i5 2500k @ 3.3 ghz/GA-Z68X-UD3H-B3/8 gbs kingston Hyper x blu/nvidia 8800gt/ 1 tb hitatchi deskstar/asus 23" 2ms 1920x1080 led monitor
As previous users have already well explained what bottlenecking is. I noticed your build spec in your signature. It would seem your Graphics Card [8800GT] is what's bottlenecking your current system. It would be very helpful if you could tell us your PSU model so I can make a informed suggestion for which Graphics Card to consider if you need a new one. However, with what I already know I would highly recommend a 6870. Sure it's last generation but it offers much more performance for the same price than what's available in the current lineup and because it's older, its drivers are that much more mature.
Here is a 8800GT VS 6870 1GB Spec Sheet. The 6870 uses a mere 46Watts more than the 8800GT. http://www.gpureview.com/show_cards.php?card1=544&card2=635
****Note: If you have a 500W+ PSU, you should be fine, but do post your PSU model so we can make sure it can handle the extra load.