OSX Boot drive selection screen is slow, un-responsive and takes forever to load in Macbook Pro (early 2015)

Same issue here, noticed it in FileVault, but then realized it is there even on Boot selection section or even Diagnosis section. Disabling FileVault won't solve the issue, it will just cover it up.

I wasted a lot of time with software sides of things, reinstalling OS and all. they all didn't help. It is a Hardware issue.

I realized I have this issue once I started using SD Card reader for storing my files and extending my 128gb MBP. If SD Cards goes in, even for 1 second, and then take it out, boot is going to be slow until I do a NVRAM reset. Apple care didn't find any issue first time but second time they admit there is a hardware issue in my Macbook and they replaced it. I will report back issue returned.

You need to bring it to Apple care, and describe the issue in detail. I had to print a A4 paper with a detailed description (told them issue happen when put in a sd card and then take it out) and screenshot of diagnosis page showing SD Card error in diagnosis boot page (because for some reasons, it was randomly showing that error and apparently when I give my Macbook for first repair, it passed test 100% successfully) Reception who receive my Macbook, she didn't really reflect things I told to her to technician. She even typed issue of my macbook as "Booth up slow", you get the idea.

Yeah, you need to bring it to apple care for hardware fix and bring enough documents to prove them it is hardware issue.

Important: Do not use paragon crappy hfs+ implementation, since windows will at some point cripple your system partition! If you need HFS+ access on Windows use macdrive

First boot into single user mode (hold the S key during boot) and after some dmesg messages you should see a command prompt, do:

fsck -fy / and see if there are any errors. After the run type reboot if there were any changes or exit if nothing needed repairs.

If you have anything on your USB ports when booting, take it out - entry scan take long, especially if its some legacy USB devices. Your problem seems to be in entry scan part of booting (searching for bootable partitions of type EFI with bootflag) and/or with a device that is causing read errors. To get to the bottom of it:

Try the following first - assuming that disk0s1 is your ESP aka EFI partition, open up terminal and:

Let's check the bless output:

step 1 sudo bless --device /dev/disk0s1 --setBoot --nextonly --verbose

paste the output somewhere please so I can take a look on it. Reboot after that and see if the behaviour changes- might also help.

step 2 Let's get rid of any NVARS with boot entries and make sure they are cleared:

Launch any kind of linux from EFI (meaning booting not through MBR) - you can take Ubuntu live CD for that, after booting it, launch the terminal and do: sudo efibootmgr -v - if you get an error of not having efibootmgr command do sudo apt-get install efibootmgr (should install this package)

Once you got the efibootmgr -v (keep the output somewhere for later review)

you should see something like this:

[root@localhost ~]# efibootmgr BootCurrent: 0004 BootNext: 0003 BootOrder: 0004,0000,0001,0002,0003 Timeout: 30 seconds Boot0000* Diskette Drive(device:0) Boot0001* CD-ROM Drive(device:FF) Boot0002* Hard Drive(Device:80)/HD(Part1,Sig00112233) ...

Use the hex value to delete each entry with -B -b flag:

efibootmgr -B -b 0001

efibootmgr -B -b 0000

until it cries that there are no entries anymore. Don't worry about it, those variables are set to default each time if they are not set by your macbooks firmware - and that's what we want, we can see if the default boot device is having scanning issues or scanning issues are created by obsolete entries.

Let me know when you do this - in most cases you will be done at this point, if you won't - let me know here and we can look into it further.

I strongly recommend to use refind as bootmgr, its not native, but it does not look for Timemachine and does not calls home through wifi ;) also it gives you better options in case of troubles and you can still can use the native apple's EFI boot, refind does not care about it - its just a change in your boot order list so refind is on it. It also loads some .efi drivers for extra access and functionality at boot time, so far I know they don't collide with apple firmware.

short update: You can use nvram -p and nvram -c to clear nvram directly in macOS from terminal