USB - Partial or Full Initialization in BIOS?

I Googled "Partial or Full Initialization in BIOS" to see the difference, but only found threads where setting to one or the other was suggested to cure various PC issues...

I had a bit of a scare today when my PC got stuck on Windows Resume Loader after a hibernation resume failure. No mouse or keyboard input worked and it took me a while to remember (to my great relief!) that the PC has a PS2 mouse port, and that I have a spare PS2 keyboard... once I plugged it in, I could of course select to abandon the resume and reboot afresh..

In the interim though, I did go into the BIOS and changed USB Initialization from 'Partial' to 'Full' (I read that the USB function can get turned off in this kind of case, so I assumed, albeit half-heartedly, that the failure had changed the setting). But now I wonder whether it was set to Partial by default. I've also read that having Fast Boot on means that the USB setting is at Partial.

So, what are the practical consequences of having either one setting or the other? And should I go back to Partial Initialization for some reason? Having the USB set to Full seems the general recommendation, but..

Hope some techie in this area can explain the details of this! Thanks,

Martin

(I'm going to be using a PS2 keyboard full time now - and I have disabled hibernation as well - saving 12GBs of space into the bargain).

BIOS is the fist software loaded and it defines how the hardware should work, regardless of the OS.
Modern BIOS, specially UEFI like yours, has some "BIOS drivers" that are temporary loaded till the OS takes control and load their own drivers.
On boot, those "BIOS drivers" can take some time to be loaded and then replaced by OS drivers. Fast Boot or Partial Initialization, doesn't load "BIOS drivers" to save time but the hardware won't work till the OS is loaded.

I found out that the overall saved time is little so I have set "BIOS drivers" to Full Initialization (Fast boot=Off).

I haven't noticed any difference (yet) when I boot, so I'll leave it on Full. I just wondered exactly how the PC responded differently at boot with the two settings. Does full just mean more 'BIOS drivers' are loaded for USB?? I'd have thought it was all or nothing, but clealry not.

Thanks.

It isn't only the USB drivers, but depends on the MB BIOS. You have USB, LAN etc.
I would say you have 3 modes.
- No drivers
- Partial (USB, maybe LAN)
- All drivers

martinlest said:

...the PC has a PS2 mouse port, and that I have a spare PS2 keyboard...I'm going to be using a PS2 keyboard full time now.

You're very fortunate to have both a PS/2 port and a PS/2 keyboard. PS/2 is the most reliable type of keyboard and mouse - they never fail, as long as you are powered down when you connect or disconnect them.

I have had USB fail twice in my life. In both cases, the computer had PS/2 ports, and I had an available PS/2 keyboard and mouse. It was therefore very simple in both cases to troubleshoot and fix the USB problem.

It would be good if vendors would always include PS/2 ports, even if they don't include a PS/2 keyboard or mouse, because in an emergency, PS/2 can be a lifesaver. Or, even better, if someone would sell a PCI Express PS/2 card (with true PS/2, not USB-to-PS/2). I have a PCI PS/2 card, but it is really hard these days to find a computer with PCI slots.

Yes, I was lucky with the PS2 - it's a relatively new PC, so it wasn't a given that when I checked on the back that a PS2 port would be there. I use a PS2 keyboard on my second PC, so all was well.

Over the years, I have had more problems with USB than with any other single aspect of my computers - BSODs and freeze ups, which turned out to be due to USB-related issues (drivers, controllers and so forth). I wish they'd (whoever 'they' might be! Intel??) get it right rather than putting so much effort into getting faster and faster (in theory at least) read/write speeds! I have a new USB-C drive, but I am certainly not going to invest in a new card for it. The PC on which I use the PS2 keyboard and mouse only has USB2.0 and often transfers just as fast as with USB3.0 on the other machine, especially with Windows 7, which seems to have big problems with USB3.0.