Time machine backup 5400 or 7200, does it matter?

[MACza]

Hi!

Long time lurker and first time poster

I will be making the switch to the world of MAC within the next day or 2 with the 2011 iMAC 21.5" entry model. Very excited and looking forward to my new toy ...

For Time Machine - does it matter at all whether you have a 5400rpm drive or 7200rpm external hard drive connected via USB? Other than it might probably take a bit longer on a 5400 than 7200?

Only reason is that the 5400 normally come in the USB powered external enclosures and the 7200rpm come with external power supply. Would just look neater with the USB powered external drive than a 7200rpm one with it's own power supply.

Any views/advice will be greatly appreciated.

PS: I will probably be back with some more noob questions regarding the MAC world - long time windows user/hacker though

 

[Jolly Giant]

it may matter for the initial (complete) backup but, since subsequent backups are incremental, you won't see much (if any) difference.

 

[MACza]

it may matter for the initial (complete) backup but, since subsequent backups are incremental, you won't see much (if any) difference.

Thanks Giant! I think I can live with the initial speed penalty and when restoring for a more clutter-free desk.

 

[harcosparky]

I won't use USB bus powered devices unless I must, such as with a laptop in the field.

Every USB drive I use on my desktop has an external power source. Even those that are bus powered are connected into a POWERED USB Hub.

I've had minor issues with those small USB bus powered drives in the past.

It would suck to get halfway through a backup and have some silly power related issue.

 

[MACza]

I won't use USB bus powered devices unless I must, such as with a laptop in the field.

Every USB drive I use on my desktop has an external power source. Even those that are bus powered are connected into a POWERED USB Hub.

I've had minor issues with those small USB bus powered drives in the past.

It would suck to get halfway through a backup and have some silly power related issue.

Really? They sometimes give issues? Hmmmm, I need the backups and restores to be very reliable - maybe I should just stick with powered ones then.

Thanks harcosparky!

 

[sth]

For large files, it doesn't really matter, but for all the small stuff (Applications, OS files, etc.) there is a noticable difference because of the faster access times. I tried both (first with a WD Green, now with a Hitachi 7k3000).

You notice it especially when Time Machine deletes old backups or is "cleaning up...". Also the first backup after a system reboot (which always takes a bit longer, even if no user files were changed) is noticably faster.

However, it's not that 5400rpm is unusable. The 7200rpm just shaves a few seconds off.

Don't use a 2,5" notebook drive unless you need it on-the-go, as they're usually even slower than 3,5" drives.
I suggest getting a 3,5" drive in a FireWire enclosure.

 

[MACza]

Thanks STH!

 

[theSeb]

It wont matter and you won't see any difference since you're talking about USB 2.0. A 5400 rpm drive is comfortably fast enough to saturate USB 2 bandwidth so the extra speed will not make a difference. Backing up over USB 2 is slow and painful.

I would second the suggestion of getting an external drive with FW800. I have not seen any of these issues with bus powered devices but normally only the 2.5" drives (gdrive mini) are bus powered and the larger capacity drives come with their own adaptors.

 

[discounteggroll]

you're paying a premium for the bus powered portable drive, but gaining the ability to not use a power cable and the ability to walk away with it rather quickly. For an iMac however, these are not really necessary and the conveniences of such aren't really seen. I would save the $ and get an external with a dedicated power supply and just tuck it away somewhere as it doesn't need to be seen. Whether or not you decide to keep it on all the time or every so often (TM will backup when the drive is accessible) is your decision, just make sure the TM is completed before ejecting and turning off the drive

 

[MACza]

Thanks for the input all - much appreciated!

I am now shopping around for a 1TB 800FW powered external HDD

 

[sth]

It wont matter and you won't see any difference since you're talking about USB 2.0. A 5400 rpm drive is comfortably fast enough to saturate USB 2 bandwidth so the extra speed will not make a difference. Backing up over USB 2 is slow and painful.

Absolutely, but even over USB2 the HDD speed will make a difference in some situations. Ever noticed how long it takes for Time Machine to back up the few few megabytes on a larger backup while the HDD is grinding like crazy? That's where the whole thing is only limited by access time, and that's where the 7200rpm drives are much better. Linear read/write speed only matters for large files.