I have a mid-2017 iMac that we purchased in September to replace our ageing mid-2010 iMac. The thing is this iMac feels slower than our old iMac. My husband and kids complain all the time too, so it’s not just me.
New iMac Specs:
- Mid-2017 iMac
- Retina 4K 21.5 inch
- 3.0GHz quad-core Intel i5 CPU
- AMD Radeon Pro 555 with 2GB Memory
- 1TB Hard Drive
- 8GB RAM
- macOS Sierra 10.12.6
Old iMac Specs:
- Mid-2010 iMac
- 21.5 inch
- 3.06GHz dual-core Intel i3 CPU
- ATI Radeon HD 4670 with 256MB Memory
- 500GB Hard Drive
- 8GB RAM
- Mac OS X El Capitan 10.11.6
Obviously the new iMac has equal or better specs all round, so why does it feel so slooow?! Seems to take ages to boot, run apps, etc.
I know I can’t upgrade the hard drive or RAM now, and I can’t run El Capitan, but is there anything else I can do? Reinstall Sierra? Maybe upgrade to High Sierra? Something else?
Best Answer
Why does it feel so slow?
Your iMac has a 1TB 5400rpm SATA Hard Drive and this is what’s causing the bottleneck. Your mid-2010 iMac would have had a 7200rpm Hard Drive. To fix this you really need to address this bottleneck.
The 'easiest' solution
Since your iMac has two Thunderbolt 3 (USB-C) ports that support speeds up to 40 Gbps (via Thunderbolt) and 10 Gbps (via USB 3.1 Gen 2), the easiest solution is to use an external SSD that’s connected via one of these ports and to install macOS on that and use that drive as your main boot volume. However, you need to ensure that:
Both of the above are critical if you’re wanting to improve speed. However, you’ll probably find Thunderbolt models are too expensive, so opt for USB-C / USB 3.1. Do not get confused by USB 3 - this is not the same as USB 3.1. And remember, it needs to connect to one of the two Thunderbolt ports (not one of the USB ports).
Some examples of the types of external drives I mean are:
Once you have the drive you want, you will need to install macOS onto it and migrate your data.
NOTES:
Let me know if you have any questions or would like to chat about doing an internal upgrade.
Case study
Today (24 Jan 2018) I installed macOS Sierra 10.12.6 on an external SSD (specifically a 500GB Samsung T5) and did some comparison tests to try and provide an indicative idea of the type of speed improvements you could expect.
The tests were performed on the same model iMac as yours (i.e. mid-2017 Retina 4k iMac with 8GB RAM, a 3.0 GHz quad-core i5 CPU and a 5400rpm SATA hard drive). Obviously, your results will vary depending on the software/login items/fonts/kernel extensions you have installed.
Below are the results of my testing.
Testing notes:
1. macOS and all apps were installed on the external SSD.
2. All tests performed three times and the results averaged.
3. Each time tests were run, they were run after a fresh reboot.
4. For Test 6, although the Photos app was installed on the external SSD, the 380GB Photos library was stored on the internal 5400rpm SATA hard drive.