• Dell Latitude 5591 ¹⁾
• BIOS 1.26 ²⁾
• IFR Values

• Enable/Disable Audio DSP

• Audio DSP is unusable on Linux with Intel MEI disabled

• Default: Disabled
• Ideal: Enabled

setup_var_cv Setup 0xF48 0x1 0x1

• Specifies DSP enabled system compliance:
• 1. Non-UAA (IntelSST driver support only)
• 2. UAA (HD Audio Inbox or IntelSST driver support)

• Audio DSP is unusable on Linux with Intel MEI disabled

• Default: 1 (UAA)
• Ideal: 0 (Non-UAA)

setup_var_cv Setup 0xF49 0x1 0x0

• Enable/Disable Overclocking Lock (BIT 20) in FLEX_RATIO(194) MSR

• Default: Enabled
• Ideal: Disabled

setup_var_cv Setup 0x659 0x1 0x0

• Configure MSR 0xE2[15], CFG Lock bit

• Default: Enabled
• Ideal: Disabled

setup_var_cv Setup 0x5BD 0x1 0x0

• Select DVMT 5.0 Pre-Allocated (Fixed) Graphics Memory size used by the Internal Graphics Device

• Default: Unknown
• Ideal: 64M

setup_var_cv Setup 0x8D2 0x1 0x2

• Select DVMT5.0 Total Graphic Memory size used by the Internal Graphics Device

• Default: Unknown
• Ideal: MAX

setup_var_cv Setup 0x8D3 0x1 0x3

• Enable/Disable above 4GB MemoryMappedIO BIOS assignment
• This is enabled automatically when Aperture Size is set to 2048MB

• Default: Disabled
• Ideal: Enabled

setup_var_cv Setup 0x8D7 0x1 0x1

• Select the Aperture Size

• Default: 256MB
• Ideal: 2048MB

setup_var_cv Setup 0x821 0x1 0xF

• Enable PCH to aggressively enter link power state

• Default: Enabled
• Ideal: Disabled

setup_var_cv Setup 0xA7E 0x1 0x0

• Enable/Disable CSM Support

• Default: Unknown
• Ideal: Disabled

setup_var_cv Setup 0x11A6 0x1 0x0

• Default: COM1
• Ideal: Disabled

setup_var_cv Setup 0x13DD 0x1 0x0

• Default: Unknown
• Ideal: 1200Mhz

setup_var_cv Setup 0x82B 0x1 0x18

• Default: Unknown
• Ideal: 1GHz

setup_var_cv Setup 0x66F 0x1 0x1

• Maximum Value of TOLUD
• Dynamic assignment would adjust TOLUD automatically based on largest MMIO length of installed graphic controller

• Default: Unknown
• Ideal: 3.5 GB

setup_var_cv Setup 0x90E 0x1 0xB

setup_var_cv Setup 0x10C1 0x1 0x0
setup_var_cv Setup 0x10BF 0x1 0x0
setup_var_cv Setup 0x147E 0x1 0x1
setup_var_cv Setup 0x7B2 0x1 0x1
setup_var_cv Setup 0xA07 0x1 0x0
setup_var_cv Setup 0x1177 0x1 0x0