What's the stepping and week code on the chip? It's on the second line on the label, maybe something like AIUHB 0309, KIXIB 0335 or AQUCA 0345. Anyway, chips packaged after 0339 are locked; you can't unlock them so that the multi can be adjusted in the bios, nor can you pinmod them. If you join the third L5 bridge you turn the chip into a mobile, which allows you to adjust the multiplier from within your OS using a program.
Rich :¬)
Edit: a model 8 2400 is indeed a Tbred-B, so the stepping code won't start with AQ. Sorry, didn't spot that
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