Storage Are SMR hard drives that bad?

For my Windows 10 system, I’m speccing a 2TB spinning HDD as a File History backup drive to it’s 2TB SSD data disk but most drives from the usual suspects seem to use the often maligned SMR technology rather than CMR, the result being slower write performance. But are SMR drives that bad? The Seagate and WD Blue 2TB drives I’m looking at both have 256MB cache which I’d guess goes a long way to mitigating the slower write performance.

Are SMR drives to be avoided? (difficult seeing as so many HDDs are SMR)

 

I'd probably avoid but if you just want to whack a load of data on there to backup I'd probably be ok with it.

I wouldn't choose it for anything with alot of read/write though.

 

As a File History drive it’ll be written to every time a file on the SSD data drive changes so it looks like I’m better off seeking a CMR drive, but considering most new drives these days are SMR and equivalent CMR drives are scarce (or double their original RRP due to dwindling stock and high demand), it’d make more sense to re-purpose the 2TB backup drive from my old system and replace it with an SMR drive.

 

In that case I’m staggered that the latest WD Reds are SMR. I was very fortunate to find that out soon enough to be able to add another two 4TB CMR WD Reds to fill up my QNAP NAS before the availability and price of the CMR drives became a problem.

 

It think over certain capacities WD are CMR and also on their website shop it will tell you what variant (like the 4TB Blue, the 64mb cache 5400rpm is CMR and is stated in the specs, the 256mb is SMR (but SMR not stated oddly) both the same price as well)

Which is an improvement over just doing it on the sly.

Seagate have a list https://www.seagate.com/gb/en/internal-hard-drives/cmr-smr-list/ but I think WD it's more of a looking through to find out, not sure if they have an equivalent easy read list.

 

Thanks, so I guess a large cache is an indicator of SMR to mitigate the slow writes, though for large file writes it doesn't really work by all accounts.

 

What's the actual problem with SMR and when did it become a thing? Is it just slower write speed?

I ask because, looking at that Seagate list, it appears I have bought exclusively into the SMR club (unless age matters, as mine are all several years old, although hardly used).

EDIT: Realised I was being lazy and just found this - Choosing Between CMR and SMR Technology in Hard Drives (securedatarecovery.com)

 

SMR is a fairly recent development so your disks probably use CMR technology.

 

It seems that if you require a relatively small capacity CMR disk, then you may have to pay more than twice the price of the SMR equivalent. For example, OCUK stock both the Seagate Barracuda 2TB and it's Pro version, which are SMR and CMR respectively, but the latter costs £114 compared with £45 for the former.
I can buy an Ironwolf NAS disk for around £66 but using NAS-aimed disks aren't designed for the large numbers of power-on/off cycles of a desktop PC and their firmware is supposed to work with a NAS device's controller (which a PC won't have) otherwise read errors and bad sectors increase over the life of the NAS disk, so that's not a good option either.
I've seen a used WD Blue 2TB that's CMR being offered for sale at over £100 on Amazon, I guess that's market forces for you.

 

That's ridiculous, on the WD store it's 81.99 for a 4TB Blue CMR drive . That's new and twice the capacity.

If you've not bought direct before and sign up for the newsletter you get 10% off too (15 for for students under another offer iirc, lucky blighters)

Edit: I have no idea of that used price, on the WD store the Blue 2TB CMR version is 47.99 new.

 

Thanks for the heads up about the WD store @adidan

 

No problems mate, they often have random offers on there too. I've bought direct from them, iirc it was pretty quick.

Like I say though you have to check individual drive specs - they show when they're CMR - sometimes they say if they're SMR and sometimes it's blank (from what I can see they're usually SMR too)

 

As an aside to this thread, I have a 4TB WD Elements external back-up drive. I can write many GBs of large video files to it without slowdown, am I right to think it must be a CMR drive?

 

My understanding is SMR disks basically have a block size (256MiB) and you can append data to that block until it's full, but then if you want to go back and change even 1 bit, the entire block has to be read into memory and re-written. Not good for an OS disk, but fine for media storage or other large files that are infrequently written and then deleted in their entirety when you're finished with them.

I personally have a Seagate 8TB archive drive in my server that I've been using for media streaming and other long term file storage. Been running solid for ~6 years now (knock on wood).

 

I know one example isn't any kind of proof, but I have had 16 5TB 2.5" SMR drives in 2 8 disk ZFS RAIDZ2 arrays for 3+ years.

The only issue I've had is slower rebuilds (7 days to replace a drive). Other than that they've behaved exactly as any other drive with fast reads and writes even for large files.

I probably replace one drive every 6-9 months, which is an acceptable failure rate for a large array.

 

Don't forget topcashback if available - can send you link for mutual reward if required...

 

I've just re-read this - that's a LOT of storage! Have you got one of those underwater CIA data centres?

 

I had a quick look into prices (on Scan) yesterday, just out of interest and found this:

18TB Exos £310 = £17/TB (enterprise)
12TB Barracuda Pro £334 = £28/TB (pro desktop)

18TB WD Purple £558 = £31/TB (surveillance)
18TB WD Gold £578 = £32/TB (enterprise)
12TB WD Red Plus £310 = £26/TB (NAS)

So I started wondering - what causes the disparity in pricing there (in terms of features, applicability etc.), how come the NAS drive is cheaper than the Barracuda but more expensive than the Exos enterprise and can we just shove enterprise drives in our desktops to take advantage of both CMR and apparently cheaper per TB costs?

The other thing I noticed is that drives these days are almost exclusively using 7200rpm speeds, don't remember seeing any 10,000rpm ones - have we moved away from all that now? And has anyone used/can report on the Ultrastar or Toshiba drives? These seem to hit a decent price point but I have no idea how reliable they are.