PHP 4.4.2:
Initialize 1 million objects: 1192.52 ms
Initialize 1 million arrays: 735.15ms
Fetch object: 2.34ms
Fetch array: 0.81ms
Make object with 1,000 properties: 3ms
Make array with 1,000 keys: 2.51ms
Foreach through 1,000 object properties: 3.78ms
Foreach through 1,000 array keys: 2.6ms
PHP 5.1.2:
Initialize 1 million objects: 811.72 ms
Initialize 1 million arrays: 281.83ms
Fetch object: 0.94ms
Fetch array: 0.72ms
Make object with 1,000 properties: 1.77ms
Make array with 1,000 keys: 1.38ms
Foreach through 1,000 object properties: 0.98ms
Foreach through 1,000 array keys: 1.21ms