Performance of ext. USB 2.0 drives?

One thing that is technically wrong about what you said... your internal lappy drive is 100MB/s... that is megabytes, not megabits... whereas firewire is 400Mb/s, that is megabits. There are 8 megabits in a megabyte, so firewire has a bandwidth of 50MB/s... But, this is max transfer speed, and hard drives don't always use their max transfer speeds, lol. The majority of the time they don't. The speed increase with usin an external drive is that their 7200rpm speed increases access times... It's faster for find files and stuff.

Sooooo...What's the short answer?

Would you notice longer loading times w/ the external or what? Or...dunno. Just tell me how they compare

So what is it, then?

Personally, I'd also like to know what the deal is with these external harddrives is?

First, can they indeed be faster than the native ones, assuming you have a higher RPM (e.g. 7,200).

Second, between externals, which can be described as "faster" overall, the USB2 ones or Firewire ones? What is this access-time vs. throughput argument?

Thanks a lot, and cheers.

K... here's the deal :-)

Hard drives have two main components that are important as far as speed... one is access times and the other is transfer rate. Rotational speed affects access times and the interface (ie: ATA100, or ATA133) affects max transfer rate. This is all general, btw, lol, so take it as such. External hard drives at 7200 rpm are faster with access times because those drives usually have read/write times of like 8 milliseconds whereas 5400rpm drives are around 13ms and 4200rpm are like 19. Considering the number of times the hard drive has to seek, those times really REALLY add up. So, if you have an external 7200rpm drive on firewire or USB2, you get the benefit of faster seek times. This is good for things like searching, changing files, basically doing things that involve seeking :-) Now, modern drives are generally on an ATA100 connectionl, which means they have a max transfer rate (MAX) of 100 megabytes/s. Firewire maxes at 50 megabytes/s and USB2 maxes at 60. Hard drives average at transfer rates of 35MB/s just depending on what is being transfered and where on the drive it is being transfered from. So, USUALLY, firewire is enough and you will only notice an increase in performance compared to the current 5400rpm internal laptop hard drives. Once 7200rpm drives come out, there will be no performance reason to have external drives because performance would theoretically be less (cuz of the bandwidth limitations on firewire and USB2). Hope that helps!

Well, I'll be picking up a fujitsu 20 or 40 GB notebook-sized HDD and a USB 2.0 casing either today or next week, so I should be able to provide up some numbers (assuming if I can find the appropriate benchmarks) with the 5660 soon enough.

The gadgets freak boy -


Rob

You've putting a laptop sized drive in an external case? Why? Lol, you'll only get 5400 rpm in a laptop hard drive? To get the speed benefit of access times, you would need to put a desktop drive in the external enclosure...

Oh yeah, I'm aware about that - and in fact, the drive I'm getting is a 4200 rpm one, not even 5400 rpm.

But that's OK - I'm using this drive in external enclosure totally as a portable HDD to transfer files from my lab and notebook, and also as a secondary backup device too.


Rob

lol, understood... just keep in mind that the performance will be even less than a 4200 rpm drive inside the laptop... so benchmarks aren't going to reflect the standard setup of a desktop drive in the enclosure :-)