Dashboard,SMART index

I buy a 960 GB Sandisk Ultra II on 14/09/2016, and after a week mount on my notebook Lenovo.

It work good, speed read/write is good, for this i have cloned my old C on new C Sandisk Ultra II. My old C was full to 90-95%%

After this i use my notebook for work and fun every day for about 15 hours/day.

We think to October, November, December…3 month, 90 day.

Last days i see that SSD Life showed by Dashboard change to 99%. Ok, this work good i think, it can survive for 3 month for 100% = 300 month = 25 years of 50 years of life that normally are given to a 1TB SSD.

But if i see SMART index i see:

Power on hours: 951 = 10 hours/day for real total usage.

I work on last 50-60GB free of SSD (other 900GB was writen only 1 time) and i have 0 Reassigned NAND block, total bad block 1230, grown bad block 0, program fail block 0, NAND GB Written TLC 4270, NAND GB Written SLC 97, Total GB Write 7101.

On 90 day 7101 GB was 78 GB write every day. I have only 60 GB free on my SSD and sure i do not have write 7 TB of data. My entire set of HDD never joint 4 TB… and only on SSD for Dashboard program i have write x2 disk space?!

I do not know if NAND GB written TLC + NAND GB written SLC = Total GB Write.

Difference is 4TB vs 7 TB. It is normal?

Can be that SMART Index of Dashboard do not work good?

Only SSD Dashboard software see SMART attributes of this Sandisk SSD Ultra II.

Crystal Disk Info cant see SSD and his SMART attributes.

Hi Merovingio, 

The traffic reported on SMART total GB wirtten is different from user written data, because of a SSD term called write amplification, the SSD may doing background write for optimization, recycling, trim and other reason. Especially when you have the drive almost full, the drive’s firmware may try to optimize for performance and cause more than usual traffic. 

From the 0 reassigned block count, 0 grown bad block count and 0 error/fail I think the drive is in a healthy state, however if you see sudden dramatic increase of any of these attribute I would suggest you contact our support center and consider a replacement.

Hi Chushi, thanks for reponse.

What is the optimal occupation of SSD to reduce the write amplification do to recycling, trim, firmware optimization,…?

Write Amplification is a result from Garbage Collection, TRIM, Wear Leveling etc. which are all meant to extend the drive’s lifespan. 

There is no optimal way to reduce write amplification at this moment, if you are interested, please check this wiki page: 

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