i9 detected as i7

[fmc5046]

Hey all,

I recently built a computer with an i9 7900x processor, with an MSI x299M motherboard, the computer boots up no problem and I was able to install an OS no problem.

The CPU is detected incorrectly as an i7 7800x in the BIOS , the CPU speed shows correctly at 3.5GHz, but only shows 6 cores as opposed to the expected 10.

I updated the BIOS and reset the CPU multiple times but no luck. I've checked that the motherboard supports this CPU and have seen others online use this motherboard with the same BIOS SW. Any ideas what could cause the misdection? I went so far as to recheck on the CPU itself that it is in-fact an i9 to see if the wrong CPU was shipped by mistake. My guess is its something in the BIOS settings but I can't figure out what it could be.

UPDATE: I removed the CPU again to check and added the images. From my untrained eye everything seemed to look correct. I didn't see any signs of the lid being removed and re-glued. Good catch on the processors running at different speeds (3.5 Ghz vs 3.3 Ghz). Is it possible that the wrong lid was put on the CPU at the factory or something?

Thanks in advance.
Fred

 

[bignastyid]

What is printed on the top of the cpu?

 

[COLGeek]

Are you 100% certain you have the right CPU model? From where did you purchase it?

 

[fmc5046]

Yea so it had the right processor number printed on it, i9-7900x. I took off the heat sink and scrapped back the thermal paste to double check

 

[1LiquidPC]

Do you have pics of CPU, packaging, ect? Sounds like you may have gotten a counterfeit.

 

[antonio.parrot]

Hey all,

I recently built a computer with an i9 7900x processor, with an MSI x299M motherboard, the computer boots up no problem and I was able to install an OS no problem.

The CPU is detected incorrectly as an i7 7800x in the BIOS , the CPU speed shows correctly at 3.5GHz, but only shows 6 cores as opposed to the expected 10.

I updated the BIOS and reset the CPU multiple times but no luck. I've checked that the motherboard supports this CPU and have seen others online use this motherboard with the same BIOS SW. Any ideas what could cause the misdection? I went so far as to recheck on the CPU itself that it is in-fact an i9 to see if the wrong CPU was shipped by mistake. My guess is its something in the BIOS settings but I can't figure out what it could be.

Thanks in advance.
Fred

3,5 GHz is the clock base of i7 7800x. Clock base of i9 7900x is 3,3 GHz.

 

[COLGeek]

Where did you buy the CPU from?

 

[bignastyid]

Possible some bought both, swapped the lids and sent it back. Contact the store you bought it from.

 

[mdd1963]

a few folks are delidding cpus, mailing cheaper one (with original heatspreader) back to distributor in apparent unopened status, and pocketing the new CPUs, seller thinks it is unopened, and sells it....

This has happened before, not sure how they are keeping the box in 'like new' condition enough to escape detection of tampering....

Fraud much more likely than Intel accidentally using the wrong heat spreader, sorry to say...

 

[Pinhedd]

+1 on this being a lid swap. The exact model of the CPU is encoded in the CPU itself and is retrieved using the CPUID instruction

 

[1LiquidPC]

Another vote for lid swap, good chance it was intentional. These CPUs can be delidded and then a relid performed. Likely someone sent back a 7800X CPU with 7900X lid, which looks like what you may have purchased. They kept the 7900x w/ 7800x lid for themselves. The chances of the motherboard, especially latest UEFI, not correctly identifying CPU has to be nearly impossible these days.