Some apps and other code doesn’t appear to run faster on M1 chips, and some even runs more slowly. Could this be a result of it not using the best acceleration for vectors and matrices? | Continue reading
What are all those files and folders doing inside an app? Which can you safely change to customise an app? Why all the helpers? | Continue reading
Does your M1 Mac run more slowly when it’s on battery power, or with Low Power mode enabled? An exploration of effects on its CPU cores provides an unexpected answer. | Continue reading
The E cores on the original M1 and M1 Pro chips appear to be managed quite differently, with respect to the performance of background processes at low QoS. | Continue reading
Obtaining estimates for individual P and E core performance of processes run mainly in an ALU and those using floating-point and SIMD gives further insight and confirms the cores haven’t chan… | Continue reading
Fed up with the Flying Pointer? Tired of the oldest Universal Bug in Finder Column Widths? Want updates from the App Store? These are some of the annoyances in 12.0.1. | Continue reading
Many folders have them. They’re so invisible that you can’t even see them when you show hidden files. And the only way you know they’re there is when they cause problems. | Continue reading
How does macOS load processes onto the cores in M1 series processors? Are its policies similar between the original M1 and the M1 Pro? | Continue reading
Geekbench 5 scores for the M1 Pro are around 2800 single- and 12500 multi-core. Do they represent maximum performance, though? | Continue reading
How this memory leak probably occurs, which apps it affects, and what you can do to avoid it completely. | Continue reading
Tab groups make it easy and convenient to have dozens of pages open at the same time in Safari. But that comes at a price – they could run your Mac low on memory. | Continue reading
New for Monterey: Disk Utility now offers complete features for the management and maintenance of snapshots. | Continue reading
Is Apple going to meet the promises it made a year ago, to protect its users around the world from the risk posed by its online signing certificate checks? | Continue reading
From the IBM PC XT with its 10 MB hard disk to a SoC which moves data to its SSD at over 7 GB/s. How CPUs interface with peripherals. | Continue reading
The P cores in the M1 Pro/Max CPU are managed in two groups of four, sparing load on the second group, and distributing it unevenly within each group. Its two E cores outperform the four in the M1 … | Continue reading
How APFS, the boot volume group, hashes, and Secure Boot all combine to guarantee the integrity of your system, and save you trouble and work. | Continue reading
Explore running test code of different types on the different cores in your M1 Mac. Provides insight into how your Mac performs, rather than just how fast it is. | Continue reading
A detailed walk through the log shows Safari 15 checking Safe Browsing, phishing sites using ML, and performing trust evaluation of certificates. | Continue reading
Did you think it was only old Mac OS X affected by the Let’s Encrypt certificate expiry problem? No, it’s Safari wherever you can use it. Here’s how to deal with it. | Continue reading
As Apple silently drops Mojave’s support, it releases a security update to iOS 12, which was originally released a week before Mojave. And its entire AirPort range also seems unsupported now. | Continue reading
Unofficially, each major version of macOS gets a year’s full support, with bug and security fixes, then 2 years of security updates. Is that how it works? | Continue reading
Apple seemed reluctant to provide a full installer and IPSW image for 11.6. How does that affect those staying with Big Sur for the next year of security updates? | Continue reading
With Big Sur 11.6 reaching the end of the year’s cycle, it’s time to take stock of just how much we had to download to keep it up to date. | Continue reading
What are the penalties in real-world use for running your code on Icestorm cores, using around 10% of the power used by Firestorms? | Continue reading
Memory, support for multiple external displays, bootable external disks, macOS updates, kernel panics, more ports, and more choice of macOS to install are on my list. | Continue reading
Summary and links for the latest information about what’s in the current M1 chip, from differences in caches between cores, to the Matrix Coprocessor and Fabric limitations. | Continue reading
How ARM64 uses its special SIMD registers in lanes, and how they can be loaded with and without de-interleaving. | Continue reading
Apple hasn’t trusted us with the knowledge of what’s in macOS 11.5.2 update, but expects us to trust it not to abuse its checks on CSAM. | Continue reading
In the original JPEG image, the yellow and red are clearly distinguishable. By the time they’ve been rendered, they are hard to tell apart. Unless you’re colour-blind. | Continue reading
Nine months ago, Apple undertook to make changes in the way in which macOS checks its OCSP service for certificate revocations. Has it changed anything yet? | Continue reading
Three recent WWDC sessions extolling Apple’s “extensive reference material” and Xcode can’t find anything on these rich and extensive libraries. | Continue reading
In macOS 11.5.1, Apple has squeezed a thimbleful of a patch into a ten-gallon can of update, more than 99% of which is overhead. | Continue reading
The macOS 11.5.1 update fixes a serious vulnerability, but does it really take 2.2 GB (Intel) or 3.1 GB (M1) to fix what could only have been a few MB at most? | Continue reading
When should we expect macOS 11.6? When will Monterey be released, and when will the next Apple Silicon models be announced? Here are some wild guesses. | Continue reading
Haven’t Macs and macOS changed over the last six years? Here are fictitious diary entries to illustrate the deep-seated changes. | Continue reading
Floating point numbers are very different from integers, but are loaded and stored much the same. Conversion between registers, including to and from integers, is complex. | Continue reading
M1 Macs have an elaborate system of keys and certificates which allow the installation of second operating systems, as well as the primary OS, based on Ownership. | Continue reading
Where code can make simple selections according to a conditional test, it may be possible to eliminate branching and ensure rapid execution. | Continue reading
Many processors like the ARM64 have instructions to perform fused multiply-add operations. Do they deliver reduced error and better performance? | Continue reading
The primary admin account on an M1 Mac is its Owner, responsible for authorising the installation and use of second operating systems. Here’s what can go wrong with Ownership. | Continue reading
macOS 11.5 will be available in a few days. Should you risk upgrading? Here are some of the major issues which you need to consider when deciding and planning any upgrade. | Continue reading
Most hard disks become increasingly likely to fail after 3 years. All Time Capsules are now in that zone, and should either be replaced or have their hard disks replaced. | Continue reading
Basic integer arithmetic – add, subtract, negate, multiply, multiply-and-add, and divide – in their many variations. With some catches for those more used to high-level languages. | Continue reading
Explaining the LDR family of instructions for loading registers, MOV for moving one register to another, STR for storing to memory, and SXTx/UXTx for filling a register with smaller data types. | Continue reading
Management of kernel extensions has changed significantly in Big Sur and later. This overview for users contrasts kexts with user-level extensions which are replacing them. | Continue reading
How conditional branching can slow modern processors down badly, comparing assembly code with that generated by Apple’s Swift compiler, and some puzzles. | Continue reading
A wedding and two major commissions: a series of large wall paintings on the Life of the Virgin, and his first 9 cartoons for tapestries, on the theme of hunting. | Continue reading
Don’t use Unicode normalised Form C names for volumes in Disk Utility, as they cause havoc, and prevent Spotlight from indexing volumes. | Continue reading