Hot ‘n’ Noisy fixes some rare timing issues caused by AMD’s Cool ‘n’ Quiet and Intel’s SpeedStep features.

Hot ‘n’ Noisy remedies erratic frame rates with:

  • Unreal Gold
  • Unreal Tournament ’99
  • Grand Theft Auto San Andreas
  • Grand Theft Auto Vice City — additionally fixes non-functional menus, unresponsive keyboard/mouse in-game, and inconsistent vehicle spawning distances
  • Deus Ex
  • Crazy Taxi 3

It is likely to work with many other games with similar issues, especially those based on the Unreal or Grand Theft Auto 3 engines. The list may include:

  • Unreal Tournament 2
  • Unreal Tournament 2003 (2004 does not have the problem)
  • Grand Theft Auto 3

Cool ‘n’ Quiet and SpeedStep are superb technologies to cool your PC’s processor by lowering the CPU frequency upon light loads.  The only issue I find with them is that some older games rely on the CPU speed to remain constant, and adjust their rate to compensate, with the assumption that the CPU can’t possibly have ‘dynamic frequency scaling’.  Turning off Cool ‘n’ Quiet or SpeedStep is simply not a practical solution.

The problem is when some games speed up, they use more CPU time, and then the CPU’s clock is sped up to compensate for the new demand.  The game eventually notices the speed increase, and slows the engine down. This has the effect of less CPU time overall being used, so the CPU clock is slowed back down again.  The repeats over and over, and to the end-user it looks like the game is often going too fast or too slow.

Hot ‘n’ Noisy keeps the CPU speed at its highest whilst a game runs.  It mostly keeps the CPU busy with NOPs (which mean ‘no operation’), so the CPU doesn’t heat very much.  It’s fairly clever in that it runs at Low priority, on CPU 0, whilst running the game on CPU 0 at the same time, and it quits when it sees the game has quit.  This effectively simulates the environment of an old PC, but with a fast CPU.

This program runs as a host for any other program.  There are 3 possible ways to run it.  Either:

  • Simply run Hot ‘n’ Noisy, and then specify the executable of the other program when it asks you.  Or…
  • Copy and/or modify the shortcut for the game, and put Hot ‘n’ Noisy’s path ahead of the game’s command-line.  All extra parameters are passed on.  Or…
  • Drag an executable file on top of Hot ‘n’ Noisy’s icon. (120KiB)