CrystalDisk: Transfer at SATA/150 but supported SATA/300

[cascais]

a. Recently swapped out a HGST HTS5410 for an EVO850 in my Satellite P50.
b. The Hitachi SATA/300 drive is now external, and CrystalDisk has it configured at SATA/150 no matter which USB2 or USB3 ports I connect it to.
c. CrystalDisk reports my WDPassport drive is current and supported at SATA/300..

 

[popatim]

In the bios, see if the sata port setting is on Performance. If its on battery it drops to the lower speed.
I'm not sure the p50 has that setting but the L50 did...

 

[cascais]

The problem with that suggestion is my SATA WD Passport when switched between the same USB ports shows Transfer 300 / Supported 300. This has to be a drive configuration issue.

 

[popatim]

The system moves at the speed of the slowest device in the chain, if the port drops to 150 speed then you get 150 speed no matter what you put in.
If the port stays at 300 or 600 and you install a 150 drive then you get 150 no matter what.

Doing some digging on toshiba support forums it seems that the performace mode has issues with SSD's in bios version 1.3 thru 1.7 and users downgraded to version 1.2 . Those posts are a few years old, can you check for a bios update on your exact model

 

[cascais]

Thank you for sticking with a novice!
Again, my drive states right on it: "SATA 3.0Gb/s" CrystalDisk acknowledges that but states that it is configured to 1.5Gb/s. Without a pin jumper I'm not sure how to re-configure the drive.

Re your request: Yes, Bios SATA Interface Setting: "Performance"

My Satellite PSPMHC-01M00P Bios is 1.7
Toshiba indicates that 1.9 is current for this computer.
However, when I extract the new Bios the closest reference is for PSPMHM", "PSPMHP", or "PSPMHU".
I'm a bit leery about installing it..