A question to the overclocking gurus on this web-site...

If I'm overclocking my Q9550 stock 2.83 GHz to 3.4 GHz (FSB going from 333 to 400), do I need a fan on my Thermalright HR-05 which sits on the Northbridge chip? I have an HR-05 IFX/SLI on the SB and an HR-05 IFX on the NB. I'd really like to do away with the fan, but do have one if it's needed. I'm on air cooling only, no water cooling at all. I have 120x38mm Panaflo NMB-MATs on the front and rear of the case (one each), and a 92x25mm on the Noctua U9B CPU.

Thanks all.