Processor AMD Phenom II X4 820 2.8 GHz on HP dc5850 MT with Microsoft Windows 11 24H2 : NOT OK !!!

[Papy_Mougeot]

Hello,

This little thread just to say that on my very old HP dc5850 MT (bios 3.14 Rev. A, 16 GB RAM) I was able to install the (very good !) processor AMD Phenom II X4 955, 3.2 GHz, socket AM2+/AM3, TDP 95W, part number HDX955WFK4DGM, without any problem, and which has the SSE4a extension that integrates, among other things, the POPCNT instruction that will be mandatory for Microsoft Windows 11 24H2; so no blocking to come.

[EDIT]

For Microsoft Windows 11 24H2 (and following versions), processor (AMD or INTEL !) must have complete SSE4.2 instruction set, and not only POPCNT instruction and also not only SSE4a set for AMD processors !!! Otherwise the computer will not boot !!!

https://www.cpu-world.com/CPUs/K10/AMD-Phenom%20II%20X4%20955%20-%20HDX955WFK4DGM.html

Note that this processor does not appear in HP's official documentation for this computer.

So I can still save my antique by using the RUFUS utility !

I used before an AMD Athlon X2 5600+ 2.9 GHz Brisbane (ADO5600IAA5DO), without SSE4a extension.

Tchao. 

Alain

[EDIT]

I should add that to install Microsoft Windows 11 24H2 (and following) on an INTEL (or AMD) processor, the processor requires to support the complete SSE4.2 extension set (otherwise you risk a complete boot block).

All this, of course, in addition to the initial hardware requirements for Windows 11 (processor, TPM 2.0, secure boot, UEFI, memory...) which can be bypassed using the RUFUS utility, if Microsoft doesn't add to them in the meantime. 

[Papy_Mougeot · Accepted solution]

...And for purists, you can also install the AMD Phenom II X4 820 2.8 GHz processor on HP dc5850 MT, which is exactly the same series as the Phenom II X4 805 2.5 GHz (or 810 2.6 GHz) indicated in the official HP documentation : TDP 95W, stepping RB-C2, CPUID/Ext F.4.2/10.4, 4 Mb cache L3, with SSE4A instruction. OK with Windows 11 and RUFUS...