Archive for January 14, 2020

Tuesday, January 14, 2020

Low Power Mode for Mac Laptops

Marco Arment (tweet):

In light of today’s rumor that a Pro Mode may be coming that seems to offer benefits in the opposite direction, I wanted to re-make the case for a Low Power Mode on macOS — and explain why now is the time.


Apple’s customers don’t usually have control over these balances, and they’re usually fixed at design time with little opportunity to adapt to changing circumstances or customer priorities.


Turbo Boost Switcher Pro relies on a kernel extension that’s grandfathered into Apple’s latest security requirements, but it can never be updated — and when macOS Catalina loads it for the first time, it warns that it’ll be “incompatible with a future version of macOS.” I suspect that this is the last year I’ll get to run the latest OS and be able to turn off Turbo Boost at will, making all of my future laptop usage significantly worse.


Update (2020-01-24): John Gruber:

Note too that iOS’s Low Power Mode is for iPhones only — iPads don’t have it. That bodes poorly for the odds of a Low Power Mode for MacBooks — it feels like a feature Apple believes is needed only for phones.

Jason Snell:

I’m all for the idea of a low-power mode for Macs, and it’s a bit perplexing to see Apple prioritize turning off all battery-saving features and cranking the fans over letting users maximize battery life.

I do have a wacky idea, though. (You knew I would.) What if Apple used the introduction of Pro Mode to adjust the default performance settings of macOS laptops?

Macro Arment:

My guess for why iPad doesn’t have Low Power mode:

An iPad’s CPU, where much of LPM’s savings comes from (downclocking, avoiding background tasks) is a much smaller percentage of its power usage than its (way larger) screen.

Same isn’t true for laptops.

See also: MacRumors.

Kyle Howells:

A real “Pro Mode” would disable the ridiculous sandboxing, permission dialogs and restrictions.

But developers wouldn’t really be able to use it, if they wanted to dogfood their own apps.

Jeff Johnson:

I’ve learned that Apple engineers have internal tools which allow them to delete macl xattr as well as to bypass other Catalina privacy and sandbox protections without rebooting and disabling SIP.

Inside Apple they don’t suffer the same problems as external users and developers.

That would help explain why they aren’t catching the security/privacy protection bugs before release.


The Security of Safari Extensions

Jeff Johnson:

Every Safari extension that runs JavaScript — in other words, almost every Safari extension — will have these same warnings, so what are users supposed to do with the warnings? Avoid Safari extensions entirely? Then why does Apple provide a developer API for Safari extensions, if they aren’t meant to be used? Why are Safari extensions available in the Mac App Store? Why does Apple advertise that they’re available in the Mac App Store? You get the feeling that different teams within Apple are not on the same page here, and they’re giving unhelpful mixed messages to users.


In general, my view is that you shouldn’t install software on your Mac unless you trust the developer. You can’t rely on the system to protect you from malicious software, because there are always vulnerabilities and ways to get around the system.

It’s a recurring theme. Without the scary warning, Apple gets blamed for any problems. With the warning, developers blame Apple for scaring customers away from their products, and if anything bad happens everyone blames the customer for ignoring the warning that they had no way to evaluate.


Aerial Screensaver and Catalina

Guillaume Louel (via Tanner Bennett):

In macOS Catalina, 3rd party screensavers are now running in a sandboxed container which limits everything. As of right now there are no workarounds for many of the restrictions.


Aerial can only write in the legacyScreenSaver.appex sandbox container, which means in Catalina, JSON files and videos can only be downloaded in ~/Library/Containers/ Support/Aerial. Aerial can still read (only) the rest of your system disk so you can still store the videos in another folder after they are downloaded by manually setting the Cache. But Aerial cannot download videos to this cache.


Your cache may be wiped by the Catalina installer


[Because] a screen saver is not an app (we are a plugin run by legacyScreenSaver) we can’t ask for entitlements for, say, accessing filesystem.


Some (not all) of Apple screensavers are now bundled as an .appex too, with their own permissions. As far as I know that format is still not documented to this day nor available to 3rd parties.


Update (2020-01-24): Dennis:

Yesterday I thought it would be a good idea to clean up my certificates under Turned out I broke everything since it broke the notarized binary. Guess I need to pay forever too support it.

The Dark Side of Dark Mode and Night Shift

Adam Engst (tweet, Hacker News):

Unfortunately, Apple’s marketing claims about Dark Mode’s benefits fly in the face of the science of human visual perception. Except in extraordinary situations, Dark Mode is not easy on the eyes, in any way. The human eyes and brain prefer dark-on-light, and reversing that forces them to work harder to read text, parse controls, and comprehend what you’re seeing.


In the scientific literature, black on white is called “positive polarity,” whereas white on black is called “negative polarity.” Numerous studies over decades of research have found that positive polarity displays provide improved performance in a variety of areas.


When there’s a mismatch between the two—the screen is too dim outside or too bright inside—it’s hard to look at. That’s why Apple implemented automatic brightness control in iOS (find it in Settings > General > Accessibility > Display Accommodations) to reduce the screen brightness when you’re reading in a dark bedroom and increase it when you’re trying to take a picture on a sunny day.

I haven’t personally found any use for Dark Mode on my Mac. I don’t like the way it looks, and it feels like it slows me down. I have always preferred light text on a dark background for code, though. My sense is that this is not because I like light-on-dark better than dark-on-light for the primary text, but rather because most of the other colors work better on a dark background. With multi-color themes, the secondary colors tend to be easier to see on a dark background.

I don’t like how Dark Mode looks on iOS, either, except that I’ve always preferred Tweetbot in dark. I also like to run OmniFocus in dark so that the screen isn’t so bright if I’m making a note at night. Automatic brightness control just doesn’t cut it.

I continue to like Night Shift.

Jonathan Wight:

Giving on up dark mode.

Don’t like.

I get double vision due to my eye condition on most text and in almost all dark mode implementations it’s far more pronounced.

John Gruber found that Dark Mode helps with his eye condition.

Chance Miller:

These features are designed to change the temperature and color of your display based on what time of day it is. New research suggests, however, that features designed to reduce blue light before bedtime might not be as effective as initially thought.


Update (2020-06-05): Isaiah Carew:

i’ve been using the pseudo-dark mode in the accessibility controls for years. on the mac too.

i don’t care what the studies say, it is one of the few things that has made a noticeable difference in my dyslexia.

dyslexic fonts and retina monitors are pretty great too.

Update (2020-11-27): Kev Quirk (via Greg Hurrell, Hacker News):

According to the reading I’ve done, dark mode isn’t easier to read and it doesn’t prevent eye strain. However, in very specific circumstances it can improve battery life.

I’m sure there are people out there who genuinely need dark mode for a specific health condition. For that reason, there will continue to be a dark mode on this site.

But if you’re like me, and just prefer dark mode, you may be making things more difficult for yourself and actually damaging your eyes in the long run.