BIOS Setup¶

MS-S1 MAX specific BIOS configuration for optimal performance with AMD APU workloads.

Accessing BIOS¶

Power on the system and press the appropriate key during POST:

Method	Key
Primary	Del
Alternative	F2

Timing

Press the key repeatedly as soon as you see the Minisforum logo. USB keyboards may have a slight delay.

Memory Settings¶

Memory configuration is critical for APU performance since the integrated GPU shares system RAM.

XMP/DOCP Profile¶

Enable memory profiles to run DDR5 at rated speeds:

Setting	Location	Recommended
XMP/DOCP	Advanced > Memory	Enabled
Memory Profile	Advanced > Memory	Profile 1 (highest rated)

The MS-S1 MAX ships with DDR5-5600 memory. Without XMP/DOCP enabled, memory may default to JEDEC speeds (4800 MHz), significantly reducing performance.

Why memory speed matters:

Token generation is memory-bandwidth bound
Higher frequency = more bandwidth = faster inference
DDR5-5600 vs DDR5-4800 is ~17% bandwidth difference

UMA Frame Buffer Size¶

The UMA (Unified Memory Architecture) Frame Buffer allocates a portion of system RAM as dedicated video memory for the integrated GPU:

Setting	Location	Recommended
UMA Frame Buffer	Advanced > Graphics	Auto or 16GB
VRAM Size	(same setting, different name)	Auto or 16GB

Setting options explained:

Value	Use Case
Auto	Dynamic allocation, usually sufficient
512MB-4GB	Desktop/server without GPU workloads
8GB-16GB	GPU compute, AI inference
32GB+	Heavy 3D rendering (rarely needed for LLMs)

LLM Inference

For llama.cpp and similar tools, the UMA setting is less critical than total system RAM. The inference engines manage memory directly. However, ROCm applications may benefit from larger UMA allocation.

Memory Interleaving¶

Ensure memory is running in dual-channel mode:

Setting	Location	Recommended
Channel Interleaving	Advanced > Memory	Auto or Enabled
Bank Interleaving	Advanced > Memory	Auto or Enabled

Verify dual-channel operation from Linux:

sudo dmidecode -t memory | grep -E "Number Of Devices|Locator"

Both DIMM slots should be populated for dual-channel bandwidth.

AMD APU Settings¶

IOMMU (AMD-Vi)¶

Required for virtualization and GPU passthrough:

Setting	Location	Recommended
IOMMU	Advanced > AMD CBS	Enabled
ACS Enable	Advanced > AMD CBS	Enabled (if available)

Verify from Linux:

dmesg | grep -i iommu

Above 4G Decoding¶

Allows PCIe devices to use memory addresses above 4GB:

Setting	Location	Recommended
Above 4G Decoding	Advanced > PCI	Enabled
Re-Size BAR	Advanced > PCI	Enabled

Re-Size BAR (Resizable BAR) enables the CPU to access the full GPU memory range, beneficial for some workloads.

iGPU Configuration¶

Setting	Location	Recommended
Primary Display	Advanced > Graphics	Auto or IGFX
iGPU Multi-Monitor	Advanced > Graphics	Enabled (if using displays)

For headless server operation, these settings have minimal impact. The iGPU remains available for compute regardless.

CPU Settings¶

Precision Boost Overdrive (PBO)¶

PBO allows the CPU to boost beyond stock limits when thermal and power headroom exists:

Setting	Location	Recommended
PBO	Advanced > AMD CBS > SMU	Advanced or Enabled
PBO Limits	Advanced > AMD CBS > SMU	Auto

For 24/7 server operation, consider:

Conservative: PBO Disabled - Stable, predictable power
Balanced: PBO Auto - Reasonable boost, default behavior
Performance: PBO Advanced - Maximum performance, higher power/heat

SMT (Simultaneous Multi-Threading)¶

Setting	Location	Recommended
SMT	Advanced > AMD CBS	Enabled

SMT provides 32 threads from 16 cores. Disable only if specific workloads perform better with SMT off (rare for server workloads).

cTDP / TDP Settings¶

If available, configure power limits:

Setting	Description
cTDP	Configurable TDP limit
PPT	Package Power Tracking limit
TDC	Thermal Design Current limit
EDC	Electrical Design Current limit

For 24/7 operation, stock settings provide a good balance. Increase only if cooling is adequate.

Power and Thermal Settings¶

Power Profile¶

Setting	Location	Recommended
Power Profile	Advanced > Power	Balanced or Performance
Package Power Limit	Advanced > Power	Auto

For server use:

Balanced - Good performance, reasonable power
Performance - Maximum speed, higher power draw
Low Power - Reduced performance, quieter operation

AC Power Recovery¶

Important for unattended operation:

Setting	Location	Recommended
AC Power Loss	Advanced > Power	Power On
Power On After Power Fail	(same)	Always On

This ensures the server restarts automatically after power outages.

Fan Control¶

Setting	Location	Recommended
Fan Mode	Hardware Monitor or Advanced > Thermal	Auto or Silent
Fan Curve	(if available)	Custom

For 24/7 operation, prioritize cooling over noise. The system should maintain safe temperatures under sustained load.

Virtualization Settings¶

For KVM/QEMU virtual machines:

Setting	Location	Recommended
SVM	Advanced > CPU	Enabled
IOMMU	Advanced > AMD CBS	Enabled
NX Mode	Advanced > CPU	Enabled
SME	Advanced > AMD CBS	Enabled (optional)

SVM (Secure Virtual Machine) is AMD's virtualization technology, equivalent to Intel VT-x.

Boot Settings¶

Setting	Location	Recommended
Boot Mode	Boot	UEFI
Secure Boot	Boot > Security	Enabled (optional)
Fast Boot	Boot	Disabled
Boot Order	Boot	NVMe first

Secure Boot

Secure Boot can be enabled with Ubuntu but may complicate kernel module loading for out-of-tree drivers. Disable if troubleshooting driver issues.

Settings Summary¶

Quick reference for AI/server workloads:

Category	Setting	Value
Memory	XMP/DOCP	Enabled
Memory	UMA Frame Buffer	Auto or 16GB
AMD	IOMMU	Enabled
AMD	Above 4G Decoding	Enabled
AMD	Re-Size BAR	Enabled
CPU	PBO	Auto or Enabled
CPU	SMT	Enabled
Power	AC Power Loss	Power On
Boot	Boot Mode	UEFI

Saving and Exit¶

After making changes:

Press F10 or navigate to Exit > Save Changes and Reset
Confirm saving changes
System will reboot with new settings

Verifying Settings from Linux¶

After booting Ubuntu, verify BIOS settings took effect:

# Check memory speed
sudo dmidecode -t memory | grep Speed

# Check IOMMU
dmesg | grep -i -e DMAR -e IOMMU

# Check Resizable BAR
lspci -vvv | grep -i "resize"

# Check virtualization
grep -E 'svm|vmx' /proc/cpuinfo

# Check PBO/boost status
cat /sys/devices/system/cpu/cpu0/cpufreq/boost