offers a wider range of resolutions, and also lets you switch quickly from the menu bar, or using a keyboard shortcut. Maybe you want even more choice in the resolution of your display.
If so, you can use Many Tricks’ $3. This utility lets you quickly switch resolutions without going to System Preferences, but also lets you choose from non-Retina resolutions. For example, in the screenshot below, you can see the options available on my 12-inch MacBook.
I could choose to set its display to 2560x1600; that’s not the resolution that looks like half that, which is the default, but a resolution that actually uses using every pixel of the display. Naturally, things are quite small at that resolution, so you probably won’t want to do this often, but there may be times when you want to keep your eye on several windows at a time, and only a high resolution like that will work. When I work on my MacBook, I sometimes switch resolutions. When I’m focusing on writing, I use the native resolution, which makes texts large enough that I don’t need to strain, but if I have a lot of windows open, I sometimes go to a higher resolutions to get a broader view of what I’m doing. Try changing resolutions on your Mac; you may find that it’s easier to read texts, or that you can see more, than at the default resolution.
I've got a MacBook Pro (Early 2015, OS 10.11.2) and I've also got a Dell 2209WAf monitor, which I'm using with a VGA cable. The monitor's optimum resolution is 1680x1050 @ 60Hz and RDM shows this as an option. However, when I try to use that resolution, my screen looks like this which is clearly not right (it looks impossibly pixellated and really hurts my eyes, you can barely see anything on the screen). On the monitor, it says it's displaying 800x600 when my Mac says it's displaying 1680x1050.
I've seen questions about VGA cables/adaptors etc. Asked before, but they all said it was to do with the resolution being too high. My monitor (and adaptor) can display 1920x1080 so that would appear to not be the case here. The options for the resolution in Displays all work perfectly (various ones from 800x600 up to 1400x1050 when Alt-Scaled) but then it jumps up to 1920x1080. How can I add 1680x1050 to this list, as presumably that would display clearly? SwitchResX doesn't fix this and neither does RDM, I've seen stuff about editing.plist files but that was all for Yosemite, apparently it's different for El Capitan. Any help is massively appreciated!
Okay, so I managed to work out what the issue was in the end - it was OS X's handling of the EDID data from the monitor. Windows evidently could read the data just fine, which is why it worked perfectly every time. Where Apple don't develop plug-and-play drivers for monitors (I assume) and hadn't added a profile for mine, it couldn't recognise it. In the end, it was a relatively simple fix. Here are the steps I followed (some very basic knowledge of Terminal is necessary for the second half, it's mostly common sense though).
I've spent the last 4 hours (at least) fixing that issue on macOS Sierra. The way I managed to do it is based on Dan Grove's reply to himself in this same thread, but with more DIY (thanks Dan!). Few things I think are important to understand about EDID files:. For one given screen device, EDID files are different depending on the OS. DO NOT retrieve the EDID from the computer where you have the issue (as suggested by chiara in this thread) – it did not work for me and gave me corrupted data. You will need need a computer where the screen works (typically running Windows) to retrieve the correct EDID to then port it to Mac. Now, following Dan Grove list of steps (see his post above), I would bring some clarifications as follow: Step 1 – I used a real Windows computer to do that, not a Virtual Machine.
Step 2 – There was no option to export the EDID data as an RTF file in MonitorInfoView when I did it, probably because the software got updated since. I had to click on View Lower Pane EDID Hex Dump to actually see the Hex part. Step 3 – For those who don't know what Hex is, below is a screenshot. You will have to remove the surrounding parts (highlighted in red) to only keep the Hex part (highlighted in green).
You can then copy and paste the green part in as Dan explained. You don't necessarily need to have the 3 boxes ticked, just click on Parse Edid and check if the information on the right reflect what your screen device should be – e.g you should be able to see the resolution you're trying to make work. Step 4 – This is the tricky part which got me confused.
The tutorial is asking for you to output the result of the following Terminal command in a text file ioreg -lw0, and search for various strings within the said file. Unless I'm mistaken, ioreg stands for Input/Output Register, meaning it's basically listing all the devices of your machine. However, having 2 screen devices (the native Macbook screen + the external one I was trying to make work), you need to be careful not to be mistaken with your native screen. The tutorial asks you to look for the IODisplayEDID string but my external screen did not have any in the ioreg output (which is certainly why is was not working). The correct IODisplayEDID data to create is the one we found in the Hex part, highlighted in green above.
This is the string you need to port into a mac Overrides file (just follow the tutorial if you have no idea what I'm talking about). To avoid mistakes, just be aware that the DisplayVendorID for the Apple native screens seems to be 1552.
If during the tutorial you end up using this ID, you're about to change the settings of your native screen, not the external one:) I hope this brings some clarification to the very useful steps from Dan Grove. I had a similar problem today with an iMac and a SyncMaster225BW display also with 1680x1050 native resolution. Tried SwitchResX which did not seem to work. But the problem seemed to fix itself after a reboot - the secondary display came up in native resolution. (This was after uninstalling SwitchResX.) What I actually did was reboot into recovery mode and turned off the SIP (planning to modify one of the DisplayVendorID files according to instructions that turned out to be unnecessary). I doubt turning off SIP had anything to do with it, but it's possible.
After updating to macOS Sierra I encountered same issue. As I understand it was because mac recognised it as TV instead of as additional monitor. Next steps helped me to solve the problem:. Save file from to Downloads folder. Run in terminal cd /Downloads and ruby patch-edid.rb It will generate folder with name something like DisplayVendorID-4b1f. Reboot Mac holding Cmd+R, run csrutil disable via Utilities Terminal and then reboot and log back in.
Copy generated folder to /System/Library/Displays/Contents/Resources/Overrides. Needs entering admin password. Reboot mac. It should be ok now. Repeat step 3 but running csrutil enable instead.