HOW IT WORKS
Choose the right hardware to fit files on your Mac
Understanding Mac storage options
Storage holds on to data on your Mac after the power is
turned off. The first thing you need to store is macOS: back in 1984 this came on a removable floppy disk, but nowadays you need it on a fixed drive from which it can be accessed as quickly as possible. You’ll then need room for documents, music, apps, photos and videos.
For the past 30 years, the startup disk inside most Macs has been a mechanical hard disk, but the balance is shifting to solid-state drives (SSDs), which use silicon chips of a kind that can retain information when powered down, unlike a computer’s main memory. These work faster, but are pricier. A terabyte of 7,200rpm hard disk costs around £65 and reads and writes data at about 150MB/sec; keeping in mind that writing is usually a bit slower and certain tasks, such as reading a lot of small files, can take longer. A low-end SSD of that capacity costs around £200 and delivers up to about 500MB/sec.
Adding an SSD makes starting up your Mac and opening apps a lot faster. In fact, because any busy Mac constantly pulls bits and bobs of data from storage into memory, and may swap it out to storage and back as you switch tasks, your system will be far more responsive if its startup disk is an SSD. Intense tasks like video editing, which need to stream data from storage in real time, benefit even more.
Ramping up the speed
The NVMe SSDs in MacBooks and iMac Pros have been ramping up in speed, with some now exceeding 3,000MB/sec. Apple connects these using interfaces based on PCI Express (PCIe), similar to – but not compatible with – the M.2 sockets on newer PC motherboards.
A terabyte of NVMe SSD will set you back around £350 at retail, or £720 at Apple’s iMac Pro build-to-order prices. (To be fair, Apple uses some of the very fastest silicon around.)
In the consumer iMac range, Apple offers hard disks as the base option, and then a halfway house it calls a Fusion Drive. This combines a hard disk with a small SSD – currently 24GB in 1TB Fusion Drives or 128GB in 3TB models – into what looks like a single drive in Finder, but is managed so that data you use regularly, including macOS, is kept on the fast SSD, and everything else on the mechanical drive. That means you get the general responsiveness of an SSD-based system, but there’s space for all your stuff, at a lower cost than a high-capacity SSD.
All MacBook versions now have only SSD storage, starting at 128GB. You may need to consider a compact USB stick or SD card, if your model has the necessary socket, to offload something like your photo collection. Accessing files from the cloud or using an
For the past 30 years, the storage in most Macs has been a hard disk, but the balance is shifting to SS D storage