Question about external portable drive speeds (rpm, usb vs thunderbolt)

[julianw]

My main external portable drive (G-Drive mobile, Firewire, 2 years old) just took a dive so today I picked up a Lacie Rugged 1 TB Thunderbolt drive. I am a photographer and therefore am constantly loading many GBs of data onto my portable drive and working off of it, so I can keep my internal drive clear. (retina macbook pro)

I did a couple speed tests with the Lacie drive when I got home and was very disappointed that it didn't seem like a big leap over Firewire. I had a 7GB folder on my internal drive and wanted to compare the transfer via Thunderbolt, then via USB 3. I copied the folder to the drive to see the write speed, then copied back to my computer to see the read speed. Then switched connection type. My results are as follows:

Write 7GB to drive:
______________Transfer (sec)___Speed (MB/s)
USB 3.0.............69....................104
Thunderbolt.......67....................107

Read 7GB from drive:
______________Transfer (sec)___Speed (MB/s)
USB 3.0.............120...................60
Thunderbolt.......67....................107


I tried the same test via Firewire onto another G-Drive Mobile and it was about exactly half the speed of Thunderbolt. I know the numbers they say on the back of the box are never real but I expected a lot better than this. Am I missing something? Is this Lacie drive slow for some reason? (This drive is 5400rpm whereas the Firewire G-Drive is 7200rpm). Do RPMs make that much of a difference? My need is more for drive size rather than speed, so SSD is not an option, I'm just curious where the slowest link is in this process.

I would appreciate any info and thoughts. Thank you!

Julian

 

[julianw]

Not sure how I didn't see this in my quick research before posting but I just found a page where someone asks the same question and people wrote back saying the bottleneck is the drive.

"The fastest 7200RPM 3.5" drives are around 140MB/s sequential write. Most of the time you won't get that high. The 5400RPM drive is below 100MB/s read or write."

and apparently SSD are about 500MB/s.

So my next question is, what the heck is the purpose of selling a 5400rpm hard drive with thunderbolt if the drive itself doesn't even saturate a usb3 connection??

 

[popatim]

Actually your other bottleneck is the firewire port. Its designed to maintain a more constant speed rather than fall into max & minimum transfer speeds