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Newbie
Posts: 13
Registered: ‎04-12-2016
Accepted Solution

High very high WAF (write amplification factor)

[ Edited ]

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.

 

 

VIP
Posts: 79
Registered: ‎03-17-2016

Re: High very high WAF (write amplification factor)

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.

Newbie
Posts: 13
Registered: ‎04-12-2016

Re: High very high WAF (write amplification factor)

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...

Newbie
Posts: 13
Registered: ‎04-12-2016

Re: High very high WAF (write amplification factor)

[ Edited ]

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....

VIP
Posts: 79
Registered: ‎03-17-2016

Re: High very high WAF (write amplification factor)

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

Newbie
Posts: 13
Registered: ‎04-12-2016

Re: High very high WAF (write amplification factor)

Thank you.

I replied to your PM.

 

I also noticed that the Total Bad Blocks is at 16

Cheers

Newbie
Posts: 13
Registered: ‎04-12-2016

Re: High very high WAF (write amplification factor)

[ Edited ]

???

 

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

VIP
Posts: 79
Registered: ‎03-17-2016

Re: High very high WAF (write amplification factor)

Thanks bolc,

 

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

Newbie
Posts: 2
Registered: ‎05-08-2016

Re: High very high WAF (write amplification factor)

VIP
Posts: 79
Registered: ‎03-17-2016

Re: High very high WAF (write amplification factor)

Hi Tuzik,

 

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