Fast portable hard drives?

I typically use portable hard drives to keep backups of important things, in addition to other backups I have in place.

The two drives I have are getting old and super slow. I'm getting about 50 MB/s on one of them right now, so I want to replace it.

Looking for something with at least 2TB that is known for fast transfers but not super expensive. Doesn't matter if they have plates or are SSD, these hard drives rarely travel anyway.

Any suggestions?

Portable probably going to be more constrained by the interface than the drive.

How are you connecting them?

USB3 or C would work to be honest.

Well. IIRC USB 3.1 is like 10Gbps. That's pretty sporty. Me? I'd go the SSD route. I've had my portable spinners fail me. I've not had a portable SSD fail...yet. Prices are dropping pretty quickly on them, too, if you can afford to be patient.

USB 3.1 is now "renamed" to further confuse users. 3.1 Gen 1 is the old USB 3.0 (5Gbps), and Gen 2 is the old USB 3.1 (10Gbps).
I'd go (and went) the 3.5" drive in a USB 3.0 docking station. Any drive would saturate itself in such scenario, 150-200MB/s. I don't really trust "external" drives per se. And if I need really portable, I'd use SSDs or flash drives.

How about sticking a 2TB NVMe m.2 drive into one of the USB3.1/type C external enclosures. That is what I am going to do in future instead of buying SATA based external drives. Price is coming down all the time.

My Seagate Backup Plus Portable 5 TB transfers large files at over 100 MB/s. This is a USB-powered drive that is slightly bigger than a regular laptop HDD, probably at 5200-5900 RPM, so all things considered I am very pleased with its speed. The mains-powered drives are probably faster, but a lot bulkier and too much of a hassle, really.