Slow SSDs in MacBook Pro 13″ 2012

A friend asked me to check her MacBook Pro 13″ from 2012. It is running unbearable slow. So I’ve made a bootable copy with Carbon Copy Cloner and TimeMachine and tried to start with a fresh installation.

I’ve created an external Bootdisk with macOS 10.15 and tried to repartition and wipe the SSD. This process took already very long and I started to wonder what might have caused this delay.

This MacBook was running fine for almost two years when I’ve replaced the internal HDD with a SanDisk SSD Plus SDSSDA-480G. All the more I was wondering why it started to be so slow without warning.

I’ve found this post on where someone replaced the HDD with an SSD in the same model and it started to be very slow. The culprit should be the internal SATA cable, which isn’t either SATA3 compatible or has broken data lanes due to mechanic stress from bending or itching on sharp edges caused by the CNC milling of the MacBook case:

I’ve checked the cable and did not see any damages to the cable. So I’ve tried an old HDD on the same cable and repartitioning and installing was reasonable fast again.

I was still not convinced that the cable should be the problem, but decided to order a new cable including the IR receiver as well as the standby LED. There’s some sort of confusion about the right model number, but looks like 821-1480-A is the right one. I’ve ordered the cable from as I intended to avoid quality problems. However, you’ll get the same cable with the HDD bracket for less money from Amazon.

Replacing the cable is quite easy and can be done in less than 10 minutes.

After I’ve replaced the cable, I’ve tried the SanDisk SSD again. The installation was still very slow so I’ve cancelled the installation. Luckily I’ve had another SSD which I could test and this one installed quite fast.

So I’ve decided to replace the exchanged cable with the original cable and rebooted the Mac. I was surprised by a login screen where the default user was unknown. I’ve only created one user on that machine and it should’ve been automatically preselected. Ok, I can type that username by myself and typed the password, but I’m unable to login at all. Either password or username are wrong?!

I’ve rebooted to the recovery partition of the currently installed SSD and tried to repartition the SSD. Deletion was now slow again and failed with this error I’ve never seen before (got the error message only in German, sorry 😞):

Das Entfernen der Volumedaten zum Verhindern zukünftiger unbeabsichtigter Überprüfungen ist fehlgeschlagen (-69825).

Searching for this error lead me to a German forum, where a user has also the same MacBook and problems with his SSD. Looks like changing the SATA cable helped in this case.

After I’ve replaced the faulty SATA cable with the new one, I was able to repartition the SSD which wasn’t deletable before.

My Review of the MacBook Pro 13″ (2020) with Apple Silicon


After careful considerations and watching a lot of YouTube videos about the new Macs with Apple Silicon hardware, I’ve decided to order myself a shiny new MacBook Pro 13″ with 16GB RAM and 512GB SSD. I could compare it to my works MacBook Pro 16″ as well as my older MacBook Pro 15″ from mid 2014 and I must say, I’m really impressed.

General Things

The hardware is just great. I like the overall form factor and its small size compared to my wife’s MacBook Air 13″ 2015. The MacBooks internal speaker sound reasonable, but cannot compare to the awesome sound of the MacBook Pro 16″. But since I don’t use the internal speaker that often, I can live with the current quality.

The temperature of the MacBook is always cold, regardless of the current workload. This means, you cannot use it anymore to warm your hands in winter but also its totally quiet, even when it has an internal fan! This is a huge plus, as I’m finally having a quiet desktop again!

Another thing I like is the instant on/wakeup. This machine feels like it is an iPad. That also affects the battery life which is just crazy and unparalleled. If you’ll attach a screen it will turn on immediately. There’s no fade to black first.

M1 compatible apps

Apple Silicon is using arm64 as new architecture compared to Intel. That means all existing Intel Mac Software is run in Rosetta 2, the emulation layer for software which is only compiled for the Intel architecture. There’s already a huge list of supported software. Some apps are not working and even Homebrew has its ongoing issues, but is already useable.

Software left to check at a later time

Docker preview is already available for Apple Silicon, but is not a final stable version.

LuLu Firewall for outgoing connections is currently compiled for the Intel architecture. However, there’s already work going on in that area and I’m looking forward to it.

Visual Studio Code – Insiders available for Apple Silicon, but not a final stable version. Crashes since its last update and I’ve replaced it with the Intel version again.

Thunderbird is still compiled for Intel, whereby Firefox is already available for Apple Silicon.

StarCraft 2 is still compiled for Intel, whereby World of Warcraft is already available for Apple Silicon. Works in FullHD on external screen without sync on low Settings but high texture settings around 60-80 FPS.

Other Software I use but which is still compiled for Intel:

  • TextMate
  • Tunnelblick
  • Jdownloader 2
  • Spotify
  • Logitech Options

Using Safari as new default browser

I’ve read somewhere that Safari is so much faster on Apple Silicon compared to Chrome, so I’ve decided to use Safari as my new default browser for the time being. However, as it turns out, this was only true until Google published an Apple silicon version of Chrome enabling much faster performance.

I’ve upgraded my 1Password license from 6 to 7. This enabled the extension in Safari again, as my previous 1Password 6 license was not supported anymore.

There’s a new webfiltering extension used in Safari > 14. My Adblocker needed  updates to support this. I’m currently using Wipr from the App Store for 1,99$

Wipr’s looking good so far. It filters even most of the YouTube ads, leaving only from time to time a “Skip ad” but without content.

Issues so far

External Screen was not recognized

This is a thing I’ve witnessed on almost all my Macs I’ve used in combination with Thunderbolt docks. I’m using my Macs in Clamshell mode and only rely on wakeup by typing on external keyboard or clicking on my mouse. The Mac did not wake up and I did not have any picture visible on the screen. However, once I’ve opened the MacBook it waked instantly up and detected all external hardware including the screen.

Internal Screen resolution is wrong

The MacBook Pro wakes up after it was connected via USB-C to an external monitor with WQHD resolution. The screen flickers a little bit and the displayed resolution doesn’t fit the screen. Changing the Display options in System Settings doesn’t change this behaviour and the right side of the desktop is invisible as well as the lower part. If I take a screenshot, it will show all details. Looks like this is a Big Sur problem with external wide screens.

Bluetooth connectivity

This seems to be a well known bug. I’ve connected a Magic Trackpad and it keeps on disconnecting, regardless the real distance to the MacBook Pro. You can manually disconnect, but it will try to reconnect, even when it isn’t touched and will show a lot of annoying system notifications.

Festplattenaussetzer auf dem MacbookPro 13,3″ verhindern

Ich habe mich ja schon vor einiger Zeit mal darüber aufgeregt, dass ich in meinem 13,3″ MacbookPro extremste Probleme mit der Festplatte hatte. Das äußerte sich z.B. in einem System, das nicht mehr auf meine Anfragen reagiert, aber nach etwa 30 bis 60 Sekunden wieder normal weiter läuft und tut, als ob nichts passiert wäre.

Mittlerweile habe ich das bei mir an anderer Stelle nicht empfohlene EFI Update für 3GBit Sata installiert und hatte noch immer die Probleme.

Festplattenaussetzer auf dem MacbookPro 13,3″ verhindern weiterlesen