Hey Alex, let's tackle this for your game server setup. First, a quick hardware recap: your two X5650 CPUs deliver 12 physical cores (6 per socket) and 24 logical cores (via Hyper-Threading, 2 per physical core). Since game servers often rely heavily on single-core performance, we’ve got two tailored solutions to match your request:

Option 1: Disable Hyper-Threading to Use Only 12 Physical Cores #

If your game is primarily single-threaded, Hyper-Threading can sometimes hurt performance by sharing physical core resources (like L1/L2 cache). Disabling it will let you use just the 12 physical cores, which is ideal for single-core-focused workloads.

• Temporary fix (resets on reboot)：
  First, confirm your core topology with lscpu:

  lscpu | grep -E 'Core\(s\) per socket|Socket\(s\)|Thread\(s\) per core'
  

  You’ll see Thread(s) per core: 2 for your X5650s. Next, map logical cores to physical ones:

  for i in $(seq 0 23); do
    echo "Logical CPU $i → Physical Core $(cat /sys/devices/system/cpu/cpu$i/topology/core_id), Socket $(cat /sys/devices/system/cpu/cpu$i/topology/physical_package_id)"
  done
  

  Each physical core will have two logical cores (e.g., physical core 0 maps to logical 0 and 1). To disable the hyper-threaded logical cores, run:

  # Example: Disable every odd-numbered logical core (adjust if your mapping differs)
  for cpu in $(seq 1 2 23); do
    echo 0 > /sys/devices/system/cpu/cpu$cpu/online
  done
  

• Permanent fix (best practice)：
  The most reliable way is to disable Hyper-Threading directly in your server’s BIOS. Look for an option labeled "Hyper-Threading Technology" or similar, set it to Disabled, save changes, and reboot. Your system will now only recognize and use the 12 physical cores.

Option 2: Keep Hyper-Threading, but Bind Game Server to Physical Core Pairs #

If your game can leverage multi-threading, you can keep Hyper-Threading enabled but ensure your game server uses both logical cores tied to each physical core, while isolating these cores from other system processes.

• Step 1: Identify core pairs：
  Use the same mapping command from Option 1 to note which logical cores belong to each physical core. For example:

  Logical CPU 0 → Physical Core 0, Socket 0
  Logical CPU 1 → Physical Core 0, Socket 0
  Logical CPU 2 → Physical Core 1, Socket 0
  ...

• Step 2: Bind your game server to specific cores：
  Use the taskset command to launch your game server with core affinity. For single-core performance focus, bind to one logical core per physical core:

  # Bind to the first logical core of each physical core (12 total)
  taskset -c 0,2,4,6,8,10,12,14,16,18,20,22 ./your_game_server_executable
  

  If you want to use all 24 logical cores (utilizing Hyper-Threading), use:

  taskset -c 0-23 ./your_game_server_executable
  

  If you’re managing the game server via systemd, edit its service file (e.g., /etc/systemd/system/game-server.service) to set persistent core affinity:

  [Service]
  CPUAffinity=0,2,4,6,8,10,12,14,16,18,20,22
  ExecStart=/path/to/your_game_server_executable
  

  Then reload systemd and restart the service:

  systemctl daemon-reload
  systemctl restart game-server.service
  

Extra Optimizations for Game Servers #

To further boost performance for latency-sensitive games:

• Add kernel parameters to reduce scheduling overhead. Edit /etc/default/grub and update the GRUB_CMDLINE_LINUX line:

  GRUB_CMDLINE_LINUX="... nohz_full=0-11 rcu_nocbs=0-11"
  

  Replace 0-11 with the range of logical cores you’re using (e.g., 0-23 if using all cores). Then update GRUB:

  # Debian/Ubuntu
  update-grub
  # CentOS/RHEL
  grub2-mkconfig -o /boot/grub2/grub.cfg
  

• Disable unnecessary system services to free up CPU resources for your game server.

内容的提问来源于stack exchange，提问作者Alex Ulmer