I have an external HD with USB 3.0, which I'm attaching to my new iMac using a USB to Thunderbolt 3 converter.
Will data transfer this way be slower than if I had a drive with a Thunderbolt 3 cable? I just got a new iMac and don't want to upgrade my drive, if its not necessary.
macOS Sierra (10.12.5)
In theory, Thunderbolt 3 will be significantly faster than USB 3.
In practice, it may not make any difference as far as what you see while you're working.
What kind of data are you storing on the external drive, and what kind of work will you be doing with it?
It's mostly music, videos, photos. I don't do a ton of video editing, but I will do it occasionally. I do a decent amount of photo editing and organizing, though I'm not a professional.
Will it make a difference if I get a drive with a Thunderbolt 3 port, instead of USB 3 connected using a USB to Thunderbolt 3 converter?
And if I'm going to do that, will getting a RAID make a performance difference, or will it be negligible given what I plan to do with it?
John,
You will get the same performance from your Hard Disk Drive whether you use USB 3 or Thunderbolt 3.
The choke point in all hard drive setups is the hard drive controller, the interface between the SATA connector and the storage platters in your HDD. USB/Thunderbolt cable speeds don't matter when your HDDs are only capable of read/write speeds at around 100MBps each. In other words, there is no significant difference between plugging your external USB HDD drive in your USB port versus going through the adapter to Thunderbolt.
Yes, you can get a NAS, more Hard Disk Drives, and set your 7200rpm drives to mirror in Raid 1 or Raid 10. This will double your read speed, but your write speed won't improve. The only real difference for you is that Thunderbolt will attempt to auto-recover when re-connected after an accidental disconnect. USB won't. Thunderbolt will also daisy chain from device to device where USB must split through powered Hubs.
If you really want to see a difference, take the big step into Solid State Drives. The basic SSDs of today have throughputs of 400MBps-500MBps. Yes, they cost more per gigabyte, but with a good NAS, you can replicate one large HDD with several small affordable SSDs in Raid 5/6. This costs a little more, but it is faster and more reliable.
There is one catch:
If the internal drive in your computer is an HDD, you won't feel the full difference between an external HDD and an external SSD. Your internal HDD isn't able to receive data as fast as an SSD can send it. If you really want to feel the difference, replace your internal HDD with an SSD. The first time you run your operating system on an SSD, you won't go back.
You can also take your USB 3 HDD to a computer operating on an internal SSD. Try transferring files between your external USB HDD and the internal SSD. Then try transferring between an external SSD and an internal SSD. It won't matter if the external SSD is USB or Thunderbolt. You will instantly see the difference.
someoneotherthanyou wrote:
...
There is one catch:
If the internal drive in your computer is an HDD, you won't feel the full difference between an external HDD and an external SSD. Your internal HDD isn't able to receive data as fast as an SSD can send it. If you really want to feel the difference, replace your internal HDD with an SSD. The first time you run your operating system on an SSD, you won't go back.
..
If you create a fully bootable external SSD and run your system
off of it, it will be nearly as fast as an internal SSD and a much easier
solution than ripping apart an iMac to replace the HDD. Of course,
even running your system off of it, any access to any HDD will will
be limited by the HDD.
.
woodmeister,
Yes, of course, but you should be telling John this. I am already using SSDs.
USB 3.0 vs Thunderbolt 3 - how much speed difference is there for a 7200RPM external HD?
