Small performance gain?

I just finished benchmarking my cpu before and after overclock. Its a q9400, stock speed of 2.66, and after OC speed of 3.4ghz.
Is this a decent performance gain for the OC? It seemed kind of small considering I didn't even break 10,000 on 3D mark even after ocing the graphics card a little bit.

these are the results: http://service.futuremark.com/home [...] ultType=19

That's a gain of not quite 30% over stock. That's not so shabby.

If yu want more, it's time to get serious. What kind of motherboard? What's your CPU VID? What kind of cooler do you have? What kind of case.
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GA-EP35-DS3P
Q9550 OC'd to 3.6 GHz/TRUE/S-Flex SFF21-F
4 GB Crucial Ballistix
GTX260-216
WD 2.5 TB HD's total
Antec 900

Overclocking since 1978 - Z80 (TRS-80) from 1.77 MHz to 2.01 MHz