First of all, for CPU related questions, kindly post your questions in our PROCESSOR's community.
Now for a quick answer to your question, I suppose you are referring to Q9550
Well the CPU is originally 2.83GHz and should show the same frequency in the BIOS however you might want to update your BIOS to ensure if this is not a BIOS problem.
Secondly you also need to ensure if the CPU is actually Q9550 and that you have purchased it from an Intel reseller. If that is the case, kindly consult your reseller to file a complaint and request a replacement by showing the purchase receipt.
In case you have purchased a pre-assembled system from a local vendor, sometimes a vendor might tweak a system to show more frequency and sell you the wrong product which is a very rare case and if that is so, you can also file a complaint against your reseller with the local Intel office in your region. If any of the above is case, please let us know and for any further queries regarding the CPU, please post your questions in our PROCESSOR community as advised above and we will be glad to help.
Thank you, have a great day!
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