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2 Intern

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27 Posts

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February 19th, 2026 10:45

Precision 7865 CPU Upgrade (Threadripper Pro)

Has anyone upgraded the CPU in a 7865 or 7875 ?

I have a 7865 fitted with a 5945, have purchased a 5995, but the PC wont boot with it installed

This points to 2 scenarios -

1 - A faulty CPU

2 - The CPU being BIOS locked to another OEM / Vendor

If the CPU is unlocked (and working) should it be as simple as just dropping it in ?

Thanks

10 Wizard

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February 19th, 2026 17:32

These are not "retail and/or aftermarket" motherboards.

 

It's been my experience that usually, Dell-OEM motherboard only contain the necessary BIOS-firmware micro-code to boot-and-run the list of main-processors that originally shipped with it when new from the factory. Their PDF or marketing literature should have a list of CPU's.

2 Intern

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27 Posts

February 19th, 2026 20:49

@Tesla1856​ Thanks for your reply, and yes I agree, and this is what i have followed

All I am doing is upgrading from the entry level CPU (5945wx) to the top of the range (5995wx), this option that was available from Dell

10 Wizard

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February 19th, 2026 20:55

@m74brown​ ,

Interesting.

 

So, I have also seen reports of newer revision motherboards. And while there is only one BIOS-Firmware available, they are hardware-different (obviously) with some slightly different BIOS options available. You can therefore extrapolate that maybe only they support the newer processors.

 

Are you at least running the latest BIOS-version?

(edited)

2 Intern

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27 Posts

February 19th, 2026 21:14

@Tesla1856​ Yes, latest BIOS. And what makes me suspect the CPU in faulty or locked, is that my system was supplied by a Dell Partner as refurbished, the services tag of the system shows it left dell with a 5995wx CPU in it (providing the chassis and motherboard are the same) which I believe they are

10 Wizard

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February 20th, 2026 00:11

@m74brown​ ,

 

@Tesla1856

1. Yes, latest BIOS.

 

2. my system was supplied by a Dell Partner as refurbished, 

1. Cool, good.

 

2. The plot thickens ...

2 Intern

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27 Posts

February 26th, 2026 15:27

@Tesla1856 ok , original CPU was definitely faulty, as it displayed random led codes and would not post

replacement cpu, still doesn't post it just sits in a power on/off loop

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