Storage Solutions SMR Drives and read write speed hell


6pack

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Don't know if people here know about SMR hard drives. These are supposedly new tech that double the data density on hdd platter. With a huge drawback. Write speeds are very low. Like less than 1MBps.
In my case it falls down to <500KBps after the buffer on the drive fills up and it starts lagging in writing to the disk. Most of the 4TB+ hdd's sold on Amazon india by both Seagate and WD are such crap drives. And looks like all hdd manufacturers are doing this.

wIn my case it was problem with 4TB WD portable hdd. One of those yellow coloured ones. I was seeing problem with qbittorrent stop downloading data to that drive after some time. All the random writes would fill the buffer and make the torrent program think there was some problem with I/O and it would go into paused status.

Even copying to another hdd would be dead slow read speeds with these drives. Completely useless stuff. Drives look like they died but they are not. And most of them don't come with the SMART installed on them so people cannot make out if the drive is bad etc.

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If you are getting very low speeds problem is with the drive now. Not your system.

https://arstechnica.com/gadgets/202...re-being-submarined-into-unexpected-channels/

This has become a big debate on Reddit in past few weeks.

smr-crap.png
 

Marcus Fenix

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I was seeing those articles on Anandtech and guru3d but thankfully none of my drives have that issue.

I gues you're talking about the WD Elements drives. I had some longevity issues with those and from then on I have used WD Ultra exclusively for portable storage.

Recently I got a 10 TB WD external HDD from a TE sale but have had no issues with large data backups running into 100 GB sometimes using Beyond Compare with that as well.
 

SunnyBoi

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Recently I got a 10 TB WD external HDD from a TE sale but have had no issues with large data backups running into 100 GB sometimes using Beyond Compare with that as well.
Old white label WD drives are proper CMR Reds. I have one shucced and used in my PC now.

As per WD, there are no SMR drives above 6TB so we are safe anyway
 
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booo

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SMR drives are supposed to be used for cold storage. like Amazon S3 Glacier, they are not supposed to be used for high throughput. Basically they write in between tracks and use helium filled drive enclosure etc... Thats how they achieve high density. They require some tuning in file system drivers too... So, the slow speeds could be many reasons.

SNIA had some really good tech talks on SMR drives. https://www.snia.org/sites/default/...lo_SMR_Next_Generation_Storage_Technology.pdf is one of the presentation. Not sure if they had any videos uploaded.
 
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vyral_143

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So 2TB drive I got last year July is SMR drive - WD20EFAX. My steam downloads max out at ~40MBps of disk usage rate.

I am planning to downsize my case and 3.5" hdd is indeed tough to fit in those small cases like SGPC K55. Now this news kinda supports my urge to get 2.5" internal drive and get rid of current 3.5" drive.

EDIT: Funnily 1 and 2TB 2.5" drives from WD are SMR as well.
 
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6pack

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I think all the new drives are SMR. I've read that the manufacturer can add roughly 20% additional capacity per platter with this tech. So we will see 70+MBps speeds till the drive reach this SMR region. In my case, for the 4TB drive, the last 350GB is showing such reduced speeds. Just to copy 15GB it took me a day.
 

rajil.s

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Thankfully none of my shucked drives are SMR. WD did pretty bad on that one.
 

6pack

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What is SMR region ? From your analogy, for a 2TB drive is it last 175GB ? Any thumb rule to calculate this ?
SMR region is just my own made up word.

This is just my unverified unsubstantiated claim. I came to that conclusion after getting varied speeds throughout the drive. Probably each disk has SMR on it throughout the entire platter or it may be confined to some region so that people don't send the drives back after doing a test in crystaldiskinfo thinking the drive is DOA and not giving the claimed SATA 6 speeds.

This is what I think the drive manufacturers are doing. Instead of using 4 platters for a 4TB drive, they are using 3 platters with a 20% disk space increase per platter using SMR tech. You get the same 3.6TB space for same price while they save money.

I don't have any thumb rule. Take your own conclusions from the following.

I've seen the copy and read speeds go down to those KB speeds when the drive was around 1 or 1.5TB (happened like a year back and I thought the drive was bad) & 3.5TB filled up. So I'm guessing probably around each platter end points. Rest of the space, I got 60-70MBps speeds for both copy paste.

Let's say the entire platter is an SMR drive. Then the drive should give the same copy and write speeds throughout the entire drive since it's a hardware feature. There should be no low copy or read speeds throughout the entire drive since the drive hardware chip does all the read write buffering etc. Or the entire drive should suffer from low copy and read speeds.

Lastly, look at the old PMR drives we have at home. They give about the same copy speeds whether the drive is empty or full. I've seen this with old drives having entire drive full and just 4-5GB free space remaining and if you copy to it you will still get close to 40-50MBps speeds.
 

6pack

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Seagate Engineer in 2018:/all the HDD vendors are now shipping SMR..." "all of them have been shipped kind of stealthily" -

 

logistopath

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Good info.. Learnt something new today! Missed this thread earlier.

List of SMR drives known to the community:

Manufacturer - WidthModel NoModel NameTypeNotes
WD - 3.5"WD20EFAX2TB WD RedDM-SMR(1) and (4), EFRX is CMR
WD - 3.5"WD30EFAX3TB WD RedDM-SMR(4), EFRX is CMR
WD - 3.5"WD40EFAX4TB WD RedDM-SMR(1) and (4), EFRX is CMR
WD - 3.5"WD60EFAX6TB WD RedDM-SMR(1) and (4), EFRX is CMR
WD - 3.5"WD20EZAZ2TB BlueDM-SMR(4), EZRZ is CMR
WD - 3.5"WD30EZAZ3TB BlueDM-SMR?, EZRZ is CMR
WD - 3.5"WD40EZAZ4TB BlueDM-SMR?, EZRZ is CMR
WD - 3.5"WD60EZAZ6TB BlueDM-SMR(4), EZRZ is CMR
WD - 3.5"WD40EMAZ4TB ElementsDM-SMR(12)
WD - 3.5"WD60EMAZ6TB ElementsDM-SMR(12)
WD - 3.5"WD60EDAZ6TB My BookDM-SMR(14)
Seagate - 3.5"ST2000DM0052TB BarracudaDM-SMRInferred from (8)
Seagate - 3.5"ST2000DM0082TB BarracudaDM-SMR(2)
Seagate - 3.5"ST3000DM0073TB BarracudaDM-SMRInferred from (8)
Seagate - 3.5"ST4000DM0044TB BarracudaDM-SMR(2)
Seagate - 3.5"ST5000DM0035TB BarracudaDM-SMR2TB platter as per (15)
Seagate - 3.5"ST6000DM0036TB BarracudaDM-SMRInferred from (8)
Seagate - 3.5"ST8000DM0048TB BarracudaDM-SMR(2)
Seagate - 3.5"ST5000DM0005TB DesktopDM-SMR(2)
Seagate - 3.5"ST5000AS00115TB ArchiveDM-SMR(3)
Seagate - 3.5"ST6000AS00026TB Archive v2DM-SMR(3)
Seagate - 3.5"ST8000AS00028TB Archive v2HA-SMR(3) and (10)
Seagate - 3.5"ST8000AS00038TB Exos (Archive v3)DM-SMR(2)
Toshiba - 3.5"HDWD240UZSVA4TB P300 DesktopDM-SMR(11)
Toshiba - 3.5"HDWD260UZSVA6TB P300 DesktopDM-SMR(11)
Toshiba - 3.5"DT02ABA4004TB DT02(-V)DM-SMR(11)
Toshiba - 3.5"DT02ABA6006TB DT02(-V)DM-SMR(11)
HGST - 3.5"DC HC600 Series14TB, 15TB and 20TB UltrastarHM-SMR(9)
------------
Toshiba - 2.5"HDWL1101TB L200 SlimDM-SMR(11)
Toshiba - 2.5"HDWL1202TB L200DM-SMR(11), see also list at (18)
Toshiba - 2.5"MQ04ABF1001TB MQ04DM-SMR(11)
Toshiba - 2.5"MQ04ABD2002TB MQ04DM-SMR(11)
WD - 2.5"WD9000LPZX900GB BlueDM-SMR(16)
WD - 2.5"WD10SPZX1TB BlueDM-SMR(4), also as HGST Travelstar, see (20)
WD - 2.5"WD10SPWX1TB BlueDM-SMR(16)
WD - 2.5"WD10SPSX1TB BlackDM-SMR(4)
WD - 2.5"WD20SPZX2TB BlueDM-SMR(4)
WD - 2.5"VariousNot For ResaleDM-SMRList at (17)
Seagate - 2.5"ST1000LM0481TB BarracudaDM-SMR(7), see also list at (19)
Seagate - 2.5"ST2000LM0152TB BarracudaDM-SMR(7), see also list at (19)
Seagate - 2.5"ST3000LM0243TB BarracudaDM-SMR(7), see also list at (19)
Seagate - 2.5"ST4000LM0244TB BarracudaDM-SMR(7), see also list at (19)
Seagate - 2.5"ST5000LM0005TB BarracudaDM-SMR(7), see also list at (19)

Got the above info from https://www.ixsystems.com/community/resources/list-of-known-smr-drives.141/. Credits go to the user Yorick who had compiled the list. Please check the primary source for references in the last column.
 

Veek M

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SMR Drives

The problem with SMR drives is that when you overlap the tracks like this, it means that there’s no way to write to just a single track without affecting the data on nearby tracks. Writing data to an SMR drive requires that the drive scan multiple tracks at once and then rewrite them. There’s a significant performance penalty for doing so, and that’s not the only issue with SMR drives.

Standard hard drives are built using PMR, or perpendicular recording. In an SMR drive, each track is partly laid over the next, forming a structure that looks like the shingles of a roof. The advantage of this method is that it allows for significantly higher data densities in the same physical platter.

According to Western Digital, the 8-14TB drives they sell are all based on PMR, while the 2TB-6TB parts are all SMR drives. The performance difference between the two is significant, with the 2TB -6TB drives in the 150MB/s to 180MB/s range, while the 8TB-14TB drives run at 198MB/s to 215MB/s. While SMR drives are cheaper to manufacture than PMR drives, none of the savings is being passed on to customers as far as we can tell.


Public Seagate documentation for these Barracudas and the Desktop HDD do not mention SMR. For example,