XHCI hand-off

[alfik]

XHCI hand-off is enabled by default in my BIOS (ASRock B650M-HDV/M.2). After disabling it, I noticed that my mouse movement feels different.

After researching the topic I found a lot of old and conflicting info. Even mobo manufacturers can't seem to make up their minds, it's disabled by default on some boards and enabled on others.

My understanding is that it exists to make USB 3 work on old systems (Windows 7), and has no effect in Windows 10 and 11. It boggles my mind that nobody is talking about it because it definitely alters how mouse movement feels.

Is it XHCI hand-off enabled or disabled that has less input latency?

[RealNC]

This is one of those settings where all information I can find about it appears to be wrong. Apparently, "it needs to be enabled" for USB 3 to work if the OS supports USB 3. For older operating systems that don't support USB 3, "it needs to be disabled" so the ports will still be usable but run at USB 2 speeds.

Well, this was never true for me. Whether I disable or enable it, my USB 3 ports work at USB 3 speeds (tested with external USB SSD) in both Windows 10 and Linux. It's a confusing setting for sure.

[alfik]

Yes, same here. USB 3 works as intended whether XHCI hand-off is enabled or disabled. I suppose it would only matter in Windows 7 and older systems. But even in Windows 11 it still changes how the XHCI controller is handled and has an impact on mouse movement.

Makes it even more confusing that the setting exists and is enabled by default on modern AM5 motherboards. No sane person uses Windows 7 with a Ryzen 7xxx.

[AyayronPlays]

My understanding as far as i know (not an expert) is that it simply hands off the usb to the OS as opposed to being handled by the bios

Whether that's true or not, i have no idea

[MatrixQW]

This is one of those settings where all information I can find about it appears to be wrong. Apparently, "it needs to be enabled" for USB 3 to work if the OS supports USB 3. For older operating systems that don't support USB 3, "it needs to be disabled" so the ports will still be usable but run at USB 2 speeds.

Well, this was never true for me. Whether I disable or enable it, my USB 3 ports work at USB 3 speeds (tested with external USB SSD) in both Windows 10 and Linux. It's a confusing setting for sure.

BIOS: "This is a workaround for OSes without XHCI hand-off support. The XHCI ownership change should be claimed by XHCI driver"
The text can be confusing and there is alot of contradictory information on internet but as I understand it, enabled is the workaround and should be disabled for W10 because the OS supports hand-off and that's why it works with it enabled/disabled.
Enabled = BIOS
Disabled = OS (if supported)

Is it XHCI hand-off enabled or disabled that has less input latency?

According to what I said and if it is correct, disabled should give less latency since you are not forcing something that the OS already supports.

[Hyote]

I'm starting to be confused about why all the recent posts are about settings that were explored a long time ago. You can find 10 different forum posts about them. Disable XHCI-handoff, disable as many USB ports as you can, just look up any guide like the one from r0ach. Even it looks crazy, it isn't. Start looking at the real culprit which is Windows. Strip the entire OS (no apps, Defender), disable services, disable HPET, good power plan, timer res, important GPU settings like disabling HDCP support, regedit settings, change priority of csrss to realtime, things like dwm, dllhost, fontdrvhost, sppsvc to idle. Assign affinities to your USB, GPU, Ethernet and also audiodg, csrss, dwm, fontdrvhost, lsass, SetTimerResolution, ShellExperienceHost, sihost, and multiple instances of svchost if you can. Many of these can destabilize your system so you need to set them to the right cores.

[Slender]

This is one of those settings where all information I can find about it appears to be wrong. Apparently, "it needs to be enabled" for USB 3 to work if the OS supports USB 3. For older operating systems that don't support USB 3, "it needs to be disabled" so the ports will still be usable but run at USB 2 speeds.

Well, this was never true for me. Whether I disable or enable it, my USB 3 ports work at USB 3 speeds (tested with external USB SSD) in both Windows 10 and Linux. It's a confusing setting for sure.

for z390 that work correctly - usb 3.0 devices lowering to usb 2.1

[JimCarry]

So in the end disabled or enabled?

[MatrixQW]

So in the end disabled or enabled?

I can't be sure but it seems to me that it will depend on how the setting is implement on each board because of Slender and RealNC contrary statements.
Some boards clearly say that enabled means it's for an OS that doesn't have hand-off support so it works as a compatibility setting.
In this case it should be disabled for W10/11 but even if it's enabled, devices will still work properly at the corresponding speed.
However, for Slender's board it has an effect.

So, disable it and if your devices still work at proper speed you might as well leave it disabled. This is my take.
You can use 'usb device viewer' or whatever app to see the connection speed of the devices.

[JimCarry]

So in the end disabled or enabled?

I can't be sure but it seems to me that it will depend on how the setting is implement on each board because of Slender and RealNC contrary statements.
Some boards clearly say that enabled means it's for an OS that doesn't have hand-off support so it works as a compatibility setting.
In this case it should be disabled for W10/11 but even if it's enabled, devices will still work properly at the corresponding speed.
However, for Slender's board it has an effect.

So, disable it and if your devices still work at proper speed you might as well leave it disabled. This is my take.
You can use 'usb device viewer' or whatever app to see the connection speed of the devices.

i think you mean this program but i dont know where to look right now is disabled in bios?