Lookin' for a new external that will satisfy

November 4, 2007 2:22 PM

Leopard / Time Machine / External Drive Filter: Looking for a new 2.5" external. How big should it be if my internal is 120 gigs? Firewire or USB?

My initial thinking is that USB is more common, I can plug it into PC's if I care to make an NTFS partition, and I've seen drives that allow you to daisy chain other USB things through the drive. But being relatively new to Macs, are there things Macs can do with Firewire(400?) that they can't do with USB?

posted by dino terror to computers & internet (22 comments total)

It depends on how often you modify files - if you never touch anything, you don't need much more than the space you actually take up. I'd think 250gb would be more than enough; 160 might be fine in practice, but you'll most likely not be able to go very far back in time.

On paper, USB2 (480mbps) is faster than Firewire (400mpbs). In practice, for hard drives, you'll see better performance out of Firewire. But a 2.5" external's probably going to be USB2 rather than firewire - I haven't actually seen any FW drives that small. Also, pretty much all FireWire drives these days are both FW and USB2, so you can get the better speed on your Mac without sacrificing the ability to plug it into a PC. On the other hand, as you noted, that'll require making a non-HFS+ partition.

Also, if you want easy portability between Mac and Windows, you'll want to make that partition FAT32 rather than NTFS; NTFS has not-so-great usually-read-only support from non-Windows operating systems, while FAT32, for all its failings, is definitely the lingua franca of the filesystem world - Macs, Windows machines, and Linux can all deal with it effortlessly.
posted by Tomorrowful at 2:45 PM on November 4, 2007

The Time Machine drive must be formatted HFS+ (Mac's native file system), so it can't be shared with a PC.
posted by mpls2 at 2:51 PM on November 4, 2007

Mac's can boot from Firewire drives, so if you use carbon copy cloner or superduper, you can make a mirror image of your hd and then reboot holding down the option key and choose to boot from the firewire.

I don't have leopard or timemachine but drives are pretty cheap, so you should get ~200G. I think timemachine lets you use the extra space on the drive.

I'm planning to get another drive, and was looking these.

They have both firewire / usb ports. OWC also sells just the enclosures if you want to try to save some money by buying the drive somewhere else.
posted by JulianDay at 2:52 PM on November 4, 2007

Time machine only works on HFS+ formatted partitions unfortunately.

I also haven't seen a FireWire 2.5" enclosure - perhaps it has to do with the power required to run the drive that only USB provides?

I think the biggest size 2.5" drive you're likely to find within the realm of affordability is ~250gb.

So, if you split that in half for a 125gb partition for Time Machine and a 125gb FAT formatted for sharing between OS's I don't think that it is an optimal set up, especially for Time Machine...
posted by puddpunk at 2:56 PM on November 4, 2007

Mac's can boot from Firewire drives

This implies that a mac can't boot from a USB drive, but that is not the case. The one caveat when booting a mac from a USB drive is that if you have an Intel-based mac, you need to format your drive with a GUID partition table. PPC-based macs can only boot from USB drives with Apple partition tables.
posted by rajbot at 3:18 PM on November 4, 2007

2.5" Firewire bus-powered drives: http://eshop.macsales.com/shop/firewire/on-the-go

Pretty reputable seller. Firewire is a much more efficient protocol than USB, IIRC, so better for speed (and you'll want every little bit, if early Time Machine reports are to be believed.)

To boot off the drive and reinstall the OS in the case of a disaster, you can use your Leopard DVD and Disk Utility to:

(1) create an image (.dmg file)
(2) restore that image to your external Firewire drive (approximately 6.6 GB)
(3) use the remaining space as your Time Machine target.

Then, if your primary drive takes a dirt nap you can boot from the Firewire drive, install Leopard on your new drive, and restore from the Time Machine files on same drive. Yes?

Note - I haven't yet tested the "restore Time Machine data to fresh OS install yet" part, so take that idea with a grain of salt.
posted by ZakDaddy at 3:22 PM on November 4, 2007

I'm looking at getting a firewire interface purely because my iMac only has three usb ports, and two are always in use by my keyboard and iPod cable.
posted by cwhitfcd at 3:40 PM on November 4, 2007

cwhitfcd: You're aware that you can pick up a USB hub for >$25, right?
posted by Tomorrowful at 4:04 PM on November 4, 2007

Tomorrowful used the wrong arithmetic symbol :)

Actually, you can get one at [evil] Wal-Mart for $15-20. Depends if you want a powered one or not. USB hubs are cool. Get a few.
posted by DMan at 4:07 PM on November 4, 2007

any Apple Store will carry some FW/USB (and just FW) 2.5" external hard drives - things from SmartDisk/Verbatim, LaCie and Iomega. (there's a lot of PPC macs out there, and none of them will boot off a USB disk.) if you get the next size or two up, you can keep an image of your computer on it (use Carbon Copy Cloner or something similar) - if your drive dies, you can boot up off of it until you get it replaced or you can (probably) take it to another computer if you've got a spare. (I've taken an install of Leopard from a new Mac mini and booted a first-gen MacBook Pro successfully on it - that won't work if your other machine's PowerPC, though.)
posted by mrg at 4:07 PM on November 4, 2007

Tomorrowful: I like to avoid extra desk clutter wherever I can...
posted by cwhitfcd at 4:07 PM on November 4, 2007

As others have said: Firewire 400 is faster in practice than USB2, and your backup drive must be formatted as HFS+ to work with Time Machine. Size-wise, Time Machine will use as much space as you give it -- that is, the size of the drive determines the depth of its memory. Give it a terabyte, it'll use it eventually. So, the drive should be at least the size of the one it's backing up. Of course, you're not using all 120 GB of your primary drive, are you? I'd say figure out how big your collection of important bits is likely to become and double it. Note that you can specify folders / drives for Time Machine to ignore, too, so if you've got all of your MP3s or video burned to backup discs, and aren't worried about their potential lifespan, you can exclude them and save some drive space.

Time Machine will back up files from another partition on the same drive as the backup space -- it's not really a best practice, obviously, since physical failure would take out both copies of your data -- so if you wanted to buy a 500 gig external drive and partition off some space to use for something else, you could, and Time Machine would back it up if you wanted it to.
posted by mumkin at 4:10 PM on November 4, 2007

I absolutely LOVE my Wiebetech Toughtech Mini 2.5" enclosure. I bought it to hold the 100GB harddrive I pulled out of my Macbook Pro when I upgraded it to a 160GB drive.

This enclosure can be bus-powered over either Firewire400, Firewire800 *or* a USB2 connection, and is utterly rock solid. It also has an external power adapter, in case your bus source cant adequately power the drive. I've been carrying my Toughtech Mini in my backpack every day for the past year, and as of last week, I've am using it for my Time Machine backups. Of course, since the drive I put in it is only 100GB, I have to tell Time Machine to only backup selected folders, but you can stuff a larger capacity drive into it with no problem.

Wiebetech makes among the best enclosures on the market, so you can be assured of thier quality and reliability.
posted by melorama at 4:45 PM on November 4, 2007 [1 favorite]

like melorama just said, the tough tech mini is a SOLID enclosure. i did the same thing when i upgraded my laptop hd... I ended up getting the one that had 2 firewire800 connections and 1 eSATA connection since we use eSATA at work a lot.

great quality, super easy to assemble and it looks pretty too!

my vote goes with Wiebetech.
posted by hummercash at 6:04 PM on November 4, 2007

Interesting info, thanks!
posted by dino terror at 7:50 PM on November 4, 2007

To clarify / disagree / chime in on a few specifics:

- Any Mac made in the last six or seven years will boot off a FireWire drive, but only Intel-based Macs will boot off USB. (Unless you want to hack around in open firmware - not recommended.)

- If you want a bus-powered 2.5" drive, you can definitely get USB-only, FireWire 400 only, USB/FW400, or USB/FW400/FW800. FireWire (400 or 800) has more power on the bus, and hence should only need to take up 1 port to power the drive. Bus-powered USB drives are going to take up 2 of your computer's USB ports, or they'll need a separate power supply. The Weibtech TouchTech Mini linked above is not an exception. (Scroll down to "AC Adapter" for details.)

- Lots of good HD recommendations already. Personally I've had luck with LaCie Mobile drives, but I haven't tried most of the other brands linked here.

- I've never seen a hard drive that lets you daisy-chain USB, but this is extremely common with FireWire.

- Time Machine saves the hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for everything older than a month. Hence, Time Machine will pretty much take as much space as you give it. When you fill your Time Machine drive to capacity, it deletes the oldest weeklies to make room for the newest hourlies.

- So, considering that, remember also that bigger drives are generally more cost-effective than smaller ones. I'd get a 160gb or 250gb.

Good question!
posted by churl at 2:15 AM on November 5, 2007

PS: if you're interested, there's a great and extremely thorough breakdown of Time Machine on this page of John Siracusa's Leopard review. It gets into the real nitty gritty about halfway down the page.
posted by churl at 2:20 AM on November 5, 2007

I've just bought a Western Digital MyBook, and it's working fine. As it comes pre-formatted as HFS, it'll work immediately on plugging in.
posted by seanyboy at 6:39 AM on November 5, 2007

For anyone still reading this thread, should I be trying to get SATA II, and what determines whether I will be able to power the drive from the bus? Ive got a MacBook Pro C2D. Does it depend on the enclosure, the drive, the computer?
posted by dino terror at 10:44 AM on November 5, 2007

Bus-powered USB drives are going to take up 2 of your computer's USB ports, or they'll need a separate power supply. The Weibtech TouchTech Mini linked above is not an exception. (Scroll down to "AC Adapter" for details.)

This is simply not true. I plug my ToughTech Mini into my MacbookPro almost every day through a single USB2 connection, and it powers up with no problems. In fact, I have no idea where my original power adapter is, since I've never, ever had to use it.
posted by melorama at 11:11 AM on November 5, 2007

You can use MacDrive to connect to a Mac-formatted drive from a PC. Not the cheapest software out there, but it works beautifully.
posted by streetdreams at 2:58 PM on November 5, 2007

Thanks for the followup melorama -- I apologize for my mistake. I was misled by the Weibtech site, where they say "You will need an AC adapter if the port you use does not provide enough power for ToughTech mini. This includes all 4 pin FireWire hosts [...] and USB ports." I expect they meant to say USB 1 ports, which provide less power than USB 2. Good to know!
posted by churl at 4:54 PM on November 5, 2007