# WD WD40NMZW 4TB - Any Good ?



## SalemCat (Apr 13, 2006)

Will a WD40NMZW work well as a BOLT upgrade ?

https://www.walmart.com/ip/WD40NMZW-11GX6S1-DCM-Western-Digital-4TB-USB-2-5-Hard-Drive/660788378

(BTW - I would not be purchased this refurbished unit from Walmart. eBay has them NEW for less money.)


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## m.s (Mar 8, 2007)

I wouldn't trust one. It's an SMR drive.


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## SalemCat (Apr 13, 2006)

m.s said:


> I wouldn't trust one. It's an SMR drive.


Oh darn it.

SMR are bad for TiVo.

Any other inexpensive recommendations ?


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## fcfc2 (Feb 19, 2015)

m.s said:


> I wouldn't trust one. It's an SMR drive.


Not a challenge, but an ask, do you have a reference for that info?


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## aaronwt (Jan 31, 2002)

m.s said:


> I wouldn't trust one. It's an SMR drive.


When did WD switch to using SMR with their 2.5" drives? The WD 3TB and lower 2.5" drives use PMR don't they?


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## SalemCat (Apr 13, 2006)

I thought SMR was exclusive to Seagate ?


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## m.s (Mar 8, 2007)

Buncha Googletards. Linky.


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## fcfc2 (Feb 19, 2015)

m.s said:


> Buncha Googletards. Linky.


Thanks so very much for your gracious and mature response.


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## SalemCat (Apr 13, 2006)

When all else fails (sort of), contact the Manufacturer.

*Thank you for contacting Western Digital Customer Service and Support. My name is Eli.

I understand that you want to know that WD Blue is an SMR drive or not. I will assist you with this.

Per your concern, I would like to inform you that WD blue is an SMR (Shingled magnetic recording) drive. 
*
Oh well.


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## sfhub (Jan 6, 2007)

SalemCat said:


> *Per your concern, I would like to inform you that WD blue is an SMR (Shingled magnetic recording) drive. *


Don't know if it means anything for longevity, but according the earlier link the WD SMR behaves differently from the Seagate SMRs performance-wise. The Seagate performance goes completely to crap once the cache runs out. The WD drives slow down but no where near what the Seagate do. This probably indicates different design for their SMR.


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## tommage1 (Nov 6, 2008)

SalemCat said:


> When all else fails (sort of), contact the Manufacturer.
> 
> *Thank you for contacting Western Digital Customer Service and Support. My name is Eli.
> 
> ...


Hmm, I was shopping for a 4TB drive the other day for my Roamio. I ALMOST bought a WD Blue but was unable to find any SMR data, glad I did not buy it (there are different model Blues though, wonder if they are ALL SMR?). I went with a Seagate ST4000DM005, almost bought an ST4000DM004 but found some info that the 004 could be SMR (004 is 2 platter, the 005 is 3 platters, and I found the 000 is 4 platters). The post I found was speculating that the 004 was SMR so don't know for sure.

I have heard that not only is it hard to find data on what drives are SMR the manufacturers have actually found "tricks" to CONCEAL if a drive is SMR. Spec sheets do not seem to show the info. I know there was a 4TB 2.5 Seagate drive people were trying in the Bolt, tests showed it was not SMR but turns out it actually is. I'm almost afraid to buy larger drives now for Tivos as it seems very hard to find info on if they are SMR or not.

Oh, how about WD Gold drives? They are enterprise drives, would think they might be PMR but it also says they are storage type drives so are they SMR also? With WD I guess would have to stick with Purple or Red, or is that safe?


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## tommage1 (Nov 6, 2008)

Ooh, I see the original post was for a 2.5 Blue (I was just searching for SMR type posts). So not sure if the 3.5 Blues are SMR (does anyone know?). Obviously the drive I was looking to buy was a 3.5 for a Roamio. However if anyone has any info on how to determine if a drive is SMR other than checking spec sheet (which has done me no good other than some showing how many platters) please inform, when shopping I don't always have time to contact manufacturers directly on multiple model numbers.


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## SalemCat (Apr 13, 2006)

tommage1 said:


> Ooh, I see the original post was for a 2.5 Blue (I was just searching for SMR type posts). So not sure if the 3.5 Blues are SMR (does anyone know?). Obviously the drive I was looking to buy was a 3.5 for a Roamio. However if anyone has any info on how to determine if a drive is SMR other than checking spec sheet (which has done me no good other than some showing how many platters) please inform, when shopping I don't always have time to contact manufacturers directly on multiple model numbers.


I highly recommend WD PURPLE AV drives.

I have two of the 4TB version (one in my Premiere), and so far (two years) they have been great.

And as AV Drives they never PARK (good).


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## aaronwt (Jan 31, 2002)

tommage1 said:


> Hmm, I was shopping for a 4TB drive the other day for my Roamio. I ALMOST bought a WD Blue but was unable to find any SMR data, glad I did not buy it (there are different model Blues though, wonder if they are ALL SMR?). I went with a Seagate ST4000DM005, almost bought an ST4000DM004 but found some info that the 004 could be SMR (004 is 2 platter, the 005 is 3 platters, and I found the 000 is 4 platters). The post I found was speculating that the 004 was SMR so don't know for sure.
> 
> I have heard that not only is it hard to find data on what drives are SMR the manufacturers have actually found "tricks" to CONCEAL if a drive is SMR. Spec sheets do not seem to show the info. I know there was a 4TB 2.5 Seagate drive people were trying in the Bolt, tests showed it was not SMR but turns out it actually is. I'm almost afraid to buy larger drives now for Tivos as it seems very hard to find info on if they are SMR or not.
> 
> Oh, how about WD Gold drives? They are enterprise drives, would think they might be PMR but it also says they are storage type drives so are they SMR also? With WD I guess would have to stick with Purple or Red, or is that safe?


Seagate is easy. They use SMR in their drives. Even their small capacity 1TB drives use SMR. And their 4TB and 5TB drives most definitely use SMR.


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## CIR-Engineering (Sep 24, 2017)

Great 4TB WD PMR drives from a very reputable seller on eBay. I have bought many and parking can be disabled.

WD40NPZZ

*New* WD GREEN WD40NPZZ 4TB IntelliPower 8MB 15mm SATA 6.0Gb/s 2.5" (Blue) | eBay

OR

WD GREEN WD40NPZZ 4TB IntelliPower 8MB 15mm SATA 6.0Gb/s 2.5" (Blue)*Light Use* | eBay

Disable parking:
PSA: WD BLUE WD40NPZZ

Best,
craigr


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## zangetsu (Jan 12, 2010)

why is SMR bad for TIVO ?

what is the largest capacity PMR drive that i can buy for a TIVO Bolt ? it has a 500 GB in it now.

are there any large capacity 2.5" PMR drives i can use in TIVO that are not seagate ?

thank you.


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## HerronScott (Jan 1, 2002)

zangetsu said:


> are there any large capacity 2.5" PMR drives i can use in TIVO that are not seagate ?


The one mentioned in this thread or are you trying to get one larger than 4TB? 

Scott


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## CIR-Engineering (Sep 24, 2017)

https://m.ebay.com/itm/WD-GREEN-WD40NPZZ-4TB-IntelliPower-8MB-15mm-SATA-III-2-5-Blue-Light-Use-TiVo/273315575878

This is the drive I use. "central_valley_computer_parts_inc" tends to move the price around on these drives often and right now it's more expensive than usual. You may want to wait until they put it on sale which the often do for $30-$20 less than it is right now. This drive supports disabling parking as well (see my thread on that). On WD drives, if the drive is 15mm thick it is most likely a PMR drive. There is also a 5TB version that comes up periodically.

craigr


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## zangetsu (Jan 12, 2010)

HerronScott said:


> The one mentioned in this thread or are you trying to get one larger than 4TB?
> 
> Scott


sorry i perhaps misunderstood that that drive was SMR and not PMR, i still do not understand why one is good and one is bad for tivo.

thank you for your answer.


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## HerronScott (Jan 1, 2002)

zangetsu said:


> sorry i perhaps misunderstood that that drive was SMR and not PMR, i still do not understand why one is good and one is bad for tivo.


I don't think anyone here knows (or can know) the answer. Here's the information on SMR drive technology on Wikipedia which also has references to other documents that you can read. I think we can only guess as to why SMR drives eventually seem to fail. It's possible the drives used are host-managed and TiVo's OS doesn't support SMR drives so although it works initially, it eventually breaks since the tracks are overlapped and it is not rewriting adjacent tracks.

Shingled magnetic recording - Wikipedia

*Shingled magnetic recording* (*SMR*) is a magnetic storage data recording technology used in hard disk drives (HDDs) to increase storage density and overall per-drive storage capacity.[1] Conventional hard disk drives record data by writing non-overlapping magnetic tracks parallel to each other (perpendicular recording), while shingled recording writes new tracks that overlap part of the previously written magnetic track, leaving the previous track narrower and allowing for higher track density. Thus, the tracks partially overlap similar to roof shingles. This approach was selected because physical limitations prevent recording magnetic heads from having the same width as reading heads, leaving recording heads wider.[2][3][4]:7-9

The overlapping-tracks architecture may slow down the writing process since writing to one track overwrites adjacent tracks, and requires them to be rewritten as well. _Device-managed_ SMR devices hide this complexity by managing it in the firmware, presenting an interface like any other hard disk, while other SMR devices are _host-managed_ and depend on the operating system to know how to handle the drive, and only write sequentially to certain regions of the drive

Scott


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## sfhub (Jan 6, 2007)

Theoretically SMR should just be slower, maybe slightly less life due to constant writes becoming constant write-read-write. I think there are some early growing pains with the tech though where some implementations have drastically less life, possibly the materials or distances between tracks did not have enough tolerances to stay stable over long term constant writes. Perhaps if they adjusted the track separation, materials, or head magnetic strength, coupled with some larger caching, then it can all be addressed.

IMO they don't really test new tech like the used to before going mainstream. Essentially lots of first year releases are actually public betas for the tech masquerading as finished products.


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