Unfortunately, this is not possible.
A little research on your part would've revealed that FW 800/400 drives are available.
Google's your friend.
You can buy hard drives that have FireWire 800/400 connections on them.
Three that come to mind is
OWC (macsales.com) Mercury Pro line of hard drives.
I have found, in my experiences, that most users buy USB drives because they are cheaper.
USB drives do not have a consistent, continuous streaming of data that FireWire drives have.
In real life, this tends to make FireWire drives data throughput faster.
That is why drives with FireWire connections tend to be more expensive.
I might recommend one of the hard drives shown below from OWC, that I also use. They contain USB 3.0 AND Firewire 800 Ports on each unit, in the left hand column of drives.
Radiation Mac--Thank you for the information.
MichelPM--Of course I know that there are external drives with Firewire 800, and I knew that when I bought my external drives (and all without having to do a bit of research). That wasn't my question.
And, yes, I do buy the USB versions because they are cheaper. I'm using these drives for long-term storage of data, so spending considerably more money to get Firewire drives would not make any sense at all. However, if there was an adapter that could allow me to connect all of my USB 3.0-capable drives to my iMac's Firewire 800 port and harness its higher speed (compared to my iMac's USB 2.0 ports), it would be worth spending money on such a device because it would work with every USB 3.0 drive I've bought or will buy.
As to your last few sentences, I'm not sure what you're saying. I have a couple of Seagate Backups+ drives that came USB 3.0 enabled. But Seagate sells an adapter that swaps out the drives' USB 3.0 interface for a Firewire 800 interface. Because these are larger drives I have in continuous use, I bought the Firewire adapters, and they nearly doubled the transfer speed to these drives.
Here's a post from a Seagate forum that points to a gadget (SEAGATE STAE123 GOFLEX DESK V2 DESKTOP ADAPTER) that apparently makes the conversion between Firewire and USB 3 ($40 or so):
This is on Seagate's accessories list for the the Backup Plus Desktop Drive. It looks it swaps with the bottom of the desktop drive to replace the one with USB 3.0 plug with a Firewire plug.
"Upgrade the transfer and access speeds between your Backup Plus or GoFlex desktop drive and your Mac® computer with FireWire® 800 connectivity that’s up to 2x faster than USB 2.0. Features an illuminated LED capacity gauge."
Right now you can get one on Amazon for $33.99 + $5.95 shipping, or you can pay Seagate $49.99 + $9.17 shipping.
Erk, I just lost a long post correcting and adding some information. The one I linked on Amazon is the older version, which does the same thing, and which is also cheaper. The link to Seagate's website is for the new version.
It looks like the package usually comes with firewire and usb cables, but the one on Amazon doesn't have them. I've got tons of cables, so I'm going for the one on Amazon.
I'm a little confused as to the conclusion here. Is there no adapter that will work for a drive that uses USB 3 (or Thunderbolt) to connect to Firewire 800? The drive I have is this one
and I need to connect it to a Mac via firewire 800 if possible.
Thank you in advance!
I realize this is all somewhat off topic, but I had to say something to clarify the statement that "the items listed for the Seagate drive are for that drive only". This is untrue - the variosu GoFlex options are all just direct plug SATA adapters.
The Seagate GoFlex adapters are self-contained SATA to USB, SATA to FireWire or SATA to Thunderbolt bridges. The bare GoFlex drive, of whatever generation, is nothing more than a 2.5" or 3.5" SATA hard drive in an enclosure that exposes the power and data ports on the back of the drive.
The 2.5" GoFlex adapters supply power to a 2.5" drive through FireWire, USB or Thunderbolt directly, while the 3.5" adapter is a larger base which supplies power to a 3.5" drive via a wall wart.
I have regularly used both the 2.5" USB 3.0 and 2.5" FireWire 800 adapters interchangeably with Seagate and bare SATA drives, both rotational and solid-state, and they are perfectly adequate to interface bare 2.5" drives with the arbitrary host system of your choice.
The 3.5" GoFlex bases supply less reliable DC power and Seagate has also shipped a large number of high failure rate and DOA drives in the 3.5" GoFlex kits. I would stay away from those.
I'm still confused. I looked at the image of the Seagate adapter and it looks very specialised. (http://www.seagate.com/external-hard-drives/desktop-hard-drives/backup-plus-desk / )
I have 1TB drives (eg the WD Passport) that are USB3.0 but at the other end of the cable, they only have standard USB2.0 plugs. I'm in the same boat at the OP (JD Lee) in that my iMac has 2 x firewire and 3 x USB2.0 ports.
Is there some way I can make use of the faster USB3.0 transfer rate on the portable drives - or make use of the firewire connectivity on the back of the Mac?