DedicatedServer - Memory problem

[abhaykochar]

I hv Dedicated Server (RedHat) with Godaddy
My server run out of memory. I hv 1 GB of RAM, with P4
my php setting

memory_limit 16M,

but when i use top command to see apache process with memory it goes to RES: 70-90 M per user for few of them. So all memory out of 1GB get occupied by this only. so server stops responding.
How can i limit apache to use less memory per user.

when i used
"top -u apache" is gives me following o/p

top - 05:14:31 up 3:44, 1 user, load average: 0.09, 0.11, 0.08
Tasks: 153 total, 1 running, 152 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1032472k total, 1007176k used, 25296k free, 2108k buffers
Swap: 2096472k total, 2096472k used, 0k free, 48604k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2156 apache 20 0 155m 5796 4308 S 0 0.6 0:13.26 httpd
2157 apache 20 0 170m 5800 4320 S 0 0.6 0:13.72 httpd
3281 apache 20 0 171m 5512 4024 S 0 0.5 0:12.33 httpd
4257 apache 20 0 161m 5816 4020 S 0 0.6 0:07.18 httpd
4299 apache 20 0 157m 5816 4020 S 0 0.6 0:05.41 httpd
4315 apache 20 0 171m 5508 4020 S 0 0.5 0:09.45 httpd
4351 apache 20 0 172m 5764 4288 S 0 0.6 0:07.36 httpd
4385 apache 20 0 171m 5808 4020 S 0 0.6 0:07.76 httpd
4472 apache 20 0 157m 5808 4020 S 0 0.6 0:03.89 httpd
4489 apache 20 0 171m 5792 4024 S 0 0.6 0:04.75 httpd
4524 apache 20 0 171m 5856 4024 S 0 0.6 0:03.96 httpd
4541 apache 20 0 171m 5520 4032 S 0 0.5 0:05.30 httpd
4545 apache 20 0 171m 5804 4024 S 0 0.6 0:05.68 httpd
4546 apache 20 0 171m 5828 4012 S 0 0.6 0:03.07 httpd
4590 apache 20 0 171m 5724 3948 S 0 0.6 0:04.60 httpd
4605 apache 20 0 170m 5760 3944 S 0 0.6 0:03.24 httpd
4609 apache 20 0 164m 5816 4020 S 0 0.6 0:03.93 httpd
4643 apache 20 0 156m 5940 4336 S 0 0.6 0:06.26 httpd
4666 apache 20 0 171m 5820 4020 S 0 0.6 0:04.07 httpd
5377 apache 20 0 152m 5820 4212 S 0 0.6 0:04.84 httpd
5517 apache 20 0 170m 5768 3944 S 0 0.6 0:03.08 httpd
5538 apache 20 0 171m 11m 4044 S 0 1.1 0:07.32 httpd
5553 apache 20 0 157m 5844 4020 S 0 0.6 0:04.14 httpd
5611 apache 20 0 171m 72m 4020 S 0 7.1 0:05.34 httpd
5694 apache 20 0 171m 91m 4084 S 0 9.1 0:06.29 httpd
5702 apache 20 0 171m 83m 3952 S 0 8.3 0:04.12 httpd
5744 apache 20 0 171m 91m 4088 S 0 9.1 0:04.58 httpd
5750 apache 20 0 171m 89m 4024 S 0 8.9 0:03.84 httpd
5752 apache 20 0 46468 12m 3804 S 0 1.3 0:04.37 httpd
5788 apache 20 0 46468 13m 3984 S 0 1.3 0:03.46 httpd
5811 apache 20 0 171m 92m 4028 S 0 9.1 0:03.06 httpd
5821 apache 20 0 171m 92m 4012 S 0 9.1 0:02.71 httpd
5833 apache 20 0 171m 91m 3748 S 0 9.0 0:02.64 httpd
5854 apache 20 0 46536 12m 3792 S 0 1.3 0:01.51 httpd
5873 apache 20 0 157m 83m 3948 S 0 8.2 0:02.65 httpd
5889 apache 20 0 171m 91m 3956 S 0 9.1 0:04.22 httpd
5895 apache 20 0 45884 12m 3728 S 0 1.2 0:00.93 httpd
5900 apache 20 0 45620 11m 3724 S 0 1.2 0:01.06 httpd
5905 apache 20 0 40244 4112 1860 S 0 0.4 0:00.07 httpd