Orphoto Loc: Oregon

My only drive failure was with an early ac powered external. Chances are that on computer boards you can find some truly informed opinions about relative reliability figures. I can tell you that usb 3 connections are quick enough that you are running only a bit slower than a traditional internal spinning platter drive.

SSDs are still expensive enough that spinning platters are more cost effective for extensive photo storage.

You might also consider replacing the current c drive in your configuration with a much larger capacity drive and then just careful copying from old to new, and tossing the old.

TriX Loc: Raleigh, NC

Well, tough to give a useful answer without the information I requested. The way the question is phrased is a bit ambiguous, unless using a Thunderbolt or equivalent port in a Mac, all external drives will be USB (or occasionally eSATA) connected. The only difference is how they are powered - either from the USB port or from a power supply plugged into the AC line. The real question is how large, whether an SSD or a conventional spinning disk, and if the latter, the quality of the drive - cheap consumer or enterprise class. Now if I knew the answers To those questions, I could give a more informed answer.

As far as the way an external conventional HD is powered, there are advantages to each method. iF the USB can supply adequate power, the PC supply is likely to be a better supply than a cheap “wall wart” supply. On the other hand, an AC supply can likely supply more power than the USB limited port and that will allow the enclosure to have a fan which will keep the drive cooler and prolong its life. If an SSD is chosen then it’s a non issue

Wallen Loc: Middle Earth

Each has a pro & con.

A USB external drive, magnetic(portable hard drive) or electronic type (USB drive, SSD, etc.), are prone to fail if the USB connection creates trouble. On the other hand, this set up is much more portable.

Direct mains powered is a little more robust against the same connection issue as it has its own power supply but it will be bulkier.

Those aside, Nothing digital is forever.
A magnetic hard drive can fail. A USB transistor can fail. Even the DVD copies can degrade in time.
The secret to longevity of digital files is back-up. Having multiple complete copies scattered in different locations away from each other in the most recent file format plus hard copies of the most important ones be it text or images.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

My experience has been that portable consumer-grade mechanical drives packaged as "Backup" tend to be lower end drives, hence the low price and attractively large storage. They do not last, have very short warranties, and generally are quite a bit slower than most alternatives. External drives tend to be limited by the speed of the interface, with Thunderbolt 4 being the fastest at around 1100 mb/s transfer speeds. You won' t see this supported on any but the latest Intel 11th Gen CPUs. These USB-powered SSD devices are usually ok getting their power from the USB port on a computer, but if you intend to use it on a USB hub, you'll have to make sure it is AC powered and that it has enough power to handle a drive

The faster and more robust solution for mechanical drives would be drives that are built for heavy duty use, like data centers or enterprise rated drives. You'll know them when you see them because they have 5 year warranties. The are built to last, and the companies that offer them have excellent customer service policies. They cost about double what the consumer grade drives cost.

Getting a fast SSD external drive might sound like a better solution. They don't require as much power to run (they can be used on most powered hubs), have faster read/write speeds than mechanical drives, are not prone do damage from impact, and come in m.2 NVME and 2.5" form factors. However, these are expensive - a 2 TB SSD drive will cost as much as a 3.5" Datacenter/Enterprise drive - around $200 - and won't really be any faster unless it has a Thunderbolt 3 or 4 interface USB-C is pretty fast but not in the same league.

If you are going to use this drive as active working storage, then you'll need to spend more money, and stay away from the cheap, mechanical high capacity drives, unless you plan to buy two of them for redundancy.

ELNikkor

With flash drives now holding 512 gb for $50, I can reasonably back up my best images which are stored on external HDD's.

Don, the 2nd son Loc: Crowded Florida

I have both and favor usb powered external drives because the tangle of "soap on a rope" wires becomes a nightmare at times. Portables are easier to store, in a drawer, closet or safe deposit box. I also favor SSD drives bc they don't have mechanical spinning disks and other moving parts that will fail eventually. SSD's are significantly more $$ though.

Don, the 2nd son Loc: Crowded Florida

I have both and favor usb powered external drives because the tangle of "soap on a rope" wires becomes a nightmare at times. Portables are easier to store, in a drawer, closet or safe deposit box. I also favor SSD drives bc they don't have mechanical spinning disks and other moving parts that will fail eventually. SSD's are significantly more $$ though.

yssirk123 Loc: New Jersey

I have dual 8TB drives on my desktop and Backblaze for cloud backup.

traderjohn Loc: New York City

I agree. There are some who seem in a state of paranoia about backups, how many external drives then these get backed up to another drive and different location.

Real Nikon Lover Loc: Simi Valley, CA

BTW Costco.com has a good deal on external 8TB USB external storage. $50 off @ $119.00 USD each. Max 3 per customer. Im picking up 3.

SuperflyTNT Loc: Manassas VA

That’s what I would do. Clone your C drive to a higher capacity drive and swap.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

They often fail prematurely. I never recommend these consumer grade drives. It's twice the cost, but a robust 8 TB enterprise/data center drive will cost about $240 with an appropriate enclosure. Much better service life and performance.

MrPhotog

The only difference is in how the hard drive gets its power.

If your computer is already powering a lot of devices through other USB ports, then adding more USB-powered devices might cause problems. This is unlikely, but possible, with perhaps a tethered camera or a phone charger plugged into the computer.

While this might be a problem with some older computers, the solution is simple: buy a cheap, powered, USB splitter or hub. Plug your USB drive into this and it is now an AC powered external drive—same as your other option.

On the other hand, If you are completely mobile and away from wall sockets, the USB powered device will work off of the computer’s battery power, while an AC powered device is useless without its wall socket.

If you get the USB device and a powered hub, you cover both bases, and these can serve as phone chargers, too.

coolhanduke Loc: Redondo Beach, CA

If you are investing in a drive, consider an SSD drive. much more reliable and faster.
I just bought a 2 TB Sandisk from Costco. Very pleased with it compared to my Sagate externals, which I've had fail and had to send in for recovery>

mikedent Loc: Florida

Thanks all for the suggestions. Will check out Costco for a usb-ssd drive and compare pricing with more rugged types like Gene spoke of.