Does RPM or interface make more of a difference when using an external harddrive?

Jskid

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Feb 12, 2011
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Does RPM or interface make more of a difference when using an external hard drive? Would you rather USB 3.0 and 5400rpm or USB 2.0 and 7200rpm?
 

Wall Street

Senior member
Mar 28, 2012
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On a spinning platter drives, RPM and platter density matter more than interface if the drive is SATA.
 

Cerb

Elite Member
Aug 26, 2000
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Does RPM or interface make more of a difference when using an external hard drive? Would you rather USB 3.0 and 5400rpm or USB 2.0 and 7200rpm?
I'd rather have neither, but a USB 3.0 5400RPM drive will transfer files faster than a USB 2.0 anything. USB 3.0, until you saturate it, isn't too much slower than native, while USB 2.0 is very slow to access files. If I can, I use a 100Mb network to back up files, FI, instead of a USB 2.0 drive, because it's actually faster, with all the small files in most user's profiles.

So, no, don't worry about RPM nearly as much as the interface. Density, RPM, and firmware tweaks can make a difference for the drive's performance, but USB 2.0 is a ball and chain.
 
Last edited:

Hellhammer

AnandTech Emeritus
Apr 25, 2011
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USB 2.0 = ~35MB/s in real world
USB 3.0 = ~280MB/s since the SATA to USB 3.0 bridge is most likely SATA 3Gb/s (or the actual drive is SATA 3Gb/s)

High-density (+1TB) 3.5" 5400rpm drive: ~100MB/s
High-density 3.5" 7200rpm drive: ~150MB/s

So, USB 2.0 will be the bottleneck regardless of the drive inside. Hence a USB 3.0 drive is a much better option, even if it means a 5400rpm HD.
 

Wall Street

Senior member
Mar 28, 2012
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On a spinning platter drives, RPM and platter density matter more than interface if the drive is SATA.

Wow, I totally didn't see "external" there. If it is external, USB 2.0 drives will be slowest regardless of RPM speed or platter density. For any other interface (eSATA, USB 3.0, Thunderbolt), throughput will be limited more by the rotation speed and platter density than by which among those interfaces is used.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
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USB3 matters more than 7200rpm.

This. But, for my external drive I use eSATA. It's been mature for years and is about 5 times faster than USB 2. I don't have USB 3, and probably will not until a new computer bubbles up.
 

BFG10K

Lifer
Aug 14, 2000
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For external it’s the interface, by far. USB2 is really slow for I/O and even USB3 will bottleneck some things because of its extra latency over eSATA.
 

sanityvoid

Junior Member
Nov 23, 2010
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I didn't feel like starting a new thread on this, but I have a continuation/new angle on it.

Buying a USB 3.0 external 2.5"

Which is better in this scenario?

Both USB 3.0

500 GB 7200 RPM vs. 1 TB 5400 RPM???


I'm pretty sure of the answer but I just wanted to confirm something in my brain.

Thanks for the help!!!
 

Blain

Lifer
Oct 9, 1999
23,643
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I didn't feel like starting a new thread on this, but I have a continuation/new angle on it.

Buying a USB 3.0 external 2.5"

Which is better in this scenario?

Both USB 3.0

500 GB 7200 RPM vs. 1 TB 5400 RPM???


I'm pretty sure of the answer but I just wanted to confirm something in my brain.

Thanks for the help!!!
If you have 600GBs of data to store, I'd pick the slower 1TB HD.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
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And if you have 250GB or less data to store, I would ick 7200 RPM 500GB drive. :)

See - a logical case can be made either way until you nail down the assumptions.
 

sanityvoid

Junior Member
Nov 23, 2010
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66
Well I guess my thoughts were going along the lines of bigger platters are somewhat faster than smaller platters but RPM speeds are a/the biggest factor. I guess I've never seen studies which say which is faster.

Larger platters or more rpm. Logically, it would seem to me that RPM rule, but I don't know.

That was really what I was wondering.

Data is not a huge factor. I don't want a monstrous external, but I was plenty sure I wanted the 2.5" factor, not 3.5". Prices get pretty crazy fast on the smaller size.

Thanks for the replies.