I've got a nothing special 1Tb Western Digital hooked up to my iMac (2.6 ghz dual-core) and I've been using it to edit miniDV with no problems.
Maybe some time I should give it a real workout and see if it handle AVCHD!
Meantime, I don't mean to make any universal statements about USB-connected drives. All I can say is that in my experience, mine works just fine.
Does that muddy the waters enough for you?
The problems that I personally encountered were:
Slow data transfer times
Read/write errors, and even the dreaded "Delayed Write Error," which could corrupt the entire drive. Others encountered these too.
Now, my experience was when USB externals were just coming out, and before FW-400's were readily available. Maybe controllers and buffers have gotten better? The USB units worked fine for archiving, as the transfers were fine, from Explorer, etc., but when trying to edit to/from, the programs and the OS's of the day, often exceeded the transfer capabilities.
Have not tested those in years, and just relegate them to archiving.
You might want to also ask Jim Simon (PrPro Forum), for his take. He uses USB externals, and has stated that he's never had an issue. He has even refuted my observations, based on his. However, his good fortune does not negate the 100's of error issues on the old Maxtor forums, plus many others too.
My concern is in over-selling people on the hardware needs of this program.
True, it does require a top-notch processor (dual-core for standard definition and quad core for hi-def), good RAM load and ideally a second hard drive. But we often recommend specs to people on this forum that, if someone had recommended to me, would have scared me away from video editing for good!
Premiere Elements is consumer software. It shouldn't require three eSata hard drives, massive graphics cards and hot-rigged operating systems. It should work with camcorders and computers that are virtually right off the shelf. And, in my experience, it usually does.
So I tend to aim lower than you guys. I mean, if it truly requires $2000 worth of hardware to run this little $75 program, then something is very wrong.
Not that you can ever have too much hardware either....
Thanks to both... I've updated my notes file
Hunt may be correct that "early" motherboards with USB don't do as good a job as "recent" motherboards... plus not all external enclosures are created equal
Over in a completely different forum (DirecTV) there is discussion of using eSata to expand the recording capability of a DVR... with mention made of a brand (or two? - not there, can't remember names) of eSata enclosures (or maybe it is individual hard drives... again, not there and can't remember details) that simply do not work with a DirecTV DVR... the point being that not all hardware is equal, be it computer or DVR related
Anyway... when someone mentions using an external drive... I will point them here instead of just saying that USB isn't fast enough
My experiences with USB externals actually goes back to before PrE, with Pinnacle Studio 6 and then AVID Liquid. This was also back with few companies offered externals, and a Maxtor 250GB was considered giant.
When FW-400 externals were introduced, I tested with them, and found that the read/write errors disappeared. Still, the speed was just too slow for me, but that is a personal decision, and so long as the process was not prone to failure, worked fine. With the release of FW-800's, I had the best of both worlds - stability/security and also adequate speed. I invested very heavily in those, and have had only one issue, but with one particular drive only. Now that eSATA is common, I will head in that direction, but will still need the backward compatibility to my FW-800 drives, so will have both.
Like Jim Simon, that you are not having any issues with USB externals, could well mean that they are much better now. I just recall the horror (and the horror stories from many others) of read/write errors, and how that affected my decisions to use, or not use the older USB's. When one has a major Project on an external, and due to a Delayed Write Failure error, then the realization that the drive was then totally corrupt is still fresh in my "closet of nightmares." Even if the errors are but a footnote in history, the speed is an issue that I cannot live with.
I encountered issues with both MoBo USB connections, and also with higher-end PCMCIA adapters. Neither worked well enough for me to trust USB's, when editing to/from. Maybe things are much better now, but the "trust" is gone for me.