E7400 or ram or GPU bottleneck

sherpa25

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May 24, 2012
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Thinking of upgrading an older PC, but not sure how to check which component is causing bottleneck. Currently have:
C2D e7400 in gigabyte ep45-ud3l board
Evga 650ti boost sc
4gb ram
5400rpm HDD

Max mem used I've seen in task mgr is only around 2.8gb, and that's with multiple Chrome tabs open.
How can I check/confirm which is/are causing a bottleneck in gaming performance? Thanks.