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TensorRigs

BIOS/UEFI Optimization

Why BIOS Settings Matter

Section titled “Why BIOS Settings Matter”

Your BIOS/UEFI firmware controls fundamental hardware behavior. Incorrect settings can:

  • Reduce GPU performance by 10-20%
  • Cause system instability during long training runs
  • Prevent GPUs from being detected
  • Limit PCIe bandwidth

Time investment: 15-20 minutes Performance gain: Up to 20% in some cases

Accessing BIOS/UEFI

Section titled “Accessing BIOS/UEFI”

On boot, press the designated key repeatedly:

  • Most systems: Delete or F2
  • ASUS: Delete or F2
  • MSI: Delete
  • Gigabyte: Delete
  • ASRock: Delete or F2
  • Dell/HP workstations: F2 or F10

Essential Settings for ML Workloads

Section titled “Essential Settings for ML Workloads”

1. PCIe Configuration

Section titled “1. PCIe Configuration”

Why it matters: GPUs need maximum PCIe bandwidth for optimal performance.

Navigation: Advanced → PCIe/PCI Configuration

Settings:

PCIe Speed: Gen 4 (or highest available)
Above 4G Decoding: Enabled
Re-Size BAR Support: Enabled (if available)

Location: Usually under “Advanced” → “PCI Subsystem Settings”

2. Power Management

Section titled “2. Power Management”

Goal: Prevent power-saving features from throttling during training.

Settings to change:

Power State: High Performance
C-States: Disabled
CPU Enhanced Halt (C1E): Disabled
Intel SpeedStep / AMD Cool'n'Quiet: Disabled

Why disable power saving?

  • Prevents CPU throttling during training
  • Ensures consistent performance
  • Eliminates wake-up latency

3. Multi-GPU Systems

Section titled “3. Multi-GPU Systems”

If you have 2+ GPUs, these settings are critical:

IOMMU / VT-d: Enabled (for PCIe passthrough capabilities)
Bifurcation: Check manual for your board
PCIe Link Speed: Gen 4 (Gen 3 minimum)

PCIe Lane Distribution: For optimal multi-GPU:

  • 2 GPUs: x16/x16 or x16/x8
  • 3 GPUs: x16/x8/x8
  • 4 GPUs: x8/x8/x8/x8

4. Memory Configuration (XMP/DOCP)

Section titled “4. Memory Configuration (XMP/DOCP)”

Enable XMP/DOCP profile:

Memory Profile: XMP / D.O.C.P / A-XMP

What this does:

  • Runs RAM at rated speed (3200MHz, 3600MHz, etc.)
  • Without this, RAM runs at base JEDEC speed (2133MHz)
  • Significantly improves data loading performance

5. Virtualization

Section titled “5. Virtualization”

Enable if using Docker or VMs:

Intel VT-x: Enabled
Intel VT-d: Enabled

Location: Advanced → CPU Configuration

Why enable this?

  • Required for Docker containers (common in ML workflows)
  • Needed for running VMs
  • Better PCIe device management

6. Boot Options

Section titled “6. Boot Options”

Optimize boot time:

Fast Boot: Enabled
Boot Logo Display: Disabled
Bootup NumLock State: On (preference)
Full Screen Logo: Disabled

7. Security Settings

Section titled “7. Security Settings”

For easier development:

Secure Boot: Disabled

Why?

  • Some Linux distros and CUDA drivers conflict with Secure Boot
  • Can re-enable later if needed

Settings to Leave as Default

Section titled “Settings to Leave as Default”

Don’t change these unless you know what you’re doing:

  • CPU Core Voltage (unless overclocking)
  • DRAM Voltage (XMP handles this)
  • Fan curves (configure in OS instead)
  • Boot priority (set after OS install)

BIOS Settings Checklist

Section titled “BIOS Settings Checklist”

Print or save this checklist:

  • PCIe Speed set to Gen 4 (or highest)
  • Above 4G Decoding: Enabled
  • Re-Size BAR: Enabled
  • Power Management: High Performance
  • C-States: Disabled
  • XMP/DOCP Profile: Enabled
  • Virtualization (VT-x/SVM): Enabled
  • VT-d/IOMMU: Enabled
  • Secure Boot: Disabled
  • Fast Boot: Enabled
  • Settings saved and system rebooted

Verification After Boot

Section titled “Verification After Boot”

Once in your OS, verify settings took effect:

# Check PCIe generation
lspci -vv | grep -i "lnkcap\|lnksta"

# Should show "Speed 16GT/s" for Gen 4

# Check if all GPUs detected
nvidia-smi

# Verify XMP/DOCP worked
sudo dmidecode -t memory | grep Speed

Troubleshooting

Section titled “Troubleshooting”

GPU Not Detected

Section titled “GPU Not Detected”
  1. Re-seat the GPU physically
  2. Try a different PCIe slot
  3. Update BIOS to latest version
  4. Check if Above 4G Decoding is enabled

System Won’t Boot After Changes

Section titled “System Won’t Boot After Changes”
  1. Clear CMOS (consult motherboard manual)
  2. Remove one setting at a time
  3. Likely culprit: XMP profile incompatibility

Lower Than Expected PCIe Speed

Section titled “Lower Than Expected PCIe Speed”
  1. Check GPU is in primary x16 slot
  2. Verify PCIe generation in BIOS
  3. Some boards drop to Gen 3 with multi-GPU

Manufacturer-Specific Guides

Section titled “Manufacturer-Specific Guides”

ASUS Boards

Section titled “ASUS Boards”
  • Press F7 for Advanced Mode
  • Look under “Advanced” and “AI Tweaker” tabs

MSI Boards

Section titled “MSI Boards”
  • Press F7 for detailed view
  • Settings → Advanced tab

Gigabyte Boards

Section titled “Gigabyte Boards”
  • Press Ctrl+F1 for advanced options (on some models)
  • Check “Tweaker” and “Peripherals” tabs

ASRock Boards

Section titled “ASRock Boards”
  • Advanced mode enabled by default
  • Check “OC Tweaker” for performance settings

Next Steps

Section titled “Next Steps”

After optimizing BIOS:

  1. Save settings and exit (F10 usually)
  2. Proceed to OS Installation
  3. Later: Monitor system health