Comparison of built-in firewire 400 and PCMCIA firewire 800

[rotero]

I have a 1GHz PowerBook G4. I do a lot of work in audio applications like Pro Tools and Live. For many of these audio apps, hard disk activity is heavy, and a high performance drive (or drives in some cases) is essential.

My main production drive is a WD Caviar (IDE, 80GB, 7200RPM, 2MB cache) in an OWC enclosure (Oxford 922 chipset, 1 firewire 400, 2 firewire 800, 1 USB 2.0). I have a Seagate ST340810A (IDE, 40GB, 5400RPM, 2MB cache) in an Ultra enclosure (Prolific 3507 chipset, 2 firewire 400, 1 USB 2.0) as a backup drive. I've been wondering recently if adding a PCMCIA firewire 800 or USB 2.0 adapter to the PowerBook will result in performance improvements. Theoretically, firewire 400 performs at 400Mbps, and firewire 800 and USB 2.0 perform at 800Mbps and 480Mbps, respectively. I don't think USB 2.0 will result in any significant improvement, so I'm mainly wondering whether PCMCIA firewire 800 performs better than built-in firewire 400 and if any improvements will be hindered by the specs of my drives (RPM, seek times, cache size, etc.).

[staypuft]

In reality Firewire 400 is faster than USB 2.0 so don't bother with a USB 2.0 card. As for the Firewire 800 card, it may be a good idea. I found stats covering your question at
http://www.barefeats.com/fire42.html
though I'm still not sure sure Firewire 800 offers significant speed boosts over Firewire 400 when just one drive is attached. Then again you did say you have at least two external drives.

[CAlvarez]

I concur on the USB point--it is well documented that USB is slower than Firewire in the real world.

FW is still faster than the drives. You might see a tiny gain with FW 800 simply by minimizing its impact on the overall performance, but nothing major can change due to the limits of the drives. Also keep in mind that PCMCIA cards have their own limits and issues.

I use dual FW drives on my PB G4 1.67, both on the same channel via a hub. I can see a marked performance hit when both are active, but with a single drive, I can't see any improvement when I move them to FW 800; maybe there is a measurable difference, but there's not a noticeable difference.

I'd love to find a FW800/SATA enclosure. That should be noticeable. But they don't seem to exist yet.

[styrafome]

If you are only running one drive, you may not see much improvement from moving it to a FW800 PC card. However, if you are running multiple devices, you will probably see improvement from running one off the internal and one off a PC card. I ran into this with video editing. I had problems when the camera and the capture drive were daisy-chained off the one FW400 port. When I moved the capture drive to a FW400 port on a PC card, everything ran smoothly, presumably because each device had a channel all to itself.

[voldenuit]

If you're really in the game for insane speed, I'd get the fastest drives you're willing to listen to (at least 7200 rpm/8MB cache Seagates or Samsungs) in FW800 enclosures and run them as a RAID 0 on the FW800 of your PowerBook. Using the second channel with a PC-Card seems to gain little speed according to the benchmark quoted.

Keep in mind that with RAID 0, when one drive dies, your data is gone.

[rotero]

Quote: Originally Posted by staypuft In reality Firewire 400 is faster than USB 2.0 so don't bother with a USB 2.0 card. As for the Firewire 800 card, it may be a good idea. I found stats covering your question at http://www.barefeats.com/fire42.html though I'm still not sure sure Firewire 800 offers significant speed boosts over Firewire 400 when just one drive is attached. Then again you did say you have at least two external drives.

Thanks for the link. Those test results were very helpful. It seems that PCMCIA firewire 800 performed better than it's built-in counterpart in two out of four tests and the same in one. The increased performance of the two-drive RAID 0 arrays was pretty impressive. However, if I were to have a RAID array, I'd want yet another drive to mirror it as a back-up - and I think that's more than I'm ready to spend at this point.

[mkoistinen]

Quote: Originally Posted by rotero Thanks for the link. Those test results were very helpful. It seems that PCMCIA firewire 800 performed better than it's built-in counterpart in two out of four tests and the same in one. The increased performance of the two-drive RAID 0 arrays was pretty impressive. However, if I were to have a RAID array, I'd want yet another drive to mirror it as a back-up - and I think that's more than I'm ready to spend at this point.

To get BOTH performance and resiliance to failure, you'll want to use 4 physical drives and nest two striped pairs into one, logial mirrorer pair (or vice-versa). See this bulletin from Apple:

http://docs.info.apple.com/article.html?artnum=304377

This is exactly what I'm building now, as soon as my other 2 disks arrive! The end result nets you 50% of the total space which is then both up-to twice as fast and up to twice as resiliant (in theory, anyway). Since I'm using 500GB drives as my base, I'll have 1TB of fast, fully redundant space!

[mkoistinen]

Quote: Originally Posted by mkoistinen To get BOTH performance and resiliance to failure, you'll want to use 4 physical drives and nest two striped pairs into one, logial mirrorer pair (or vice-versa). See this bulletin from Apple: http://docs.info.apple.com/article.html?artnum=304377 This is exactly what I'm building now, as soon as my other 2 disks arrive! The end result nets you 50% of the total space which is then both up-to twice as fast and up to twice as resiliant (in theory, anyway). Since I'm using 500GB drives as my base, I'll have 1TB of fast, fully redundant space!

OK, just to report some tests I ran which may help someone. I have a MBP with (only) Firewire 400. Using two of my disks, I set up a RAID Striped set using a partition of about half of each disk. I left the remainder of each disk un-RAID-ed for this test.

Once it was all working, I ran some speed tests. On my system, with the single FW port running at 400MB/s, the results were disappointing. I ran several tests copying 4.4 GB files to and from the striped pair and normal partitions and the results were either equivalent, or the RAID was slightly slower in every case.

I'd bet that if I had a MacPro instead with multiple FW/800 ports, there would be some benefit in speed, but I'm not seeing it with my hardware.

I think I'll try to find a high-performance, multiple-port FW/800 ExpressCard and see if I get the sort of benefits I might expect from RAID striping before I buy more disks.

[trevor]

To get a speed benefit, fill your Expresscard/34 port in your MacBook Pro with a FireWire card. Then you can double your FireWire bandwidth.

FireWire 400 is currently maxed out in bandwidth with a single fast 3.5" hard drive--there's no way that connecting four FW400 drives to a FW400 port is going to give you additional speed.

Trevor