Blameless

Frankly, an OC like that is not going to happen on your motherboard.

There are only a handful of boards than can push a Yorkfield (45nm quad) to 485MHz FSB. To the best of my knowledge, the MSI 750i is not one of them.

Regardless, you would need some of the best air cooling out to deal with the heat at that voltage and speed.

Also, only the very best example of the Q9450s will clock that high on air. My better Xeon (best of two) X3350, could probably do it stably with a TRUE and a good fan, but past 3.7GHz the heat overwhelms my Xigmatek, and this cooler is significantly better than the stock cooler you've said you are using.

In short:

- I do not think such an OC is even possible on your MSI 750i motherboard.

- Even if it was, your cooling is woefully inadequate.

- A 50% OC on a quad is extremely ambitious for a first time OC.