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This is three questions in one, but: I'm thinking about getting a Macbook Pro with an internal SSD, and the prices are prohibitive for anything aside from the 128GB SSD. So the questions are (links to other Superuser questions welcome!):

  1. Is SSD really that much faster than 7200RPM? I've seen some Youtube videos that make it look 4-10x as fast with OSX
  2. Is Firewire 800 really faster than USB 2.0 for a 7200RPM hard drive? I have seen some questions on Superuser arguing that, but they've had no hard data (just anecdotal "in my experience" stuff)
  3. Can Firewire 800 drives be powered by bus-power only? Or do they need a power source as well (that would be a serious buzz-kill).

Note: Regarding #3,the Macbook Pro has only the little firewire connector (Firewire 800, I think).

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1, Depends on the SSD. The main advantage is in seek time, so reading lots of small files (like booting an OS or compiling) is faster, streaming a full drive of eg. video probably less so.
You also need to check the specs of the individual drive - not all SSD are created equal.

2, Firewire 800 and USB2.0 are both faster than the sustained read speed of a typical harddrive. Driver support may also limit you.

3, Allegedly - although perhaps not 1TB 7200 rpm dirvrs - check the specs

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FWIW, USB 2.0 (480Mbps) ~= 60 MB/sec. On a single 1TB drive I can get 105MB/sec read using eSATA quite easily. – Chealion Jul 5 '10 at 6:41
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Basically, go with Firewire for the Macbook.

Firewire 400 tends to provide better throughput than USB 2.0 even though it's theoretically slower because it's harder for devices to fully saturate USB. There are a variety of reasons for the difference based on where processing happens, etc. I'd expect Firewire 800 to far outperform USB 2.0, though I'm less sure about USB 3.0 which I believe should be showing up this year.

Another option that you don't mention (probably because it's not supported on the MacBook Pro) is eSATA, with performance exceeding either Firewire or USB. In terms of raw performance for drives from best to worst is: USB 3.0 (when available), eSATA I, FireWire 800, Firewire 400, USB 2.0. Eventually eSATA II and FireWire 1600/3200 will also be available and will come in at the start of that list.

In terms of power, Firewire with an Alpha connector (the large 6-pin one) can provide the most and shoud power an external laptop hard drive. eSATAP should do the same but isn't relevant here. USB 2.0 external laptop drives that I've used that don't use an external power supply all use a custom USB cable to draw power from 2 ports - technically each port should only be providing up to 500 milliwatts, which would be right at the very edge for many laptop hard drives.

While the Wikipedia pages for USB and Firewire are useful, perhaps most informative is the Serial ATA page. The section on eSATA and e-SATAP is informative, and the comparison to other buses is useful even for comparing USB and Firewire: http://en.wikipedia.org/wiki/Esata#SATA_in_comparison_to_other_buses

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the macbook pro, I think, only has the little firewire connector. Does that mean it cannot power an external drive? – Yar Jul 4 '10 at 5:53
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@Yar: FW800 uses the 9 pin connector which does provide power just like the physically larger 6 pin connector used by FireWire 400. The unpowered connector you may be thinking of is the 4 pin version (Sony called it i.Link). Additionally Firewire 800 has a theoretical maximum of 800 Mbps versus USB 2.0's 480 Mbps. – Chealion Jul 4 '10 at 14:32
Thanks @Chealion. I'm not sure what I'm thinking of. I have a proto-professional audio interface (Edirol) and it can only be bus powered through the bigger, USBish-ended cable. So you're saying that all is well with this arrangement. While we're here, how slow would it be to put the SSD in the firewire enclosure for reads? I really don't need it for the system drive but rather for some software that reads about 20GB of .wav files continuously. – Yar Jul 4 '10 at 17:19
@Yar: Depending on the enclosure you would have all the advantages of extremely low seeks times on an SSD but theoretical throughput would be maxed out at 100 MB/sec (800Mbps) - so unless your .wav files exceed a bitrate of even a quarter of that I wouldn't be concerned. A 7200RPM drive will run slower than that, especially one that is bus powered. – Chealion Jul 5 '10 at 6:40
Thanks @Chealion. You've convinced me to look at the WAV bitrates and so forth. I'm sure that will result in another question here. The interesting thing that I didn't know is that the Macbook Pro 17" allows for eSata, which could be interesting: buy it with the SSD, take it out and throw it in an eSata enclosure, and put in an internal 500GB 7200rpm HD. – Yar Jul 5 '10 at 14:26
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