Upgrading CPU in a HP z2g5

[Emilesfl]

I'm trying to upgrade the CPU in my HP Z2g5 from an i5 10505 to an i7 10700k and I'm getting an unsupported cou error when I boot up. I've tried everything from a previous post that had the same issue. I have the 700 watt PSU installed, the 125 watt cooler, updated bios, reset CMOS. I looked in the Bios settings for a power management setting like previous post suggested and don't see that. Not sure what else to do. Please help!

[NonSequitur777]

@Emilesfl,

Welcome to our HP Community forum!

Thank you for your detailed post -you're clearly doing all the right things in terms of troubleshooting!

You're correct that the HP Z2 Tower G5 Workstation platform supports 10th Gen Intel Core processors. However, there's a lesser-known but important nuance when it comes to CPU compatibility: not all motherboards in this series are created equal...

Key Discovery: Motherboard SSID Differences:

The Z2 G5 Workstation was shipped with two motherboard variants:

• SSID: 8750 – supports higher TDP CPUs such as the i7-10700K/F and i9-10900K/F (125-watt TDPs).

• SSID: 8751 – does not support higher TDP CPUs; limited to 65-watt CPUs.

What gave it away for me is that an i5-10505 is specifically a 65-watt TDP locked CPU, something you don't see very often.

You can check your motherboard’s SSID by opening System Information (type msinfo32 in the Run dialog), or by looking in the BIOS under system details.

Why You’re Seeing the "Unsupported CPU" Error:

Even though your system can run a 10th Gen i5-10505 just fine, the i7-10700K is a 125-watt unlocked processor, and HP has blocked support for these CPUs on SSID: 8751 motherboards -probably due to VRM/power delivery limitations and long-term reliability concerns.

Recommended Path Forward:

If your board is SSID: 8751 (as I suspect), I’d recommend:

• Swapping the i7-10700K for a non-K version like the i7-10700 (65-watt TDP, still 8 cores & 16 threads)

• Alternatively, an i9-10900 (also 65-watt) is supported on many G5 configurations

These processors offer excellent performance and should boot sans any issues whatsoever.

---

Let me know if you'd like help finding a compatible CPU or if you'd like to explore other upgrade paths. You're almost there!

Kind Regards,

NonSequitur777

[Emilesfl]

Hi, thank you for the info! You are correct! I have the 8751 motherboard. That's really annoying that they list several CPUs on their compatibility page in the manual but don't specify the exact motherboard or I may have missed something. I guess I'll try to sell the i7 10700k I just got on eBay and look into those other options. I'm happy with my current setup. I mostly use this computer for gaming and light office use at home. I put an AMD RX6800xt in it and it runs Fortnite at 200 fps.

[NonSequitur777]

@Emilesfl,

Outstanding: to be able to run Fortnite at 200 fps is not too shabby!

Kind Regards,

NonSequitur777