Hardware and performance

We tested Moodle for 50 concurrent users using JMeter with following details

System hardware : Intel Core 2 Duo T8100 @ 2.10 GHz, 2.09GHz
2 GB RAM

Test Case : 50 users concurrently accessed login page, entered credentials and then logged out. Requests were distributed over 1 second (i.e. 1 second ramp).
JMeter test case file is attached here for further reference.

Result :
----------------------------Activity -------------------------------90% line(ms) ------------error %
1) home page view before login -------------------------7873-------------------------0
2) login page view --------------------------------------------1393------------------------0
3) login info submission -------------------------------------26985---------------------- 0
4) home page view after login ----------------------------28334---------------------- 0
5) logout--------------------------------------------------------- 696------------------------- 0
6) home page view after logout --------------------------23413---------------------- 0

During the test case execution average CPU consumption by Apache was 95 % .
But RAM was consumed about 700 MB
Is that obvious ? Or CPU consuption by Apache is it too high?

Additional Info:
eAccelerator is used with following settings in php.ini

extension=eaccelerator.dll
eaccelerator.shm_size = "64"
eaccelerator.cache_dir = "C:\xampp\tmp"
eaccelerator.enable = "1"
eaccelerator.optimizer = "1"
eaccelerator.debug = "0"
eaccelerator.check_mtime = "1"
eaccelerator.filter = ""
eaccelerator.shm_max = "10"
eaccelerator.shm_ttl = "0"
eaccelerator.shm_prune_period = "0"
eaccelerator.shm_Xonly= "0"
eaccelerator.compress = "1"
eaccelerator.compress_level = "9"
eaccelerator.keys = "shm_and_disk"
eaccelerator.sessions = "shm_and_disk"
eaccelerator.content = "shm_and_disk"
eaccelerator.admin.name=
eaccelerator.admin.password =

Please let me know if any other information is required.