That said, for running macOS and applications, the difference between the internal SSD and an external SSD is much less noticeable than that between an SSD and a traditional HDD. The internal SSD can transfer data at about a couple GB/s.Īn external Samsung 850 Pro 512GB via a self-powered USB 3.0 docking station runs at about 400MB/s during CrystalDiskMark sequential transfer benchmark on an exFAT partition. The short answer is that you would give up a lot of performance. suggests that reviewer found a big gap between an SSD in that specific thunderbolt enclosure and the MacPro's internal PCIe SSD - Is that more likely a limitation of the case or disk inside it (in which case how can I base avoid that?), or would that be likely to apply in my case as well?īecause the maximum throughput of any port on the iMac 5k Late 2015 is only 10Gbps (Thunderbolt 2), no external storage solution can match the internal SSD's speeds. External - Let's say a Samsung 850 EVO ( ).īut if the answer is literally 'there's no performance benefit to the disk being internal that answers the real question (but I'd still love to see numbers).

Internal - Whatever Apple ships I guess.

I guess ideally what I want is something like but for the iMac 5k (so including Thunderbolt 2) and with the internal drive included for comparison.Ī comment asked what specific SSD models:

Can anyone point me in the direction of a real-world performance comparison between a iMac 5k's internal SSD and an external one (ideally one on thunderbolt and one on usb)? Basically, I want to know how much performance I'd give up by buying a smaller built in SSD and putting most data on an external.

Best internal ssd for macbook air