After adding APC
5000 fetches, 5 max parallel, 5.1645e+07 bytes, in 66.1261 seconds
10329 mean bytes/connection
75.6131 fetches/sec, 781008 bytes/sec
msecs/connect: 0.21676 mean, 0.939 max, 0.174 min
msecs/first-response: 64.1843 mean, 1074.19 max, 12.774 min
HTTP response codes:
  code 200 -- 5000
Using apc_load_constants()
<?php
if(!apc_load_constants('bench_constants')) {
    $constants = array("MYMOD_VERSION"=>"1.234-alpha");
    for($i=0; $i<1000; $i++) {
        $constants[sprintf("MY_CONST_%04d", $i)] = $i;
    }
    apc_define_constants('bench_constants', $constants);
}
?>
With apc_load_constants()
5000 fetches, 5 max parallel, 5.1645e+07 bytes, in 46.0241 seconds
10329 mean bytes/connection
108.639 fetches/sec, 1.12213e+06 bytes/sec
msecs/connect: 0.225471 mean, 0.938 max, 0.174 min
msecs/first-response: 44.1477 mean, 805.834 max, 8.793 min
HTTP response codes:
  code 200 -- 5000