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I have a Lenovo Thinkcentre Model 8811DEU. It has 4 DDR memory slots and 'Core 2 Duo 6400' cpu. The clock rate is 2.16Ghz.

I would like to upgrade the CPU to quad core and a faster clock. We tried a Q9550S Core 2 Quad cpu. But, the machine never shows anything on the screen. I suspect it is not getting thru the BIOS startup. No beep sequence is emitted.

I chose the Q9550S because it had the same 65W rating as the existing 6400 cpu and should not cause any heat dissipation issues. Although, the existing cpu is not even getting the heatsink warm.

My questions are this: Is the Lenovo BIOS specifically designed to prevent this kind of upgrade? Should it have worked? What are my options? Is it time to purchase a new machine?

Thanks in advance, Jim

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up vote 3 down vote accepted

The official specs for this show it only available with an E6400, E6500, or E6600. The BIOS probably isn't locked, per se, but it's very likely only built to work with a narrow subset of microcode. The two chips you tried aren't even the same generation chip (the one in there is a 65nm Conroe, the Q9550S is a 45nm Yorkfield) so it's not surprising that the newer chip wouldn't work. The only thing you can really do is to make sure you're running the newest BIOS. Beyond that, you might try another Conroe chip (but there are no quad cores available) but just be aware that even that isn't a guarantee it'll work unless it's an E6500 or E6600, which are a marginal upgrade here IMO.

The short version: you can't just expect to pop any chip with compatible pinouts in an OEM motherboard and expect it to work, sadly.

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Nice summarised. – Sathya Feb 23 '11 at 19:04
Thank you. Sadly, this is the answer that I expected. Also, I agree that the E6400 to E6600 upgrade is so insigificant that it would be a complete waste of time/money. – Jim Reineri Feb 23 '11 at 20:16
@Jim - Yeah, sorry I can't give you better news. It might be worth your while digging through Google or asking on the Lenovo forums if anybody's had any luck with other chips. The M55p was a great machine at the time. :/ – Shinrai Feb 23 '11 at 20:19

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