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fzabkar

Seagate 12TB and 14TB HDD reviews -- comments

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I have several comments relating to the following two reviews, and to omissions in Seagate's technical documentation.

https://aphnetworks.com/reviews/seagate-barracuda-pro-st12000dm0007-12tb (Review - Seagate BarraCuda Pro ST12000DM0007 12TB)
https://aphnetworks.com/reviews/seagate-ironwolf-pro-st14000ne0008-14tb (Review - Seagate IronWolf Pro ST14000NE0008 14TB)

https://www.seagate.com/www-content/datasheets/pdfs/ironwolf-pro-14tb-DS1914-7-1807US-en_US.pdf (IronWolf Pro datasheet)
https://www.seagate.com/www-content/product-content/ironwolf/en-us/docs/100835984b.pdf (Seagate IronWolf Pro Serial ATA Product Manual, Rev. B )
https://www.seagate.com/www-content/product-content/ironwolf/en-us/docs/100851637c.pdf (Seagate IronWolf Pro SATA Product Manual, Rev. C)
https://www.seagate.com/au/en/internal-hard-drives/hdd/ironwolf/ (Seagate IronWolf / IronWolf Pro product page)

The 12TB review states that "with these high-density platters using traditional perpendicular magnetic recording technology as opposed to performance-penalizing technologies like shingled magnetic recording, this should translate to great performance in our benchmarks."

Perpendicular magnetic recording (PMR) refers to the way in which bits are laid down, either horizontally or vertically (PMR).

Shingled magnetic recording (SMR) and conventional magnetic recording (CMR) refer to the way that the tracks are laid down, either side by side (CMR) or overlapping (SMR).

Therefore a drive can be both SMR and PMR -- these terms are not mutually exclusive.

Strangely, neither Seagate's product manual or datasheet makes any reference to SMR or CMR. Instead one needs to go to the product page:

"Built with conventional magnetic recording (CMR), IronWolf and IronWolf Pro drives deliver the consistent performance you need."

Similarly, there is no mention of helium in any of the abovementioned documents or product page, yet these drives clearly are helium models, as the aphnetworks reviews point out.

In the following image of the IronWolf PCB, Seagate highlights the RV (rotational vibration) sensors, but doesn't point out the bank of 15 capacitors. These capacitors would suggest that the drive has some kind of data loss protection in the event of power loss. As before, there is no mention of such protection in the above documents or on Seagate's product page.

https://www.seagate.com/files/www-content/product-content/ironwolf/images/rv-sensor-float-right-row3-570x500.png
 
I can't see whether there are multiple read channels in either of the aphnetworks PCB images. If these do exist, then the drive(s) should support TDMR (two dimensional magnetic recording). Once again, there is no mention of TDMR in Seagate's documents or product page.

Another thing that may be of interest is that Seagate's newer PCBs have electronic fuses, which is a welcome improvement from the usual TVS diodes.

The 14TB review states that, "as with all NAS drives, the Seagate IronWolf Pro is ERC enabled. ERC stands for 'Error Recovery Control', which is Seagate's name for a feature that limits a hard drive's error recovery time to seven seconds (Western Digital calls it TLER; HGST calls it CCTL)."

In fact the ERC feature has been part of the official ATA standard for quite some time, so the name is not really Seagate's. Tools such as HDAT2 can set the ERC read/write timeout values, but AFAIK these parameters are usually volatile, ie they don't survive a power cycle.

Most helium drives report the helium level via SMART attribute 22 (16h). Could I respectfully suggest that each review include a SMART report from a tool such as CrystalDiskInfo? I find this to be the most useful Windows SMART tool (HD Tune is poor in this regard). GSmartcontrol is another good tool (perhaps better).

FYI, here is a discussion about helium drives, TDMR, etc:

https://forum.hddguru.com/viewtopic.php?f=1&t=37159&start=60

 

Edited by fzabkar
correction

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1 hour ago, fzabkar said:

I have several comments relating to the following two reviews, and to omissions in Seagate's technical documentation.

https://aphnetworks.com/reviews/seagate-barracuda-pro-st12000dm0007-12tb (Review - Seagate BarraCuda Pro ST12000DM0007 12TB)
https://aphnetworks.com/reviews/seagate-ironwolf-pro-st14000ne0008-14tb (Review - Seagate IronWolf Pro ST14000NE0008 14TB)

https://www.seagate.com/www-content/datasheets/pdfs/ironwolf-pro-14tb-DS1914-7-1807US-en_US.pdf (IronWolf Pro datasheet)
https://www.seagate.com/www-content/product-content/ironwolf/en-us/docs/100835984b.pdf (Seagate IronWolf Pro Serial ATA Product Manual, Rev. B )
https://www.seagate.com/www-content/product-content/ironwolf/en-us/docs/100851637c.pdf (Seagate IronWolf Pro SATA Product Manual, Rev. C)
https://www.seagate.com/au/en/internal-hard-drives/hdd/ironwolf/ (Seagate IronWolf / IronWolf Pro product page)

The 12TB review states that "with these high-density platters using traditional perpendicular magnetic recording technology as opposed to performance-penalizing technologies like shingled magnetic recording, this should translate to great performance in our benchmarks."

Perpendicular magnetic recording (PMR) refers to the way in which bits are laid down, either horizontally or vertically (PMR).

Shingled magnetic recording (SMR) and conventional magnetic recording (CMR) refer to the way that the tracks are laid down, either side by side (CMR) or overlapping (SMR).

Therefore a drive can be both SMR and PMR -- these terms are not mutually exclusive.

Strangely, neither Seagate's product manual or datasheet makes any reference to SMR or CMR. Instead one needs to go to the product page:

"Built with conventional magnetic recording (CMR), IronWolf and IronWolf Pro drives deliver the consistent performance you need."

Similarly, there is no mention of helium in any of the abovementioned documents or product page, yet these drives clearly are helium models, as the aphnetworks reviews point out.

 

Typically PMR and CMR is used interchangeably, so in those reviews I preferred to use PMR over CMR until a couple of years ago to distinguish with LMR. I am not aware of anyone who uses SMR and PMR interchangeably given SMR is an extension of PMR.

Quote

In the following image of the IronWolf PCB, Seagate highlights the RV (rotational vibration) sensors, but doesn't point out the bank of 15 capacitors. These capacitors would suggest that the drive has some kind of data loss protection in the event of power loss. As before, there is no mention of such protection in the above documents or on Seagate's product page.

https://www.seagate.com/files/www-content/product-content/ironwolf/images/rv-sensor-float-right-row3-570x500.png
 
I can't see whether there are multiple read channels in either of the aphnetworks PCB images. If these do exist, then the drive(s) should support TDMR (two dimensional magnetic recording). Once again, there is no mention of TDMR in Seagate's documents or product page.

Another thing that may be of interest is that Seagate's newer PCBs have electronic fuses, which is a welcome improvement from the usual TVS diodes.

The 14TB review states that, "as with all NAS drives, the Seagate IronWolf Pro is ERC enabled. ERC stands for 'Error Recovery Control', which is Seagate's name for a feature that limits a hard drive's error recovery time to seven seconds (Western Digital calls it TLER; HGST calls it CCTL)."

In fact the ERC feature has been part of the official ATA standard for quite some time, so the name is not really Seagate's. Tools such as HDAT2 can set the ERC read/write timeout values, but AFAIK these parameters are usually volatile, ie they don't survive a power cycle.

Most helium drives report the helium level via SMART attribute 22 (16h). Could I respectfully suggest that each review include a SMART report from a tool such as CrystalDiskInfo? I find this to be the most useful Windows SMART tool (HD Tune is poor in this regard). GSmartcontrol is another good tool (perhaps better).

FYI, here is a discussion about helium drives, TDMR, etc:

https://forum.hddguru.com/viewtopic.php?f=1&t=37159&start=60

Enjoy.

qLOi4Bs.png

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The SMART report doesn't have a helium level attribute. It seems that Seagate really didn't want the world to know that the drive was a helium model.

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On 5/18/2020 at 5:57 PM, TL6MT said:

16724 hours and 14 power cycles?

Probably used in a NAS - the way it's meant to be Used

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