Mac laptops forum: Speed of a 2TB 7200 drive on FW800 vs. RAID5400 on TB

It was a question, but I'm sure you knew that..

I can't do testing myself for a few reasons :

1.) MacBook Pro is dead (http://forums.cnet.com/7723-21565_102-561465/reviving-a-dead-early-2008-macbook-pro/)

2.) MacBook Air has no FireWire ports, and any adapters are extremely scarce and expensive

3.) I don't own the LaCie Thunderbolt drive (yet), and I am not going to purchase it, unless I can make sure that the performance will be at least the same or better. (That Thunderbolt drive is not cheap.. and I would need at least two)

Which is why I asked my question about these.

So, I was hoping that experts here can contribute something helpful. At least in theory, people here are better informed than me about how these things work I believe... While I know that Thunderbolt drives are not widespread as of yet, somebody might be familiar with the connection types and drive speeds.

Anyway, working with 2TB of media files on a daily basis connected by USB is a painful experience. So again, any suggestions would be highly appreciated!

Tells me that only benchmarking will give us the answers. And this is costly. However there is some known limitations worth knowing about that I use to foretell which setup is faster.

We know that almost all spinning rust (hard drives) have a media write speed limitation. You can read that online and I will not be vetting my answers in this discussion.

The number is from 100 to 200 megabytes per second which means that SATA 1.5 was about as fast as it goes. There are minimal gains as the interface speed goes up but folk always hope.

This is why RAID 0 can write so fast.

Hope this helps.
Bob

I am guessing then the two 5400rpm drives in RAID 0 should be equal or better than the single 7200rpm drive, and the connection type is not the bottleneck here (FW800 vs. Thunderbolt)

What does not make sense still, is that - at least in theory - both USB 2 and of course FW800 greatly exceeds the spinning hard drive's speed limitation, there is a huge difference when currently using USB vs. Firewire previously. Does this have to do with sustained transfer rates, which might be that much better for FW?

For years I was getting data recovery jobs from folk trying that on Windows. It's a known issue and one where I never write nice if this is going to be on Windows.

The discussion about sustained writes is done. I don't think we need to repeat that.

RAID 0 should win. And no need to go 5400 at today's prices.
Bob

You're close... USB was intended to be a cheap alternative to the likes of FireWire, and as such they cut quite a few corners. One of the corners cut involves using the main CPU, not a dedicated control chip, to do most of the heavy lifting on USB. So FW works more or less the same no matter how bogged down the CPU(s) are, while USB will suffer.

And of course theory and reality never quite meet with computers. There is latency involved with converting the signal from the HDD to FW/USB, and then back again, fragmentation on a drive can result in the head having to move more often to find a bit of room instead of laying the data down in one nice smooth continuous track... A lot of people don't catch on to the fact that FW and USB are measured in MegaBITS per second, while HDDs are in MegaBYTES per second, which gives them rather inflated expectations.

In the end, I think you're spending way too much time and effort on a fairly trivial subject, but I suppose a person could waste their time in far worse ways.

Basically I just need to find a fast media drive solution for use with my MacBook Air. I only have the choice of Thunderbolt or USB on the MB Air. Thunderbolt drives are rare and expensive, and the only one I found being relatively portable is the LaCie Little Big Disk Thunderbolt (with two 1TB 5400rpm laptop drives in RAID 0).
The best price I found for these is about $500 on sale ($600 list), and I need two of them..

So I was just worried to spend a lot of money on something that might not work well.. But I stop worrying I guess, as it seems this set up would be a bit faster in theory at least, than the previously used single 2TB 7200rpm desktop drives connected by FW800.

http://www.amazon.com/Seagate-GoFlex-Thunderbolt-Adapter-STAE121/dp/B006P1QWOQ

It looks like there may be an issue there.
Bob

Yes, read all reviews on anything Thunderbolt-related on Amazon, also seen the Seagate adapter you linked to. I was hoping, that the LaCie would be using a different controller being a different brand, but who knows.

The drive I am looking at is this one:
http://www.amazon.com/9000107-DAS-Hard-Drive-Array/dp/B0068DOSUQ/

Do I have any other options?

If you were using a MacBook Air, could not deal with USB for external drives for media work on the go, and only had Thunderbolt available on the Air other than USB, what would you choose?

Start with http://www.amazon.com/Cavalry-eSATA-External-Enclosure-EN-CADA2B-ZB01/dp/B004KKXLLG/ref=cnet

And I really like the Momentas Hybrid drive. It was so good that I ordered a second to replace a good working drive in my other laptop.

If I was to do this, I'd get that case then a pair of these:
http://www.amazon.com/Seagate-Momentus-7200RPM-Hybrid-ST750LX003/dp/B00691WMJG/ref=cnet

It's not 2TB but 1.5 and my bet is with the 2.5 inch drives in such a big enclosure it will be cool and quiet. Yes, I might have to get some mounting kit or make my own but I do that sort of stuff (I make things.)
Bob