Intel SSD shows total NAND writes and total host writes, with two very different figures

Feb 25, 2011
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Like the first reply mentioned, that's write amplification.

https://en.wikipedia.org/wiki/Write_amplification

Because flash memory must be erased before it can be rewritten... the process... results in moving (or rewriting) ... data ... more than once. ...rewriting some data requires an already used portion of flash to be read, updated and written to a new location... much larger portions of flash must be erased and rewritten than actually required by the amount of new data.

Think of unloading a dishwasher, except when you put a plate away, you have to take ALL the plates out, sort and organize the dishes, and then put them all back into the cabinet, every time. So you put away a lot more dishes than you take out of the dishwasher.

It is caused by how SSDs and NAND work but doesn't really have anything to do with MLC/TLC. (It's dependent on the writable block size.)

If the SSD is in your computer, you can get the model number in the device manager.
 

mikeymikec

Lifer
May 19, 2011
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Except that the 'write amplification' in this Intel SSD's case is 32 times higher not 2/3x.

The SSD isn't in my machine.

Another possibility is that CrystalDiskInfo is misreporting say the NAND figure or that the SSD is misreporting it.
 

Charlie22911

Senior member
Mar 19, 2005
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Well it’s not impossible... put that SSD in a system with barely sufficient RAM, with a page file on the SSD; that’ll do the trick.
 

mikeymikec

Lifer
May 19, 2011
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Well it’s not impossible... put that SSD in a system with barely sufficient RAM, with a page file on the SSD; that’ll do the trick.

The laptop is less than 1yo, 4GB RAM, light use. It may have run low on RAM once or twice.
 
Feb 25, 2011
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Except that the 'write amplification' in this Intel SSD's case is 32 times higher not 2/3x.

The SSD isn't in my machine.

Another possibility is that CrystalDiskInfo is misreporting say the NAND figure or that the SSD is misreporting it.

Oh, missed that.

Probably CrystalDiskInfo misreporting. I'd like to see the SMART data and whatnot, but if it's not available to you, *shrug*

The laptop is less than 1yo, 4GB RAM, light use. It may have run low on RAM once or twice.
A system w/ 4GB of RAM is going to be running low on ram all the time; anything with a web browser doesn't count as "light" use anymore.
 

Charlie22911

Senior member
Mar 19, 2005
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Age of the system isn’t a very informative metric on its own, how many power on hours does the drive report? If it’s been idling 24/7 with several programs open in the background fighting for resources, making tiny writes to the page file...
 

Glaring_Mistake

Senior member
Mar 2, 2015
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On an SSD that's less than a year old, reported by CrystalDiskInfo:

Total Host Writes: 137GB
Total NAND Writes: 4403GB

I googled it:
https://forums.sandisk.com/t5/All-Other-SanDisk-SSD/Host-writes-vs-total-NAND-writes/td-p/337243

So the disparity is caused by the cell technology? Would that make this SSD TLC then?

Sadly I didn't take a note of the full SSD model number to check its specs.

I know you say that the drive is not even a year old but still could it be an Intel 530 or 535?
Because those had major problems with write amplification something that was supposedly later fixed in an update.