Windows 10: W10 Recognizes My External SATA II Drive As SATA I - Why ?

I solved a similar problem in Win 7 by uninstalling an Advanced "6G" Storage Controller and letting Windows install its generic driver but I have no idea what to do in Win 10 because of the dumbed down way everything behind the scenes is displayed, which appears not to have anything remotely resembling such a thing.
Anyone else having similar issues? Or am I doomed with my now-almost-extinct 2009 Alienware machine?

:)

 

How to format a disk in windows 10 using Disk Management

Trying to format a blank external SATA drive for Windows 10 backup. Disk Management recognizes the drive, but greys out the Format option. ???

 

Have 4 x 3.o Gb ports and 2 x 6 Gb ports. How do they differ?

A SATA II interface has a maximum throughput of 3 GB/s. A SATA III interface has a maximum throughput of 6 GB/s. That's in a laboratory. You won't see anything close to either of those in real life.

If you're connecting a SATA III device, use a SATA III port. If you're connecting a SATA II device, use a SATA II port.

 

A few questions come to mind: is the drive plugged into a eSATA port on the computer and its cable rated as SATA II? Or is it in an External USB drive case that is plugged into a USB 2.0 port or maybe a USB 3.0 port?

 

Sorry. It's a LaCie 3TB eSATA drive with a high speed 6Gb/s (as advertised, 80-wire I believe) cable plugged into my eSATA port. It's new and a replacement for a very ancient LaCie SATA II that died on me which worked fine for years using this cable. The BIOS is set to AHCI. The drive works as it should in Win7 but in my 2 X Win10 multi-boots the Post screen sometimes indicates SATA I when I'm booting between the 2 W10 OS's. It may be a false warning because Win 10 makes it impossible to really check the status of ATA channels.
Here's a pic of Device Manager with the drive highlighted and the relevant sections expanded.

 

I think I've solved it - sort of, and this is rather complicated.
I boot between systems a lot and when not in use the computer is powered completely off. The old external drive had a 3-way power switch: On, Auto and Off. Auto worked just fine for all systems and all scenarios.
The new drive only has On and Off and the literature says that On is supposed to be Auto, but I've watched the drive sometimes power itself back on long after I turned my machine off. So....bear with me.....
If I power the drive off when shutting down the PC or booting between systems then power the drive back on prior to the "Post" screen, all is well and it is detected every time as SATA II.
Perhaps a handshake issue in which case I will try another cable as you suggested, when I can get one.

Regarding the ATA speed, I realised that if I tell Device Manager to show hidden devices, then all the channels display and they all seem to be Ultra DMA Mode 5 or 6, so that tells me things are normal...as normal as things can be in Windows. ;-)