Samsung SSD EVO 850, insanely low random read/write

[EnafAequi]

Hello, the picture above shows it all,
suddenly my random read/write performance went from ~40000 to ~4000,
90% lost in performance

any idea what might have caused that?

it's been several days since my computer's performances took a hit, I've looked into it but I'm no specialist.

Edit :
- I'm on SATA 2, but it's irrelevant, previous high IOPS Benchmark were on the same hardware with SATA2
- Computer software is clean, I use CCleaner, SuperAntSpyware & Malwarebytes, and take good care of my software
- drive temperatures are ok
- drive available space is 60Go

someone with similar Benchmark, SATA 2 & problem found a solution : reactivating the "Write Cache Buffer"
http://www.tomshardware.co.uk/answers/id-2133167/low-iops-ssd-samsung-840-pro-128gb-solved.html

I'll give it a shot tonight
I'll also check that TRIM is active

Edit 2 :
see last news below

 

[entropy4money]

I would suggest you contact Samsung about this. They had a similar problem occur with the Evo 840

 

[EnafAequi]

I've done it by email 5 days ago, no answer yet

I've fallow the steps to optimize here :
http://www.thessdreview.com/ssd-guides/optimization-guides/the-ssd-optimization-guide-2/
and tried to deactivate/reactive samsung rapid mode

now windows won't start, blue screen after windows loading => restart and so on
I manage to start in safe mode,
I think i'll format my ssd, and reinstal windows on it,

I've used my hardware for 6 years without any blue screen ever, this is starting to piss me off, big time

 

[entropy4money]

How old is your SSD? is it still under warranty?. If it is still under warranty and Samsung hasn't contacted you yet, I suggest you call them if you can and go through RMA as soon as you can. If it isn't under warranty your only alternative is to wipe the drive.

Make sure you wipe the drive and not format it. What I talk about wiping the drive, I am talking replacing every single bit in the memory by a 0. If this fails, it means that the SSD is damaged beyond anything you can do, and you should get a replacement. If this doesn't fail, then your SSD is most probably in good condition. You can do a full wipe using gparted from any Linux distro, or the Gparted bootable version. You can also do it from a Linux terminal. And I believe there is also a way to do it from command prompt using the windows system repair disk.

After you do the full wipe, it won't hurt to run a full check on the disk for errors. I am not sure if this would be necessary though.