This might be problem with the driver that I thought it was but after trying every thing like using new sata cable, intel/generic/raid drivers, nothing helped. drive shows up in bios after restart but when cold boot the drive disappears. windows gives explorer.exe error. this all happens when booting from my 970 evo as a boot drive…
Edit: I plug it to asmedia 6G and so far no problem.
So problem solved? Update your motherboard BIOS if you continue to have issues, if you’re on older BIOS this could cause problems like that.
If this is NVME SSD, and you need to boot from it, you may need BIOS mod before you can do that.
Thank you for reply…
Bios 4901is latest moded with nvme and 970 Evo booting fine into windows. But 850 evo ssd that connected to Intel 6G port via cable gets missing when cold boot.
might be x79 bug that prevent sata ssd connected to Intel port. I tried Ahci , raid, drives but still having problem reconize sata drive.
850 Evo is secondery sata data drive…
Yes, it might be buggy BIOS issue. Try another port, preferably not the last two 5/6 or 4/5 depending on how your board labels them for the Intel ports.
Make sure it’s Intel port, not Marvell or J.Micron, those are buggy for SSD.
board has only 2 Intel 6G ports. I tried both. It has 2 Asmedia 6G ports where the ssd works fine but half the speed of Intel ports.
Still testing it will see what’s come up…
Ohh yes, sorry I forgot X79 only has two Intel 6Gb/s ports
digging some more into it today…
In device manager Standard Sata Ahci controller now show yellow sign with "This device cannot start code 10" An I/O adapter hardware error has occurred.
I remember updating board ME Firmware from 8.1.51.1471 > 8.1.65.1586. dont think that might be the problem. 850evo works fine when connected to asmedia with in-box driver.
So the problem is with intel ports.
Im also thinking that intel SATA might be conflicting with 970evo as a boot drive
So I disconnect sata cable from mobo today and surprisingly the error still occurred as above.
Seems this driver conflict with nvme or chipset unable to switch on Ahci adapter on board.
I/O error is always bad sign with SSD 
99% of time the drive is dead or soon to die. I would RMA the drive if possible.
For the device manager error, uninstall that device and reboot, see if windows will reinstall it properly. If not, reinstall chipset driver package, and see if that helps, not likely but sometimes it can.
Since you updated ME, are you sure the ME FW is not corrupted? Check main BIOS page and see if you can see ME FW version (Some BIOS don’t show this), but if you see N/A or 0.0.0.0 then it’s currpted ME FW.
If your BIOS does not show this info, download HWINFO64 and on the large window on left side, expand motherboard and find ME area, inside that check the ME Firmware version and be sure it shows a correct version and not N/A or 0.0.0.0.
ME showing in bios fine with ver thats been updated.
why still get i/o error after I completely disconnect it?
Good ME Version is showing properly! It is strange about the I/O error, maybe you have bad SATA slot, or dying SB? Did you try what I mentioned about uninstalling from device manager and deleting driver, then reboot and reinstall INF driver package too?
Does this occur if you now reflash stock BIOS too?
tried all what you have mentioned.
seems its modded bios with nvme support. this all started since 970 evo installed.
installed and Booted from 850 all fine even with nvm. so it seem somehow window been corrupted when switching sata drivers , and refuse to activate ahci intel port. there is permanent yellow exclamation sign with, intel c600/x79 ahci sata controller,tried melwarebyte,sfc scan just in case
I’m so reluctant to reinstall.
is there any other way to activate sata controller
Which different SATA drivers did you install and how did you do it?
According to my experiences you can replace the in-use Intel AHCI/RAID driver as often as you want without any problem, if you
a) take the "pure" driver and install it from within the Device Manager and
b) only choose drivers, which do support the HardwareIDs of the on-board Intel SATA Controller.
The on-board SATA Controller can only be activated from within the BIOS.
I use "let me pick to update" within device manager when switching from RST/IRSTe drivers from here for x79 chipset.
I switched back to standard intel ahci controller within BIOS but exclamation mark still there no matter which driver I install.
How did you update the ME firmware? (FWUpdLcl or flashing the ME or updating or flashing a complete Bios?)
When the controller even with disconnected drive has an exclamation mark in Windows- is a normal SATA drive that’s connected to one of the Intel SATA ports showing up/ being recognized in Bios?
Is this a Windows problem or is this part of the chipset not correctly initialized aready at boot? (There are settings in ME that can affect SATA ports, too)
Can you run a MEInfo -verbose and a MEManuf -verbose (=>Intel ME System Tools v8 r3 - (2017-11-19) in this thread)
think I used ME flash only. no drive is connected with intel sata that has problem. Asmedia sata port works just fine with standard ahci controller with MS generic driver.
seems window problem but will use that commands to check further
memanuf -verbose
error 9405 intel internal communication error <epid gid>
epid group id 0
epid gid check passed
memanuf test passed
edit: pull the triger and Reinstalled win8 will see how it goes