I have the feeling that from what I have been able to read, the Z400 is probably my best bet as a cheap replacement in case it breaks. The only con that I am able to see when compared against the ud5-x58a is:

1. Only Sata2, no Sata 3
2. No usb 3.0, requires special pci board for those
3. No overclocking (not a real problem)
4. Much less ports in the back. But still have some essentials
5. Much worse integrated sound board.

Except overclocking, you can get around the problems with some pci boards.

1. SATA3 was a joke on most X58 boards, unless you're looking for specific late boards like Gigabyte G1 Sniper, ASUS Rampage III Black, etc.
2. USB3.0, usually, was also powered from one or two PCIe 1x lanes (depending on amount of USB 3.0 ports), so about 200mb/s speed, shared between two ports. You can get modern external USB3.0+SATA3 controller which is faster anyway.
4. It has 6 USB ports, which most X58 boards had anyway. Other ports were mostly just clutter, like useless Firewire, eSATA, clear CMOS button or additional LAN.

Also Z400 does not match standard ATX mounting holes 100%, so you might need some slight modding for 2-3 non-standard mounting holes in your case.

The Serpent Rider wrote on 2023-06-05, 02:10:

1. SATA3 was a joke on most X58 boards, unless you're looking for specific late boards like Gigabyte G1 Sniper, ASUS Rampage III […]
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1. SATA3 was a joke on most X58 boards, unless you're looking for specific late boards like Gigabyte G1 Sniper, ASUS Rampage III Black, etc.
2. USB3.0, usually, was also powered from one or two PCIe 1x lanes (depending on amount of USB 3.0 ports), so about 200mb/s speed, shared between two ports. You can get modern external USB3.0+SATA3 controller which is faster anyway.
4. It has 6 USB ports, which most X58 boards had anyway. Other ports were mostly just clutter, like useless Firewire, eSATA, clear CMOS button or additional LAN.

Also Z400 does not match standard ATX mounting holes 100%, so you might need some slight modding for 2-3 non-standard mounting holes in your case.

That post kind of discouraged me to get one, what a huge amount of work! I think I will pray for the best so my motherboard does not break then!

The Serpent Rider wrote on 2023-06-05, 02:10:

Also Z400 does not match standard ATX mounting holes 100%, so you might need some slight modding for 2-3 non-standard mounting holes in your case.

HP seems to like doing the mounting hole thing.
At some point I was gifted a very small HP PC which came in a tiny (and for my tastes too noisy) ATX-alike case. I wanted to transplant it to a new case (a 'new' case made by Antec which at least had better cooling options than the old case) when I found out the mounting holes didn't match up. Of the 4 holes, only one had the correct spot with the other 3 being in different spots. I still managed to botch the HP motherboard into the Antec case by using some of that electrical isolation tape for the 3 not matching standoffs, a piece of plastic stuck in the top of the case using double sided sticky tape to press the board against the tray and a block of glued plywood sawed to the millimeter on which the motherboard rests.
I'm actually typing this message from that system 🤣.

The PSU seemed to have the correct color coding for standard ATX and the (scarce) info I found online did indicate it was standard ATX, but I didn't want to take any unnecessary risks so I kept the old PSU in and moved it to the Antec case as well.

The main reason I kept this system is because I didn't have any money for anything better (the PC that was supposed to replace my Phenom II had also died and no money etc) and the i7 7700 that is in it was good enough for me anyway.

This board doesn't even seem to use a standard sized CPU mounting system or at least the CPU HSF I had wanted to use to replace the stock noisy one didn't seem to be able to fit.

there are some legit x58 boards on ebay, with reasonable prices, if one is willing to look at international sellers.

Eg: item 234722595694, it appears to be a working x58-ud3r board, with i/o shield for $49, excluding shipping; that seller has also many other interesting x58 boards (disclaimer: i have no personal experience with this seller).

Tetrium wrote on 2023-06-07, 08:26:

HP seems to like doing the mounting hole thing. At some point I was gifted a very small HP PC which came in a tiny (and for my t […]
Show full quote

The Serpent Rider wrote on 2023-06-05, 02:10:

Also Z400 does not match standard ATX mounting holes 100%, so you might need some slight modding for 2-3 non-standard mounting holes in your case.

HP seems to like doing the mounting hole thing.
At some point I was gifted a very small HP PC which came in a tiny (and for my tastes too noisy) ATX-alike case. I wanted to transplant it to a new case (a 'new' case made by Antec which at least had better cooling options than the old case) when I found out the mounting holes didn't match up. Of the 4 holes, only one had the correct spot with the other 3 being in different spots. I still managed to botch the HP motherboard into the Antec case by using some of that electrical isolation tape for the 3 not matching standoffs, a piece of plastic stuck in the top of the case using double sided sticky tape to press the board against the tray and a block of glued plywood sawed to the millimeter on which the motherboard rests.
I'm actually typing this message from that system 🤣.

The PSU seemed to have the correct color coding for standard ATX and the (scarce) info I found online did indicate it was standard ATX, but I didn't want to take any unnecessary risks so I kept the old PSU in and moved it to the Antec case as well.

The main reason I kept this system is because I didn't have any money for anything better (the PC that was supposed to replace my Phenom II had also died and no money etc) and the i7 7700 that is in it was good enough for me anyway.

This board doesn't even seem to use a standard sized CPU mounting system or at least the CPU HSF I had wanted to use to replace the stock noisy one didn't seem to be able to fit.

I am using a "stone" computer (different from my LGA1366 computer) this one is a LGA1155 using an extremely hot i7-3770 with absolutely terrible ventilation. I have never tried to attemp to get a bigger case, but I am pretty sure that the motherboard is also propietary. At least the PSU it is and impossible to remplace...

I would have used sugru to achieve what you did.

mihai wrote on 2023-06-07, 20:43:

there are some legit x58 boards on ebay, with reasonable prices, if one is willing to look at international sellers.

Eg: item 234722595694, it appears to be a working x58-ud3r board, with i/o shield for $49, excluding shipping; that seller has also many other interesting x58 boards (disclaimer: i have no personal experience with this seller).

Actually it is very interesting, but with the shipping it goes up to 100 sterling pounds, and I am not sure I would have to deal with customs, but that can be about 20 pounds extra only as a fee, plus whatever charges that it might have...

Sphere0161 wrote on 2023-06-07, 21:35:

Tetrium wrote on 2023-06-07, 08:26:

HP seems to like doing the mounting hole thing. At some point I was gifted a very small HP PC which came in a tiny (and for my t […]
Show full quote

The Serpent Rider wrote on 2023-06-05, 02:10:

Also Z400 does not match standard ATX mounting holes 100%, so you might need some slight modding for 2-3 non-standard mounting holes in your case.

HP seems to like doing the mounting hole thing.
At some point I was gifted a very small HP PC which came in a tiny (and for my tastes too noisy) ATX-alike case. I wanted to transplant it to a new case (a 'new' case made by Antec which at least had better cooling options than the old case) when I found out the mounting holes didn't match up. Of the 4 holes, only one had the correct spot with the other 3 being in different spots. I still managed to botch the HP motherboard into the Antec case by using some of that electrical isolation tape for the 3 not matching standoffs, a piece of plastic stuck in the top of the case using double sided sticky tape to press the board against the tray and a block of glued plywood sawed to the millimeter on which the motherboard rests.
I'm actually typing this message from that system 🤣.

The PSU seemed to have the correct color coding for standard ATX and the (scarce) info I found online did indicate it was standard ATX, but I didn't want to take any unnecessary risks so I kept the old PSU in and moved it to the Antec case as well.

The main reason I kept this system is because I didn't have any money for anything better (the PC that was supposed to replace my Phenom II had also died and no money etc) and the i7 7700 that is in it was good enough for me anyway.

This board doesn't even seem to use a standard sized CPU mounting system or at least the CPU HSF I had wanted to use to replace the stock noisy one didn't seem to be able to fit.

I am using a "stone" computer (different from my LGA1366 computer) this one is a LGA1155 using an extremely hot i7-3770 with absolutely terrible ventilation. I have never tried to attemp to get a bigger case, but I am pretty sure that the motherboard is also propietary. At least the PSU it is and impossible to remplace...

I would have used sugru to achieve what you did.

I think one of the reason why I got away with this, is because the board itself isn't very heavy with the dinky stock HSF. Btw I forgot to mention that the graphics card also helps a bit to hold the motherboard in place. It doesn't exert a lot of force on the graphics card so I think it will be fine.
Had I had to use a larger CPU HSF, I'm not sure if I would have needed to come up with a more ...resilient solution to remount such a HP motherboard if I had for instance mounted a larger 3rd party CPU HSF. But imo it was totally worth it to move the system to the Antec case as it's much cooler and more silent now (and also a bit more stable due to less accumulation of dust even though it still uses the same small coolers).
The i7 7700 and GF1050 don't run very hot, so the single 12cm exhaust I have in the Antec case will suffice.