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SanDisk User
Posts: 22
Registered: ‎03-27-2014
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Extreme II SMART parameter specification sheet?

Hello,

 

I recently purchased a Sandisk Extreme II SSD and I would like to know if there is a SMART parameter specification sheet for this drive available somewhere as other SSD manufacturers often provide. I'm trying to write an SSD monitoring application for Linux and for best results it would be useful for me to know what all SMART parameters for this drive mean exactly. Thanks in advance.

SanDisk User
Posts: 61
Registered: ‎05-03-2012

Re: Extreme II SMART parameter specification sheet?

Good luck with that, I can't find a comprehensive datasheet for the SanDisk Extreme II SSD, such as those provided by Intel for their SSDs.

 

I imagine this won't help much, but the SanDisk SSD Toolbox will at least display the SMART attributes SanDisk makes available to the public.

 

Other programs that display SMART atttributes show more than the SanDisk Toolbox displays, but if they are valid or not, who knows?

SanDisk User
Posts: 22
Registered: ‎03-27-2014

Re: Extreme II SMART parameter specification sheet?

[ Edited ]

Well, of course I would like to know what the attributes not listed by the Sandisk toolbox are (which CrystalDiskInfo lists as "vendor specific") Smiley Happy

I might have identified two, but I have no clue yet about most of them.

 

 

 

AD = Average NAND P/E count (although A6 could be too, need more writes to tell)

E9 = Total NAND Writes in GiB (which is neat as it allows to calculate the drive's write amplification together with Total Host Writes)

SanDisk User
Posts: 22
Registered: ‎03-27-2014

Re: Extreme II SMART parameter specification sheet?

[ Edited ]

With a bit of research I started filling up this SMART attribute name list for the Sandisk Extreme II SSD with Marvell 9178-based controller. It appears that attributes are grouped in a logical manner, which should help figuring out what they mean. The [?] symbol denotes that SanDisk does not provide information about those attributes in the ToolBox or anywhere else, and that therefore they are my own's best guess through observation.

 

 

Generic SMART parameters

05 - Retired Block Count [1 block = 4 MB]
09 - Power On Hours
0C - Device Power Cycle Count

 

Interface-level counters? (basing on SMART parameters for Marvell-based drives from other manufacturers)
A6 - [?]
A7 - [?]
A8 - [?] [This slowly increases as Host and NAND writes increase, but it does not seem to be linearly correlated with them]
A9 - [?]

 

Internal-level counters
AB - Program Fail Count
AC - Erase Fail Count
AD - [?] Average Block-Erase Count [P/E cycles]
AE - Unexpected Power Loss Count

BB - Reported Uncorrectable Errors

C2 - Temperature

D4 - [?]

 

Usage statistics - Internal
E6 - Life Curve Status [No idea about what this means. So far, its raw value increased by 3 for each block-erase count event]
E8 - [?] Percent Lifetime Remaining [%]
E9 - [?] Lifetime NAND Writes [GiB]

 

Usage statistics - Host
F1 - Lifetime Writes to Host [GiB]
F2 - Lifetime Reads from Host [GiB]
F3 - [?]

 

 

 

Micron/Crucial provide something like this, which helps big time:

M500: http://www.micron.com/-/media/Documents/Products/Technical%20Note/Solid%20State%20Storage/tnfd21_m50...

M550: http://www.micron.com/-/media/Documents/Products/Technical%20Note/Solid%20State%20Storage/tnfd22_m55...

 

Since they're based on the same controller, many of these parameters are exactly the same. However we cannot be sure until SanDisk confirms and/or provides similar documentation. Please help!

SanDisk User
Posts: 22
Registered: ‎03-27-2014

Re: Extreme II SMART parameter specification sheet?

[ Edited ]

Is the SMART parameter A8 related with the drive's lifetime Write Amplification Factor?

 

I'm monitoring that as well (by dividing NAND Writes by Host writes over time as they increase) and I found out that their curves are strongly correlated to each other:

 

Highlighted
SanDisk User
Posts: 22
Registered: ‎03-27-2014

Re: Extreme II SMART parameter specification sheet?

[ Edited ]

The new Sandisk Dashboard software (here: http://kb.sandisk.com/app/answers/detail/a_id/15108 ) provides all the information I needed under the SMART diagnostics tab. Thanks Sandisk! Although it would be nice if this information was more readily available (ie available directly from SMART parameter / the SSD firmware?):

 

 

 

Sandisk Extreme II (firmware: R1311)

  5 / 05 - Retired Block Count [1 block = 4 MB]
  9 / 09 - Power On Hours
 12 / 0C - Device Power Cycle Count

166 / A6 - Min W/E Cycle
167 / A7 - Min Bad Block/Die
168 / A8 - Maximum Erase Cycle
169 / A9 - Total Bad Block

171 / AB - Program Fail Count
172 / AC - Erase Fail Count
173 / AD - Average Erase Cycle
174 / AE - Unexpected Power Loss Count

187 / BB - Reported Uncorrectable Errors

194 / C2 - Current Temperature

212 / D4 - SATA PHY Error

230 / E6 - Percentage Total P/E Count XX.YY
232 / E8 - Spare Blocks Remaining [%]
233 / E9 - Total GB Written to NAND
241 / F1 - Total GB Written
242 / F2 - Total GB Read

243 / F3 - [?]