Portable Hard Drives

[archaeo]

I'm looking to purchase a portable (1TB+) USB hard drive to store my dvd collection. I'd like to find something that I can plug in to a laptop (I travel frequently) to view movies while away from home. I'd prefer that it does not require a separate power cord, since sometimes it's not available. I do see a lot of choices out there, so I wanted to see what others are using for dvd storage/viewing. Some of my questions:

What do you see as an adequate baseline for transfer speed for viewing/transferring? I've seen a capability anywhere from 5-25 MB/s with USB drives.

Do most of these portable drives require a power cord, or can they run independently through USB power?

Ability to format for NTFS

Reliability & Durability. Want something that will stand up to being moved around, but not abused. This HD also be long term storage for my collection.

Thanks for any input.

[Inventive Software]

Nothing that large is available that's just USB powered, biggest you can get is around 500GB. The 1TB drives need a power cord. Ordinarily they'll be formated FAT32 and you can then re-format to HFS or NTFS or ext3 depending on the OS you use it for most (my WD Elements 640GB was FAT32, I reformatted to NTFS).

[archaeo]

Hmm, 500 Gb is not a bad compromise for having complete portability w/out need for external power.
How about USB transfer speeds? Do most of these drives have adequate speed for what I'm looking for? Any issues to be aware of?

[Blue_MiSfit]

You'll be fine :)

~MiSfit

[archaeo]

appreciate the feedback

[Ma-Xell]

I have a Fujitsu Siemens 500GB USB external hard drive.
It does need external power :( and the avg transfer rate is in the mid 20s (MB/s).
I have captured SD Huffyuv in realtime with it, so its ok. The eSATA ones are the best now
they don't lose transfer speed.

[Blue_MiSfit]

Right.

Of course, if something is bus powered, it's a 2.5" model, which means (usually) that it's a bit slower.

3.5" drive, connected via eSATA is the way to go for max performance :)

~MiSfit

[archaeo]

resurrecting this... but has there been any significant advances in transfer speed from these portable (USB powered only) HDD?

more specifically - How's does the seagate freeagent go (500Gb) look? Anybody using it for video playback into their HDTV?

I ended up going with a 1TB 3.5" w/external enclosure, but the size/portability of the 2.5" is drawing me back into the fray.

[CWR03]

Whether or not it will work for you depends greatly on the files you'll be viewing. A BluRay ripped and muxed directly into an MKV file will require a much greater data transfer rate than a 2-hour movie compressed to a 700 MB AVI. Once you figure out how much data per second you'll be transferring by watching videos from an external hard drive, it's just a matter of finding one with an adequate rating.

[archaeo]

Whether or not it will work for you depends greatly on the files you'll be viewing. A BluRay ripped and muxed directly into an MKV file will require a much greater data transfer rate than a 2-hour movie compressed to a 700 MB AVI. Once you figure out how much data per second you'll be transferring by watching videos from an external hard drive, it's just a matter of finding one with an adequate rating.

Yes, I plan on having bluray compressed (via x264) to an mkv file as part of the mix. Bitrates in these are around 8-20 Mbt/s.
From what I understand uncompressed bluray requires up to 40Mbit/s. I may have a few of my titles in uncompressed form.

So, what are these portable drives transferring at? I can't seem to find that info (easily) in their online specs, but I do see forum reports of only 20Mbit/s?



thanks

[kypec]

I think that even most demanding bitrate-wise clips are far below real throughput of USB 2.0 HiSpeed limits.
Given that 480Mbps bandwidth is used in full-duplex mode, you still get 240Mbps for single data transfer direction overall.
Take away overhead+bus management (33%) and we're still at 160 Mbits per second.
I doubt you'll ever find a video+audio streams that would exceed 160 Mbps.
If a portable USB 2.5" HDD can't deliver ~30 MB/s transfer rate (for large files of course, not many small ones) then it's a lousy product which has no place in my life.

Conclusion: choose a model which fulfills these requirements or get a refund. ;)

[archaeo]

I'm going to go ahead and order the seagate freeagent go 500Gb to test it out for strictly video storage and playback. It seems that the specs do suggest that the transfer rate will be more than adequate. I'll be running it through a Western Digital Media Player into my HDTV, or to be connected through either a PC or laptop.

Next to having my concerns addressed regarding adequate transfer speed and reliability, I'm primarily drawn to the portable drives for the fact that they do not require a separate power cord. I like the fact that the USB will provide power to the Disk. This is very convenient when travelling, etc,.

If anyone has firsthand experience with this drive with the playback of HD files, please provide any feedback. I'll report back when I have some time with it myself.

[StainlessS]

@archaeo

A 2.5 HD may need to occupy 2 USB ports, particularly higher capacity
drives, to adequately supply power for the device, hopefully you have
sufficient available ports.
Note that a drive coming together with an additional USB power connector
does not say one way or the other that it will run without it. I have
3 x 2.5 inch devices, two of which run without, and one that does require
the extra lead. The extra lead is usually supplied anyway for situations where
a power outage would be disasterous, eg bios flashing. :)

[mariush]

I'd recommend getting an enclosure such as this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16817173043

For extra compatibility you might also want to think about one with Firewire which should give you more stable speeds compared to USB but USB is found anywhere so it should be good enough.

[Ghitulescu]

I think firewire sits now near SCSI.

Most modern laptops and external HDDs have an eSATA connector, which is faster not only because it's SATA but also because the need for intermediate protocols (USB, iLink etc.) has been eliminated.

[archaeo]

I think that even most demanding bitrate-wise clips are far below real throughput of USB 2.0 HiSpeed limits.
Given that 480Mbps bandwidth is used in full-duplex mode, you still get 240Mbps for single data transfer direction overall.
Take away overhead+bus management (33%) and we're still at 160 Mbits per second.
I doubt you'll ever find a video+audio streams that would exceed 160 Mbps.
If a portable USB 2.5" HDD can't deliver ~30 MB/s transfer rate (for large files of course, not many small ones) then it's a lousy product which has no place in my life.

Conclusion: choose a model which fulfills these requirements or get a refund. ;)

Yes, your estimate (and the specs I read) all seem straightforward in that it should be fine @160 Mbps but I still get people (in stores, other forums) quoting only 20Mb/s transfer speed for these USB 2.5" 5400 rpm drives! I'm not sure if they're stating write speeds or read rates. For my purposes, it's the READ rate that I'm most concerned about. Need to be able to read at > 40 Mbps to cover the HD uncompressed titles. The last thing I want is to have playback get jumpy or skip because it can't handle the transfer rate needed.

[mariush]

I think you're making a confusion between MB/s and mbps. 1 MB/s = 8 mbps.

A 160 GB 3.5" 5400 rpm drive will probably start at around 45 MB/s for the first 30 GB, go to around 30 MB/s for the next 60 GB and go lower and lower by the end of the drive, to around 20 MB/s.
The USB interface will probably be able to keep the transfer to around 30 MB/s.

Here's a forum post showing transfer charts for a 250 GB 3.5" 5400 rpm with 8MB cache SATA drive: http://www.notebookforums.com/thread203987.html#12

As you can see it starts at around 60 MB/s and goes down to around 35 MB/s.

All these are way more bandwidth than what a regular movie - even 20 MB/s sustained is 160 mbps and your average blu-ray rip is 12-16mbps and a regular blu-ray iso is probably around 25-40 mbps or 5 MB/s.

[archaeo]

@mariush,

thank you for the clarification. That helps quite a bit.