Is FW800 faster than Internal HDD?


macrumors 6502a
Original poster
Jun 1, 2007
I heard that Firewire 800 interface is faster than internal one. Is this really true? And if it is then can I boot OSX from a FW800 drive and use it as my primary drive?


macrumors 6502a
Sep 18, 2006
Prestatyn, Wales, UK
Technically it probably is, but the PCI Interface it runs through will limit the maximum speed.

I'm pretty sure internal drives are always going to be faster.

Old tests using G5 ;

As native firewire drives don't exist, most use a bridge chip to convert from ide/sata to Firewire, which probably explains why the speed is not as great as it should be.


macrumors member
May 22, 2007
well, no, and yes

The interface is slower, but the drive might be faster. It really depends on the drive in your computer. If it is a laptop, an external 7200 rpm drive will probably be faster, but otherwise, no, your internal drive will be faster due to the peak transfer capabilities of the drive interconnect.

Firewire 800 has a peak transfer of 100 MB/s, sata either has 150 MB/s or 300 MB/s, so the firewire interface is slower, but the drive speed is what limits all of these technologies right now.

And, yes, you can boot from the external drive.


Moderator emeritus
Jan 9, 2004
Grand Rapids, MI, USA
Firewire 800 is probably not going to be faster than SATA I or SATA II (1.5 - 3 gbps). It might be faster than PATA.... But I'm pretty sure that at this point, as I've said in many other threads, single hard drives are not capable of matching the interface speed anyway, so you will not see substantial improvements. For instance, when you take a hard drive in a FW400/800 enclosure and test 400 vs. 800 (where you should theoretically get close to a doubling of speed), you only get a 20% increase in speed. Why? Because the hard drive cannot sustain cache-to-interface transfers at 800mbps anyways.

EDIT: To sndcj1's point, I am talking about using the same hard drive. His/her point is certainly valid, that if you pair changing to Firewire with getting a faster drive, the result may be different....


macrumors 6502a
Original poster
Jun 1, 2007
Ok so simply put, if I have a laptop 5400rpm drive, then the FW800/400 7200rpm would be faster for me. Secondly it is better to save your money rather than buy a FW800 drive, right?


macrumors newbie
Nov 21, 2006
Yes, with a fast external HD you'll get better performance that with your laptop internal 5400rpm HD. If possible I would also go for a 800-compatible one if you are all into performance. Like was said on a post above, the speed increase 400 vs 800 is something like 20%. Haven't messured this myself, but thinking that could be pretty accurate from what I have experienced myself.