Performance & Stability Optimizations

Performance & Stability Optimizations
This page documents the specific kernel and hardware tweaks applied to Terra (Ryzen 5950X / Ubuntu 24.04) to optimize for container performance, storage throughput, and long-term stability.
🛡️ Stability & Power Management (The "Golden Config")
Typical Current Idle (UEFI)
Setting: Advanced > AMD CBS > CPU Common > Power Supply Idle Control = "Typical Current Idle"
Benefit: Prevents the Ryzen "Sleep of Death" where the PSU cuts power during deep C-state transitions. Essential for 24/7 server stability on X570 boards.
Processor C-State Limit (Kernel)
Driver: 
processor.max_cstate=1
Benefit: Software-side enforcement of the Idle fix. Limits the CPU to C1 (Halt/Idle) instead of deeper sleep states (C6), preventing interrupt processing delays and hardware hangs.
Configuration: Added to 
GRUB_CMDLINE_LINUX_DEFAULT in 
/etc/default/grub.
65W Eco Mode (Manual PBO)
Settings: PPT: 88, TDC: 60, EDC: 90
Benefit: Drastically reduces thermals (peak temps dropped from ~90°C to 58°C) without significant impact on multi-core performance. Ideal for 4U rackmount chassis airflow.
Configuration: UEFI > Precision Boost Overdrive > Manual.
⚡ CPU & Power Performance
AMD P-State (Active Mode)
Driver: 
amd_pstate=active (EPP - Energy Performance Preference)
Benefit: Allows the kernel to communicate directly with the Zen 3 power management controller. Enables a wider frequency range (550MHz - 5000MHz).
IRQ Balancing
Service: 
irqbalance (Installed/Enabled)
Benefit: Distributes hardware interrupts (HBA, NVMe, NIC) across all threads, preventing Core 0 bottlenecks.
🧠 Memory Tuning
Speed & Stability
Configuration: Currently hard-coded to 2133MHz at AUTO voltage.
Note: Troubleshooting in Feb 2026 confirmed that 3000MHz at 1.35V caused instantaneous reboots. Stability requires sticking to JEDEC defaults for now.
Static Hugepages
Setting: 
hugepages=2048 (Reserving 4GB total as 2MB pages)
Benefit: Reduces TLB misses for memory-heavy apps like Minecraft and Postgres.
💾 I/O & Network Tuning (sysctl)
ZFS Write Buffering
Settings: 
vm.dirty_background_bytes = 268435456, 
vm.dirty_bytes = 1073741824
Benefit: Prevents the kernel from buffering too much data in RAM before flushing to ZFS, eliminating system-wide UI/process stutter.
Fluent-bit Batching (ClickHouse)
Setting: 
Flush 60 in 
fluent-bit.conf
Benefit: Reduced ClickHouse CPU usage from 80% spikes to <5% by reducing transaction frequency and optimizing ZFS write contiguousness.
🎮 GPU Optimization (Quadro P2200)
Persistence Mode
Command: 
sudo nvidia-smi -pm 1
Benefit: Eliminates the 2-second initialization delay for AI inference and transcoding containers.