High very high WAF (write amplification factor)

I own a few SSd Plus 120 and 240 gigs drives.

I am amazed how high is my WAF on a 240 Gb drive (firmware z220), over 5 already and keeps increasing.

Lifetime writes from host are 1267 Gbs with 6901 Gbs of nand writes (E9 smart attributed, 233 ID in sandisk dashboard)

This is my Win7 OS drive, nothing special going on on it. I’ve disabled ddefrag schedule and disabled windows search service.

 My other 120 Gb drive (firmware u210), which is newer, has a WAF around 3.5. High but not as bad… May get worse though…

What is going on ? Is this normal to have a WAF of 5.5 after only 1.3 Tb written ?

Thanks for your lights. Best.

Hi bolc,

In your dashboard, have you noticed any life drop? And when you check your SMART report, have you seen any bad blocks, UECC errors or program fails ?

The reason for WAF may vary, if you see a substantial increase in any of the above SMART attribute you can contact our support at 1-866-SANDISK and we will take a closer look at your case, if not, I think your drive is functioning as expected and performing background operation, and it should not effect your usage.

Thanks for the reply.

No errors, no life drop (0.01% media wearout indicator) but the WAF keeps getting higher and higher. Above 6 now.

I have sent back the drive to Amazon where I bought it. I didn t notice it was a Wharehouse deal and I received a drive with 900x starts with 870 unpected shutdown… plus more than 1 Th written and 6 Tb written on the NAND.

My SSd Plus 120 gb is a rockstar in comparison: WAF of 1.25 for about the same 1 Tb written. Small caapcity but 5 times better WAF… so 2.5 x more TBW… Gofigure …

in another SSD plus, WAF is at 3.5.  Both have the same U210 firmware.

I think SSD makers have no clues how statistically good/bad are the SSD they are producing…

On another SSd I bought for my stepdad, the WAF is alreay at 40 !!! for only 450 Gb written the NAND is at 17+ Tb!!!

This is incredible.

Wearout indicator is at 0.05 % for a drive switched ON only 84 hrs… (indexation, windows search and derag are off)

SSD Aldo.png

SSD Aldo2.png

At this rate the drive will crash in less than a year…

Thank you Bloc, we will bring this case to our engineering and discuss, meanwhile, can you check your private mail and contact us ?

Thank you

Thank you.

I replied to your PM.

I also noticed that the Total Bad Blocks is at 16



The disk is now at ~500 Gb written for ~20+ Tb NAND written.

Thanks bolc,

I have wrote you an email regarding your case, you can continue discussion with me by replying that email.

for more infohttp://www.overclock.net/t/1573245/sandisk-ssd-plus-write-amplification

Hi Tuzik,

I have sent you an private message to better assist you.

Hi Chushi,

Thank you for your help.

I did the RMA request of the previous drive (which was received in Sandisk center in CZ Republic) and now wait for a replacement.

In the meantime I mounted another SSD Plus to keep the pc working, and this 120 Gb drive, which ran absolutely fine on another pc equipped with ICH10R chipset (Asus P5Q board) with a WAF factor of 3-4 increasing slightly overtime, and about 2 months old but rearely used, went up like hell on this machine.

After 4 days of use on the Nforce 610i chipset of the MSI P6NGM-L, with AHCI on in the bios and active ; indexing, defrag and windows search services all OFF, it was at 7000 Gb NAND written for 500 Go on the host. Will connect at distance to the machine to get the latest crystaldisk / dashboard screenshots.

Any ideas what can be responsible on the Nvidia chipset / windows 7 installation ? Or is it just a coincidence ? (the same Win7 installation was cloned from the old SSD to this one).

I tried in the past to use Nvidia ahci driver or ahci microsoft generic drivers, same results in terms of waf increase (but microsoft generic give much faster transfer rates so I kept those).

I plan to change the motherboard with a ICH9R board hoping it would be working well like with ICH10R ; on Z97 chipset I have 0 problems. But this will be in 3 weeks or so by the time I go back to my father in law…

Thanks for your help.

Best Regards

for the record, it was 6700 Gb on 5/13, now on 5/17 around 9500 for 488 Gb written (this one barely moved). Double checked that defrag, windows search and indexation all off. The media wearout of 0.02% is low enough, hope I will be able to change the motherboard quick enough not to reach too many NAND written (if that solves the problem…)



Hi Bolc,

Please reply to your support email with the drive information that you see similar issue, we may need to replace that one for you too. This issue happen very rarely, but very sorry you are seeing multiple drives with this issue.

Hi Chushi,

Thanks, I have done a reply.

Let me know what kind of info you need ?


Nforce 610i chipset… TRIM Working?

Probably aggressive
cleaning SM2246XT

Trim sure is working. At least sandisk dashboard and other softwares say so

What od you mean by Probably aggressive cleaning SM2246XT …?

I also have Plus with Z22000RL fw, and found my WA now about 20! 10TB host writes and sic! 200TB NAND writes actually.

SanDisk SSD dashboard (actual version) definitely wrong about Media Wearout percentage. It prints 0,32% but actualy it is 32% of total endurance.

To correct this, we need edit SMART database in Dashboard, and change in smart folder in file smart_list.xml


  <ref fname=“aphrodite2_generic.xml” matchType=“prefix” length=“8” fwprefix=“Z2” version=“1.1” />


  <ref fname=“aphrodite2_generic.xml” matchType=“prefix” length=“8” fwprefix=“Z2” version=“1.4” />

and in aphrodite2_generic.xml


<smart version=“1.3”>

  <aname id=“230” raw=“1:0” format=“XH.XL %”>Media Wearout Indicator</aname>


<smart version=“1.4”>

  <aname id=“230” raw=“1:0” format=“XL %”>Media Wearout Indicator</aname>

but this doesn’t fix endurance on the main product page in dashboard, only corrects it in advanced smart view.

The same problem as the rest, SSD too much writes in NAND. Maybe it will be possible to solve this problem in a future firmware update, otherwise the drive is not likely to serve the term of guarantee. Disappointed in this drive. diskinfo.jpg diskinfo.jpg

I think this drive will need to be replaced. I would recommend contacting sandisk support for replacement.