Following are the details as per your questions
1) Server Load
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08:22:53 up 44 days, 13:31, 1 user, load average: 4.07, 5.09, 5.26
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/2 datacenter1.supp 08:17 0.00s 1.53s 0.00s w
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2) CPU and memory usage
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total used free shared buffers cached
Mem: 4040 3616 424 0 256 2809
-/+ buffers/cache: 550 3490
Swap: 8001 24 7976
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3) how many CPUs
3
EDIT: just took a snapshot here
http://www.thecodecage.com/forumz/server.png my server is like this all the time, this snapshot is AFTER enabling memcahce.