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PCI Subsystem Settings

PCI Subsystem Settings firmware setup page decoded from AMI HII/IFR resources.

Form ID: 0x286d
Records: 12
Parents: Advanced
Children: PCI Express Settings, PCI Express GEN 2 Settings, PCI Hot-Plug Settings
Path: Setup / Advanced / PCI Subsystem Settings / Setup / Advanced / Advanced / PCI Subsystem Settings

Record 1665

PCI Latency Timer

Firmware Value

Value to be programmed into PCI Latency Timer Register.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5eb
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcdc
Width: 1 byte(s)
Range: 32 to 248 step 0

Value	Label	Markers
`32`	32 PCI Bus Clocks	Standard defaultManufacturing default
`64`	64 PCI Bus Clocks
`96`	96 PCI Bus Clocks
`128`	128 PCI Bus Clocks
`160`	160 PCI Bus Clocks
`192`	192 PCI Bus Clocks
`224`	224 PCI Bus Clocks
`248`	248 PCI Bus Clocks

Visibility / conditions

{"condition_id": 717, "type": "SuppressIf", "offset": 388047, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 718, "type": "GrayOutIf", "offset": 388073, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1666

PCI-X Latency Timer

Firmware Value

Value to be programmed into PCI Latency Timer Register.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5ec
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xce0
Width: 1 byte(s)
Range: 32 to 248 step 0

Value	Label	Markers
`32`	32 PCI Bus Clocks
`64`	64 PCI Bus Clocks	Standard defaultManufacturing default
`96`	96 PCI Bus Clocks
`128`	128 PCI Bus Clocks
`160`	160 PCI Bus Clocks
`192`	192 PCI Bus Clocks
`224`	224 PCI Bus Clocks
`248`	248 PCI Bus Clocks

Visibility / conditions

{"condition_id": 719, "type": "SuppressIf", "offset": 388160, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 720, "type": "GrayOutIf", "offset": 388186, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1667

VGA Palette Snoop

Firmware Value

Enables or Disables VGA Palette Registers Snooping.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5ed
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcdd
Width: 1 byte(s)
Range: 0 to 1 step 0

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`0`	Disabled
`1`	Manufacturing	`0`	Disabled

Visibility / conditions

{"condition_id": 721, "type": "SuppressIf", "offset": 388273, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 722, "type": "GrayOutIf", "offset": 388299, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1668

PERR# Generation

Firmware Value

Enables or Disables PCI Device to Generate PERR#.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5ee
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcde
Width: 1 byte(s)
Range: 0 to 1 step 0

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`0`	Disabled
`1`	Manufacturing	`0`	Disabled

Visibility / conditions

{"condition_id": 723, "type": "SuppressIf", "offset": 388356, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 724, "type": "GrayOutIf", "offset": 388382, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1669

SERR# Generation

Firmware Value

Enables or Disables PCI Device to Generate SERR#.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5ef
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcdf
Width: 1 byte(s)
Range: 0 to 1 step 0

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`0`	Disabled
`1`	Manufacturing	`0`	Disabled

Visibility / conditions

{"condition_id": 725, "type": "SuppressIf", "offset": 388439, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 726, "type": "GrayOutIf", "offset": 388465, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1670

Above 4G Decoding

Observed

Enables or Disables 64bit capable Devices to be Decoded in Above 4G Address Space (Only if System Supports 64 bit PCI Decoding).

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5f0
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcd8
Width: 1 byte(s)
Range: 0 to 1 step 0
Observed value: 1
Observed label: Enabled
Observed date: 2026-10-14T03:10:49.661810+00:00
Observed source: selected-live-settings.json

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`1`	Enabled
`1`	Manufacturing	`1`	Enabled

Visibility / conditions

{"condition_id": 727, "type": "SuppressIf", "offset": 388522, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 728, "type": "GrayOutIf", "offset": 388548, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1671

Re-Size BAR Support

Observed

If system has Resizable BAR capable PCIe Devices, this option Enables or Disables Resizable BAR Support.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5f1
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcd9
Width: 1 byte(s)
Range: 0 to 1 step 0
Observed value: 1
Observed label: Enabled
Observed date: 2026-10-14T03:10:49.661810+00:00
Observed source: selected-live-settings.json

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`0`	Disabled
`1`	Manufacturing	`0`	Disabled

Visibility / conditions

{"condition_id": 729, "type": "GrayOutIf", "offset": 388605, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1672

BME DMA Mitigation

Firmware Value

Re-enable Bus Master Attribute disabled during Pci enumeration for PCI Bridges after SMM Locked

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5f2
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcdb
Width: 1 byte(s)
Range: 0 to 1 step 0

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`0`	Disabled
`1`	Manufacturing	`0`	Disabled

Visibility / conditions

{"condition_id": 730, "type": "SuppressIf", "offset": 388660, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 731, "type": "GrayOutIf", "offset": 388686, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1673

Don't Reset VC-TC Mapping

Firmware Value

If system has Vitrtual Channels, Software can reset Traffic Class mapping through Virtual Channels, to it's default state.

Firmware help text

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.

Form: PCI Subsystem Settings
Opcode: OneOf
Question ID: 0x5f3
VarStore: Setup
VarStore GUID: EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9
Offset: 0xcec
Width: 1 byte(s)
Range: 0 to 1 step 0

Value	Label	Markers
`0`	Disabled
`1`	Enabled

Default store records

Store ID	Store label	Value	Option label
`0`	Standard	`1`	Enabled
`1`	Manufacturing	`1`	Enabled

Visibility / conditions

{"condition_id": 732, "type": "SuppressIf", "offset": 388743, "expr": ["Uint64 Value: 0x0", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 733, "type": "GrayOutIf", "offset": 388769, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1674

PCI Express Settings

Menu Link

Change PCI Express Devices Settings.

Form: PCI Subsystem Settings
Opcode: Ref
Question ID: 0x5f4

Visibility / conditions

{"condition_id": 734, "type": "SuppressIf", "offset": 388835, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 735, "type": "SuppressIf", "offset": 388861, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 736, "type": "GrayOutIf", "offset": 388887, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1675

PCI Express GEN 2 Settings

Menu Link

Change PCI Express GEN Devices Settings.

Form: PCI Subsystem Settings
Opcode: Ref
Question ID: 0x5f5

Visibility / conditions

{"condition_id": 737, "type": "SuppressIf", "offset": 388925, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 738, "type": "SuppressIf", "offset": 388951, "expr": ["Uint64 Value: 0x1", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 739, "type": "GrayOutIf", "offset": 388977, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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Record 1676

PCI Hot-Plug Settings

Menu Link

Change PCI Express Hot-Plug and Standard HP Controller Settings.

Form: PCI Subsystem Settings
Opcode: Ref
Question ID: 0x5f6

Visibility / conditions

{"condition_id": 740, "type": "SuppressIf", "offset": 389015, "expr": ["Uint64 Value: 0x0", "Uint64 Value: 0x0", "Equal"]}
{"condition_id": 741, "type": "GrayOutIf", "offset": 389041, "expr": ["EqIdVal QuestionId: 0x1186, Value: 0x1"]}

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