Steampowered has news of the latest steam updates, this time lot of source engine optimisations, mainly to do with cutting out as much hitching and pausing as possible while playing Half-Life 2.

# Improved the performance of writing out save games. This will reduce the pause when you pass over an autosave trigger in Half-Life 2, or when you press the quicksave button
# Improved the performance of writing out the thumbnail image for save games. This will also reduce the pause when passing over an autosave trigger or pressing the quicksave button
# Increased cache memory usage for machines that have greater than 512MB of physical memory. This will reduce hitching due to cache thrashing.
# Optimized the sound cache manager, which will reduce hitching as a result of sound cache thrashing
# Minor optimization to the world renderer and world collision
# Minor optimization to the way that asynchronous sound files are loaded
# Optimized the way that sounds were loaded that are trigged by acting sequences
# Optimization to reduced the number of times model sequences are iterated on per frame
# Fixed rcon packet bug that was accepting negative packet lengths
# Fixed rcon server failing on server restart

There are also some other minor updates to Half-life2 itself, the source linux server and Condition Zero.