True limit to PMR

**AndreL** · October 12th, 2012, 03:05 PM

Is the true limit to PMR 1Tb/inch^2 cause I read that we are currently at
625Gb/inch^2 and the bigs single drive I've seen is 4TB at about $250

And with the new HAMR how big a drive are we talking here, will it go in to the Peta bytes

**ShyguyXPC** · October 12th, 2012, 03:11 PM

If we're only at 4TB right now, we have a LOOOONG way to go before we hit Petabyte range. (1000 or so Terabyte would be a Petabyte, we're currently at less than 1% of that, 0.004% of a Petabyte and considering HDD's are still the slowest part of a PC, and the lowest evolving parts in a PC, not likely to see drives in that range for decades if even then.)

**Taxmancometh** · October 12th, 2012, 11:02 PM

What does PMR mean? I tried Wikipedia and found nothing.

**ShyguyXPC** · October 13th, 2012, 12:11 AM

Seagates tech they came out with a couple years ago

Perpendicular recording - Wikipedia, the free encyclopedia

Perpindicular recording.

Allows more denser data stored per platter than before, reason why some of the thin drives out there, like the one 1TB Seagate I keep using in peoples builds, is a single Platter drive.

More info on HAMR: Heat-assisted magnetic recording - Wikipedia, the free encyclopedia

**Taxmancometh** · October 13th, 2012, 01:39 AM

Does magnetic recording still have a future? I was under the impression that SSD was where it was at in today's tech.

**ShyguyXPC** · October 13th, 2012, 01:45 AM

actually HAMR does still have a future, there's been several storage mediums, or techniques anyways, in the news over the past couple years, that should significantly boost existing drive storage technology.

But as for SSD's, yes, when it comes to SPEED, but for just raw storage and data back up, SSD's aren't the best thing necessarily, at least when it comes to price per GB of storage currently. plus most still have a relatively limited lifespan compared to standard mechanical drives, the irony in the whole thing, non moving parts, shorter lifespan, moving parts, greater lifespan.

**Taxmancometh** · October 13th, 2012, 01:56 AM

That's crazy. Non moving parts, shorter lifespan, moving parts, greater lifespan. I always thought the mechanical wear (Or MTBF) was a big factor for hard drives. I have a 120 GB Adata SSD, I just hope what I have been reading about SSDs is true in that when they bite the dust it just turns into a read only device. I have over 20 GB of Flight Simulator data on that SSD.

**ShyguyXPC** · October 13th, 2012, 02:39 AM

SSD's are evolving and hopefully much more longer lasting, but I think it is the Writes to it that kills it, much the same way as Flash Cards and USB Drives die due to too many writes.

down side to mechanical drives is many more parts could go bad and condemn the drive, plus read and write ability is affected, so each has its pro's and con's.

**paul9** · October 13th, 2012, 05:58 AM

Yes, the flash memory used in SSDs has a limited amount of writes before failure. On the upside, it is a failure to re-write, not a failure to read, so you don't lose your data, it just becomes read-only after a while. Not ideal for a drive.

The classic flash presentation on PMR storage. https://www1.hgst.com/hdd/research/r...Animation.html

**AndreL** · October 24th, 2012, 05:52 PM

Great video Paul9 do you have one for how HAMR works

But the post has gone away from the question PMR I've read in some articles that it will going up to 16TB (Is that ture) don't know if it is, but I have seen HAMR will top out at 60TB. And it has something to do with lasers which makes me wonder about the surface and that brings into question the life time span of a HAMR drive

**paul9** · October 24th, 2012, 07:07 PM

Well it is probably to do with the physical size of the platters they can put in the standard drive casing. If they wanted to make a bigger sized casing as a new standard, you could get more platters, and a larger diameter. That would increase the limits a lot.