Dear all, I have a simple test code in different OS ,but it give me a different result. the code as follows: <?php $n= 50000; for($i=0;$i<$n;$i++) { $data[]=array("",$i,$i/1000); echo $i," ",$data[$i][1],"<br>"; } echo "count:",count($data); ?> OS1: Red Hat Enterprise Linux Server release 5.1 Linux 2.6.18-53.el5xen i686 i686 i386 GNU/Linux test result: the result is correct,it can display 50000 data and count:50000. OS2: CentOS release 5.4 Linux 2.6.18-164.el5 x86_64 x86_64 x86_64 GNU/Linux test result: the result is wrong,it can only display 31148 data and it can not display count value. I'm not sure the result relate to array capacity in different OS. Please give me some tips,thanks in advance. good luck, Yang Fei 2010-7-20