can I install a ssd iii as startup disk in a sp688 (imac late 2013) or what ssd is the recommended for it?

Very good advice above. I wouldn't recommend doing it yourself. It's much easier and simpler to just purchase and install an external solid state drive. They come with a USB cable. You may have to reformat the drive, but that's easy to do. Then install an OS on it and make it your startup drive. You may then transfer your data to not, as you see fit to do. Then someday when your computer dies, which it will do, you just move the drive to a new one.

I just installed a 1TB SSD in a friend's late 2013-iMac a couple months ago. The SSD unit is from OWC as they sell an entire kit to to open the iMac, in addition to the SSD.

This SSD is designed specifically for the iMac and hence, requires no adapter, and does have a 2TB option.

https://eshop.macsales.com/shop/ssd/owc/imac-27-inch/2013-2019

Note, opening an iMac is not for those not technically skilled. It's extremely easy to damage your iMac if you don't know what you're doing. If you're not comfortable with this kind of work, take it to an authorized Mac service facility and let them upgrade it for you.

I am sorry, no, I do not have a document on it. If you wish to learn whether this is true, all you have to do is research this forum. There are likely to be hundreds of examples posted where people have done as I suggested. Incidentally, I have personally done this several times, so I know of what I speak. it is not a big deal.

Unless you’re using a Thunderbolt drive, the bandwidth of your USB connection will choke your iMac.

if you’re not comfortable doing it yourself, investigate a 3rd-party Apple service center to install an internal SSD drive. Just my 2-cent opinion at today’s market price.

I upgraded the SSD in my friends 2013 iMac in about 45 minutes, but then again, I do this often.

Internal is always better in terms of speed, but let me clarify...

Your late 2013 iMac has USB3 ports rated at 5gb/s. which is about 640MB/s in a perfect world. If you connect a SATA-based SSD drive, you might get 500MB/s given a perfect scenario. Some enclosures that use m.2 NVMe SSD's might give you the full 640MB/s over USB3, but it's a hit/miss. So you could boot MacOS from an external drive and it would run pretty well.

Here's the problem. If you connect a USB2 device into any of those ports on the back of your iMac, all the ports get reduced to USB2 speeds, and unless you remember, you'll find yourself wondering why your machine suddenly is running slow. Also, if you use other USB3 peripherals, your MacOS drive will be competing for USB bandwidth.

I just ran Blackmagic Disk Speed test on my friend's late 2013 iMac that I upgraded the SSD on, and it is running at around 770MB/s. That's full, always-available speed and your iMac will just run better and play nicer with your iMac. It will not have to compete for resources like a USB device would.

If you're planning on keeping your Mac for a while, and it's running good then upgrading the internal drive is a worthwhile investment. Another bonus is that it allows one to give the internal fans / vents a good cleaning so it runs cooler. The cooling components are probably caked with dirt/dust/lint from all those years. My friend's 2013 iMac ran about 15 degrees cooler after cleaning the fans and cooling fins which were completely blocked from dirt.

If you're planning on retiring your Mac soon, then go with the USB3 drive. Just make sure you verify that your USB ports are running at the full 5gb/s speeds. If not (due to a USB2 device), remove them all and you may have to do a SMC and PRAM reset to get the ports back to 5Gb/s. speeds.

Good luck.

DeeperDiver wrote:

Here's the problem. If you connect a USB2 device into any of those ports on the back of your iMac, all the ports get reduced to USB2 speeds, and unless you remember, you'll find yourself wondering why your machine suddenly is running slow. Also, if you use other USB3 peripherals, your MacOS drive will be competing for USB bandwidth.

If you're planning on keeping your Mac for a while, and it's running good then upgrading the internal drive is a worthwhile investment. Another bonus is that it allows one to give the internal fans / vents a good cleaning so it runs cooler. The cooling components are probably caked with dirt/dust/lint from all those years. My friend's 2013 iMac ran about 15 degrees cooler after cleaning the fans and cooling fins which were completely blocked from dirt.

If you're planning on retiring your Mac soon, then go with the USB3 drive. Just make sure you verify that your USB ports are running at the full 5gb/s speeds. If not (due to a USB2 device), remove them all and you may have to do a SMC and PRAM reset to get the ports back to 5Gb/s. speeds.

Get a powered USB3 hub that supports the UASP protocol which will help with the performance if multiple USB3 drives are connected at the same time such as during a backup. UASP also prevents USB1/2 devices from interfering with the speed of USB3 devices. Of course the external USB3 SSD used must also support the UASP protocol as well.

Edit: Actually a USB3 hub isn't needed unless you need the extra ports.