What's your Unused Reserved Block Count for Crucial MX500?

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pinoy

Limp Gawd
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I just got two 500 GB Crucial MX500 SSDs. When I check SMART one drive says Unused Reserved Block Count is 44 while the other drive is 37. Both are new drives and shows only 1 power cycle. I go to Crucial's website and of course they confused me even more:


"Attribute 180: Unused Reserved Block Count (Available Spare Blocks on PCIe SSDs)

Again, as the name implies, this is the count of extra blocks available to be used in case bad blocks need to be retired.
This number varies based on the underlying NAND architecture, the firmware architecture, and the user capacity of the drive,
but it usually starts in the thousands.

This number decreases as the number of retired blocks increases. When Attribute 180 reaches 0, the firmware will place
the SSD in read-only mode. The SSD will not be usable as a normal drive, but the user should be able to retrieve stored
data and transfer to a new device. It is strongly advised that if this number should get below 100 or so, the drive should
be replaced."
 
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Are you looking at the 'friendly' data or the raw data?

I'm running an MX300 which is probably a bit different and it's fairly old, but for attribute 180 (0xB4) it shows current 0, worst 0, threshold 0 in the friendly values, and then a raw value of 0x69D (1693). Usually the raw numbers are more useful than the friendly numbers.
 
I'm using Crucial's Storage Executive software to read SMART so it's showing user readable data.
 
pinoy said:
I'm using Crucial's Storage Executive software to read SMART so it's showing user readable data.
Click to expand...
I don't have any experience with that particular suite of software. Although I think I may have an MX500 lurking around somewhere. Anyway, are you suspecting something is wrong with the drives?
 
My two 1TB MX500's say 41 and 47 respectively, linux smartctl -a raw values. A pair of slightly older 500GB MX500's say 43 and 37. I guess that attribute 180 doesn't actually mean what the description would seem to imply.
 
I don't suspect anything wrong with my new drives. Benchmarks are good. Temperatures are good. It's just the discrepancy in that stat from two seemingly identical drives and Crucials explanation.
 
the count should be higher than that. the mx300s we have at work show ~2000 reserved blocks...
 
My MX500's aren't new, but they aren't all that used either. I suppose there must be a significant difference in what that number means as compared to the MX300.
 
So, I found a Crucial MX100 256GB (CT256MX100SSD1) drive in an old laptop. I loaded up the storage executive software:

180 - unused reserved block count - 2159 blocks
 
pinoy said:
I just got two 500 GB Crucial MX500 SSDs. When I check SMART one drive says Unused Reserved Block Count is 44 while the other other drive is 37. Both are new drives and shows only 1 power cycle. I go to Crucial's website and of course they confused me even more:
Click to expand...
change it to decimal,, use HDD sentinel once opened click on smart tab and right click on any smart field and click decimal, it should change to a number around 46 ish

most ssds already have bad pages that are mapped out at production (some older SSDs used to actually tell you the number of badblocks from new, i guess they removed it as made to many support questions) on the MX500 it can have more or less than 46 due to bad nand blocks been pre mapped out at production
 
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