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.