Ext. USB 2.0 enclosure: 5400rpm vs. 7200rmp drive?

[bgc99]

If I'm using an external enclosure with USB 2.0, will I see any benefit at all by getting a 7200rpm drive vs. one of the slower "green" drives?

Thanks,
BGC

 

[Emulex]

yes you will see the ratio of 5400:7200 in difference.

we use the 7200rpm usb 2.0 to do massive linear backups (d2d) and the 5400rpm green are absolutely abysmal

 

[fffblackmage]

If I'm using an external enclosure with USB 2.0, will I see any benefit at all by getting a 7200rpm drive vs. one of the slower "green" drives?

Thanks,
BGC

You won't see any difference. Your bottleneck is the USB 2.0 connection, not the HDD itself.

 

[Blain]

USB 2 is dead, you don't want to be a loser...
Just upgrade to USB 3 (card, cable & enclosure), and go with a 7200rpm HD.

 

[sub.mesa]

yes you will see the ratio of 5400:7200 in difference.

we use the 7200rpm usb 2.0 to do massive linear backups (d2d) and the 5400rpm green are absolutely abysmal

Emulex, can you explain to me how you can recommend 7200rpm for USB2.0; where the bandwidth limit applies to about 25MB/s of real throughput?

The 5400rpm Samsung F4 does 140MB/s max; those are not abysmal speeds. Especially if you store large files, there is no reason to go 7200rpm at all; it will have lower arial density and thus lower or comparable sequential speeds to the 5400rpm disks, but 5400rpm disks use only half the power and thus generate only half the heat. For external disks this may be important, and unless you transfer small files alot, the 7200rpm part should never be noticeable at all.

So i can't think why anyone would recommend 7200rpm on USB 2.0, assuming backups of large files. The greens are excellent backup and archive disks; no reason to go for a 7200rpm disk that uses twice the power and is slower even for this kind of workload, due to its lower areal density.

 

[Blain]

Emulex, can you explain to me how you can recommend 7200rpm for USB2.0; where the bandwidth limit applies to about 25MB/s of real throughput?

He had a few too many apple martinis at the Tiki Lounge... cut him some slack.

 

[biostud]

if your motherboard has an e-sata connector then get a 7200 drive with an usb2.0/e-sata enclosure.

 

[sub.mesa]

He had a few too many apple martinis... cut him some slack.

Alright.

Fair enough.

 

[tweakboy]

That is going to be one slow external with usb conn. Soo slow firewire is slow too. If you want fast external as fast as your internal then u must use eSATA external sata enclosure unless the external hard drive doesnt support it. Just to let you know how slow USB is

I used USB 2.0 to make a image of my drive 173GB and it took 4 and half hours. I did it with eSATA connection and it took 45 minutes.

A USB external is slow as heck doesnt matter if its 5400RPM or 7200RPM your bottlenecking it. This is why you must get quality external drive with on and off button and eSATA as well as USB 2.0 and Firewire 400/800

 

[Emulex]

how bout you try it - copy a 1TB file to each and time it (teracopy will do it for you).

you will see what i mean.

and yeah esata is hella faster.

the problem with windows is that if you have policy for quick removal you save your butt - but it removes queueing (write 1 ack 1) this causes slowdown even further.

If you do policy ntfs and your usb port is unstable, too much load, you plug stuff in -you will get corruption of the filesystem- seen it so many times.

So if you use maximum write back cache over usb - you will get equal results but it will not be reliable.

i've been doing D2D2D to consumer drives for the last 4 years and i swear to god you do not want a queue depth of 32 on a usb drive.

last time was a techie came in with a boxen and dumped it on the desk. well you can imagine a busy freeagent doesn't like a thump.

very real situation.

 

[ChippyUK]

I'm quite annoyed there isn't any USB3 and ESATA enclosures (that I can find!). It would be nice to have the option of USB3 for future use, USB2 for compatibility and ESATA for my main PC (as I don't have a USB3 card). All appear to be USB3 only atm.

I believe if you're copying many small files it could beneifit from 7200 RPM but if you're sticking with USB2 and are not looking to upgrade to a faster transfer method, 5400 will be fine.

 

[bgc99]

The system is running Win XP SP3.
This external drive would be permanently attached to my parents computer as a backup drive. I built the system they use and it does have an Esata port, but I'm concerned that if the external drive is turned on after the system is powered up, it won't be seen. And I'm also concerned about what happens when they turn off the computer, will all info be written to the external drive before the system shuts down?

Thanks,
BGC

 

[kmmatney]

I would get a "green" drive - they are slower, but run a lot cooler.

 

[Emulex]

dude i've had an acomdata (fry's?) on my imac since the day i got it. firewire 400 - time machine. just leave it on, time machine does its deed once in a while, AV scans once in a while, spotlight takes a look once in a while(why?). damn thing is so loud and has a big pink light it used to wake me up.

17" imac intel core duo - the first one that's what 2006? still going.

let me remind you drives are not forgiving. i had a 120gb 2.5" ($25) and a slight drop powered off - DEAD. i was like man this thing was spun cold and heads should have been parked and its in their external case ?? dead. so isolate it on a vibration resistant boob or something

 

[JesseKnows]

You will see a difference. With modern drives the bit density for either rotation speeds is better than the sustained data rate over the USB wire. However, seeking is faster for the 7200, so overall you'd get better performance.
How much better for a real application depends on the application and how much seeking it causes.

 

[Rifter]

on large files you wont notice any diff, the 20-30MB/sec of the usb 2 bus will be the limiting factor by a long shot.

If transferring thousands of small files then the better seeks of the 7200 drive will speed things up.

 

[Emulex]

post some #'s to back that up.

 

[Soundmanred]

I've used many externals, and a WD Green and a WD Black in identical external cases transferred at the same rate (~26-28MB/s) with many different kinds of files. I could never tell the difference between them.
I go with Greens for all my external backups, and now all my data drives as well. The only "fast" drive I use is for my boot drive.