All you need (possible explanation for heavy movement feel)

[agendarsky]

First of all: R.I.P AM5 users , usb controller mode 2.0 is forced to go HiSpeed and you cant change it, its not present in IFR data, i've checked almost every board possible and they just did it , probably in agesa.
I returned my 7800x3d and went intel 14700k and iam very satisfied.

Usb controller mode 2.0 - --> Fullspeed 12mbps <-- makes mouse perfectly snappy especially horizontal movement, u can make perfect non-jittery 90'' angle turn with this setting. Along side with this setting , im using XHCI hand off disabled and EHCI hand off enabled.

The second one everyone can try and is giving that "adderal movement feel and responsiveness" is : Setup Question = Don't Reset VC-TC Mapping
Help String = If system has Vitrtual Channels, Software can reset Traffic Class mapping through Virtual Channels, to it's default state. Setting this option to Enabled will not modify VC Resources.
Token =73B // Do NOT change this line
Offset =1159
Width =01
BIOS Default =[01]Enabled
Options =*[00]Disabled // Move "*" to the desired Option
[01]Enabled

.... use Disabled. There is not much articles about this setting so i asked GPT and here its answer according to his data knowledge:
This setting affects PCIe Virtual Channels (VC) and Traffic Class (TC) mapping. When enabled (Enabled), the BIOS prevents software (such as drivers or the OS) from resetting the default Traffic Class-to-Virtual Channel mapping. When disabled (Disabled), software is allowed to reset and modify this mapping as it sees fit.
What are Virtual Channels (VC) and Traffic Class (TC)?
Virtual Channels (VC) are logical pathways within a PCIe link that help manage data flow by providing Quality of Service (QoS). Think of them as separate "lanes" for different types of data, ensuring that critical operations receive priority.
Traffic Class (TC) is how the OS and drivers categorize different types of data transfers. Each TC can be mapped to a specific Virtual Channel.
How does this affect stuttering and input lag?
When "Don't Reset VC-TC Mapping" is set to Disabled, software (such as Windows or GPU drivers) can modify the default TC-to-VC mapping, which can lead to:
Dynamic priority adjustments – The OS and drivers attempt to optimize data flow.
Unpredictable packet handling – If the system remaps data improperly, it can introduce latency and microstuttering.When "Don't Reset VC-TC Mapping" is set to Enabled (the default BIOS setting), it ensures a consistent mapping, resulting in:
✔ Predictable data flow – No sudden remapping by the software.
✔ Smoother frame pacing – Frame-to-frame latency remains stable.
✔ Faster system responsiveness – Because there are no unexpected priority shifts at the PCIe level.
.... But somehow going disabled is way to go.

If someone is interested , this is my scewin dump on Z790 Aorus Elite AX-W https://drive.google.com/file/d/1dcgVqw ... sp=sharing
ps: im not using any regedit tweaks, i have stock windows nvidia drivers and iam using balanced power plan.

[agendarsky]

Claude answer: VC (Virtual Channels) and TC (Traffic Classes) are mechanisms used in PCI Express (PCIe) for data flow management:

Virtual Channels (VC):


These are independent virtual "paths" within a single physical PCIe connection
They allow simultaneous transmission of different types of data through the same physical connection
Help with prioritization of different types of transfers


Traffic Classes (TC):


Define priorities for different types of data transfers
Higher TCs have higher priority in transmission
Are typically mapped to specific Virtual Channels

When the "Don't Reset VC-TC Mapping" setting is disabled:

The system uses default TC to VC mapping
Can lead to simpler and more direct data processing
Reduces overhead associated with managing multiple virtual channels

Why the game runs faster with the setting disabled:

Reduced latency:


Fewer layers of data processing
Simpler data flow routing


More direct data path:


No complex mapping between TC and VC
Faster processing of peripheral inputs


Lower system overhead:


Fewer resources needed for virtual channel management
More efficient use of the PCIe bus

[n1zoo]

Mine was already set on disabled, sadly, no adderal movement feel and responsiveness..
Btw, tried Enabled - nothing changed.

[Hyote]

The VC-TC Mapping setting is really good, thanks for sharing.

[wados]

can i enable Don't Reset VC-TC Mapping feature on amd b550 motherboard with scewin or its only for intel based feature?

[ablemor]

Video? Still works?

[JimCarry]

First of all: R.I.P AM5 users , usb controller mode 2.0 is forced to go HiSpeed and you cant change it, its not present in IFR data, i've checked almost every board possible and they just did it , probably in agesa.
I returned my 7800x3d and went intel 14700k and iam very satisfied.

Usb controller mode 2.0 - --> Fullspeed 12mbps <-- makes mouse perfectly snappy especially horizontal movement, u can make perfect non-jittery 90'' angle turn with this setting. Along side with this setting , im using XHCI hand off disabled and EHCI hand off enabled.

The second one everyone can try and is giving that "adderal movement feel and responsiveness" is : Setup Question = Don't Reset VC-TC Mapping
Help String = If system has Vitrtual Channels, Software can reset Traffic Class mapping through Virtual Channels, to it's default state. Setting this option to Enabled will not modify VC Resources.
Token =73B // Do NOT change this line
Offset =1159
Width =01
BIOS Default =[01]Enabled
Options =*[00]Disabled // Move "*" to the desired Option
[01]Enabled

.... use Disabled. There is not much articles about this setting so i asked GPT and here its answer according to his data knowledge:
This setting affects PCIe Virtual Channels (VC) and Traffic Class (TC) mapping. When enabled (Enabled), the BIOS prevents software (such as drivers or the OS) from resetting the default Traffic Class-to-Virtual Channel mapping. When disabled (Disabled), software is allowed to reset and modify this mapping as it sees fit.
What are Virtual Channels (VC) and Traffic Class (TC)?
Virtual Channels (VC) are logical pathways within a PCIe link that help manage data flow by providing Quality of Service (QoS). Think of them as separate "lanes" for different types of data, ensuring that critical operations receive priority.
Traffic Class (TC) is how the OS and drivers categorize different types of data transfers. Each TC can be mapped to a specific Virtual Channel.
How does this affect stuttering and input lag?
When "Don't Reset VC-TC Mapping" is set to Disabled, software (such as Windows or GPU drivers) can modify the default TC-to-VC mapping, which can lead to:
Dynamic priority adjustments – The OS and drivers attempt to optimize data flow.
Unpredictable packet handling – If the system remaps data improperly, it can introduce latency and microstuttering.When "Don't Reset VC-TC Mapping" is set to Enabled (the default BIOS setting), it ensures a consistent mapping, resulting in:
✔ Predictable data flow – No sudden remapping by the software.
✔ Smoother frame pacing – Frame-to-frame latency remains stable.
✔ Faster system responsiveness – Because there are no unexpected priority shifts at the PCIe level.
.... But somehow going disabled is way to go.

If someone is interested , this is my scewin dump on Z790 Aorus Elite AX-W https://drive.google.com/file/d/1dcgVqw ... sp=sharing
ps: im not using any regedit tweaks, i have stock windows nvidia drivers and iam using balanced power plan.

Thanks for sharing, as you say people with amd 5 mb dont have this and its for intel only,i search in my scewin export file but i dont have none of the two options you provide,i was wondering is there is something close for amd ?also i can upload my "dump" from the two scewin versions i have but on the my motherboard it dumps very small part of the options,for example on my old asus mb you disable HPET via scewin,but if you go in bios with f8 you cant even see the option,now scewin exports file options but id does not show it.

[[email protected]]

Even for Intel and YOUR scewin there is no "Setup Question = Don't Reset VC-TC Mapping" option

[JimCarry]

Even for Intel and YOUR scewin there is no "Setup Question = Don't Reset VC-TC Mapping" option

ok so if not working for intel or amd then what is op using then ?

[[email protected]]

Even for Intel and YOUR scewin there is no "Setup Question = Don't Reset VC-TC Mapping" option

ok so if not working for intel or amd then what is op using then ?

I think it was just a "joke"..... :/