One thing to note is that you don't need any of these high-end systems if you just enjoying editing home video in iMovie. If you just want to edit video clips you've recorded on your iPhone, something basic like a Mac mini 2.6GHz i5 is perfectly capable of handling most basic video tasks, including light editing in Final Cut Pro X.
How fast does my Mac need to be for audio recording and editing?
Audio recording and editing doesn't require the latest Intel i7 Mac. So you can get away with a much more lightweight model, like the Mac mini or a MacBook. A mid-range Mac mini (£569) is perfectly good for audio recording, and with 4xUSB 3.0 ports, 2xThunderbolt 2, audio in, audio out and an SDXC card slot, the Mac mini has a great array of connections. This makes it ideal as a recording device.
The entry level 1.6GHz 12.5in iMac is also a good choice if you want an all-in-one system for audio recording. However, many audio recording engineers prefer a MacBook Pro because they can carry it to studios more easily. You don't need the Retina Display model, and we'd be tempted to go for the 13-inch 2.7GHz model (£999). This has a good range of connections, including 2xUSB 3.0 ports, 2x Thunderbolt 2 ports and 1x HDMI out port.
How fast does my Mac need to be for gaming?
Gaming itself covers a wide spectrum of experiences. However, typically gamers want the fastest system possible. If you're into gaming you'll probably want a fast Mac, but you don't gain much from the i7 processor. Instead, it's better to focus on the CPU with a faster clock rate and combine it with a machine with a separate graphics card (this is separate from the Intel CPU, many Macs combine the CPU with an Integrated graphics card).
Essentially, you need a 27in 5K iMac or 15-inch MacBook Pro with Retina Display (the top of the line model of each with an AMD Radeon R9 M3905 or AMD Radeon R9 M370X respectively). Couple this with at least 8GB of RAM and 256GB SSD/1TB Fusion Drive and you've got something more than capable for Mac gaming.
How fast does my Mac need to be for Art and design work?
Everybody wants to be able to design faster, but you don't need an Intel i7 for Photoshop as it doesn't really get much from it. So we'd focus on picking one of the cheaper models and taking the RAM up to at least 8GB and replacing the stock drive with a fusion model (if it isn't already). If you get a mid-range Mac Mini (£569) and add a 1TB Fusion Drive (£160) you get a great little design machine for £729. You can now spend any other money on a decent display and any additional accessories you might need.
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