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- HP Z2 Mini G9 Motherboard Part Numbers & Differences?

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11-18-2023 11:34 AM - edited 11-18-2023 11:37 AM
Hi, I am brand new to HP and I would simply like some information.
I see that there are two potential motherboards for use in this HP Z2 Mini G9 system.
One part number is M85205-601 and the other is M85205-602.
On the HP Parts Surfer website, you can actually look up both of these parts -- however -601 has the photo taken upside down, so you can't actually see if there are any noticeable differences between that and -602 (I have to wonder if this was done deliberately...?)
I would like to know what the actual differences are, and also which specific part my own Z2 Mini G9 has in it.
I tried asking an HP support rep and they told me the two parts are "functionally equivalent and have zero actual hardware differences" -- but that doesn't make any sense to me, what would be the need for two distinct part numbers then?
Clearly there have to be SOME differences?
Or maybe there is something I am not understanding here?
That's entirely possible! But it seems to me that if there were in fact no actual differences, then there would be only one part number and not two..I mean, right?
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11-18-2023 01:57 PM - edited 11-18-2023 02:05 PM
The conspiracy has gotten worse, oh my! See below... one of your motherboards is for sale on eBay and behold:
There is even an AS# and a SP#, and even a different "HP SPARE" number that is different from the SP#. And barcodes with certain meanings...
I'd not be too concerned. On most HP parts there is an AS# (Assembly Part Number) and a SP# (Spares Part Number)... two numbers for the exact same part. And, if HP chooses to use a whole set of different components on a motherboard one or both of those numbers might change... say a different vendor for all the capacitors, so they can keep track.
And there even is a thing called "branding" which is a HP factory firmware flash to the motherboard that has to do with what the computer is licensed for. Linux vs Windows, old Windows such as W7Pro64 vs new Windows such as W8, W10. Pro, Pro vs Home W10... you get the point. They have to keep these things organized to properly pay companies like Microsoft and Intel.
In the past there have been version 1 and version 2 motherboards for the Zx00 and Zx20 workstations, which allowed different processors to be used. There is no such issue for the Zx40 generation of workstations. HP always was clear about major revisions, issuing a customer advisory document, and it was easy to look at the BIOS boot block date or the bar code label's printed part numbers on the motherboard and tell what was what. There's been a lot of minor motherboard PCB revisions and minor part updates that don't warrant such an advisory. There are even "microcode" updates inside some BIOS updates that can allow use of a new processor that HP found worth certifying as supported for use on a particular workstation.
Welcome, by the way.
11-18-2023 01:57 PM - edited 11-18-2023 02:05 PM
The conspiracy has gotten worse, oh my! See below... one of your motherboards is for sale on eBay and behold:
There is even an AS# and a SP#, and even a different "HP SPARE" number that is different from the SP#. And barcodes with certain meanings...
I'd not be too concerned. On most HP parts there is an AS# (Assembly Part Number) and a SP# (Spares Part Number)... two numbers for the exact same part. And, if HP chooses to use a whole set of different components on a motherboard one or both of those numbers might change... say a different vendor for all the capacitors, so they can keep track.
And there even is a thing called "branding" which is a HP factory firmware flash to the motherboard that has to do with what the computer is licensed for. Linux vs Windows, old Windows such as W7Pro64 vs new Windows such as W8, W10. Pro, Pro vs Home W10... you get the point. They have to keep these things organized to properly pay companies like Microsoft and Intel.
In the past there have been version 1 and version 2 motherboards for the Zx00 and Zx20 workstations, which allowed different processors to be used. There is no such issue for the Zx40 generation of workstations. HP always was clear about major revisions, issuing a customer advisory document, and it was easy to look at the BIOS boot block date or the bar code label's printed part numbers on the motherboard and tell what was what. There's been a lot of minor motherboard PCB revisions and minor part updates that don't warrant such an advisory. There are even "microcode" updates inside some BIOS updates that can allow use of a new processor that HP found worth certifying as supported for use on a particular workstation.
Welcome, by the way.
11-18-2023 04:33 PM
Ah! So that makes sense. Like if they changed caps or some other supply chain component vendor stuff, but it truly is exactly the same , just from a different vendor. IDK why the support rep didn't just explain it like that 😄
I am ultimately concerned about being locked out from upgrading the cpu etc on my own, though.
What IS potentially an issue is that this thing ships with two different heatsinks / blowers, depending on what CPU it was configured with from the factory.
The non K series (65W) cpus ship with an aluminum heatsink and a different blower, where as the K series CPUs ship with a bulkier 125W copper heatsink and a different blower -- My guess is the blower is basically the same but with a different pinout so the mobo knows which one is plugged in.
Anyway, mine came with a 65W i5-12500 CPU...which means I got the crappier aluminum 65W heatsink.
Seems like a total bean counter move on HP's part -- and incredibly ironic as Linus from LTT did a video about this computer and his findings were that the more expensive bulkier 125W copper heatsink was **still inadequate** to cool an i9, lol. So I wonder if it will even make a difference in the end anyway!
I would love if someone has experience with these computers could let me know what the best CPU would be to run in them. No point in getting an expensive i9 if it's going to thermal throttle or power throttle. That's another thing, the PSU is only 280W.
11-18-2023 06:28 PM - edited 11-18-2023 06:31 PM
Many HP workstations have mainstream and higher performance configurations. In fact, the heatsink/fan for those two are termed Mainstream and Performance by HP. I've posted before on how the motherboard knows the difference... usually that has to do with presence of a ground jumper from the PWM fan's plug native ground to another added socket built in to the fan's plug... often native ground to socket 5, and thus the motherboard knows a Performance heatsink/fan is attached.
As these computers age a bit Performance heatsinks/fans will come onto the recycle market. The faster processors drop down in price too. In the HP workstation world I live in there is crossover of some parts from servers to the high end HP workstations. Servers tend to be recycled sooner than good quality PCs, so I get sooner access to processors/memory that were used both by servers and workstations. Supply can be high from the server end; price can be low from the supply end.
Edit: If you wanted big you should have bought a bigger box.
11-23-2023 07:15 AM
Has anyone noticed noisy coil whine off their Z2 G9s?
Mine screams away, its really really distracting and annoying, once you hear it on every move of your mouse, ever scroll of a window, its impossible to ignore.
I wonder if a later revision system board would fix this issue?
11-23-2023 09:55 AM - edited 11-23-2023 10:00 AM
Mine is dead silent. I actually put it in “rack mode” just to make sure it’s cooling itself appropriately heh.
Coil whine usually comes from GPU or from the power brick (in my experience anyway, yes I know it can come from anywhere). Try taking the dGPU out first and see if you can isolate it.
You’ll have to get access to a different power brick to see if the original brick you have is what is causing it though.
11-23-2023 10:04 AM
That reinforces my view that its faulty then.
Screams away when moving mouse over lists in excel or emails etc.
Touch the mouse and show the W11 start menu? lol. screams away, I can hear every movement on screen.
Its not the GPU, that's basically off most of the time, I changed the C-state or whatever its called in the Z2 BIOS and it made it much better, so it's 100% CPU Coil whine, but it was silent to begin with and got progressively worse, to the point now where I have to use headphones just so I can concentrate and not hear it.
Other than that, it IS a silent system in terms of fans etc.
I am desperately hoping that the lower clock speed of the 13th Gen CPU will help along with a system board replacement.
The rev1 powerbrick actually had a fault on it too, but that was replaced and it no longer made a noise. You again could hear caps whining or coils inside the PSU especially when the system was off, you could hear the PSU cycling on a 1hz wave in standby!
A replacement PSU which was rev3 sorted that though, and is silent.
Makes me wonder if a rev3 systemboard with these Z2 might well be the answer.