I know this isn't what you asked but DDR2 (and even small capacity DDR3) RAM is so cheap now that I would suggest buying different RAM rather than limiting yourself to DDR1. This allows for a wide range of (likely cheaper) motherboards that offer a lot more compatibility. A basic, late Socket 775 motherboard will allow you to use pretty much any 775 CPU which again allows for a dirt cheap E7XXX or E8XXX series CPU instead of hunting down a likely more expensive E6600 as you will likely be limited to Conroe (E6XXX) or even Pentium D on a DDR1 board. It will also be faster and might allow for PCI-E 2.0 which removes the (small risk) of potential incompatibility with the RX550.

The RX550 does not have XP or Vista drivers so you will be using Windows 7. W7 will appreciate the faster CPU and RAM I think, for every day usage that an "old games" machine does .e.g. downloading drivers, patches etc.

Look into Socket 939, there are plenty boards with PCIe and four DDR1 slots.

Edit: I'm not sure wether the RX550 will work with legacy BIOS though and wether there are UEFI compatible S939 boards.

Almoststew1990 wrote on 2021-03-14, 10:36:

I know this isn't what you asked but DDR2 (and even small capacity DDR3) RAM is so cheap now that I would suggest buying different RAM rather than limiting yourself to DDR1. This allows for a wide range of (likely cheaper) motherboards that offer a lot more compatibility. A basic, late Socket 775 motherboard will allow you to use pretty much any 775 CPU which again allows for a dirt cheap E7XXX or E8XXX series CPU instead of hunting down a likely more expensive E6600 as you will likely be limited to Conroe (E6XXX) or even Pentium D on a DDR1 board. It will also be faster and might allow for PCI-E 2.0 which removes the (small risk) of potential incompatibility with the RX550.

The RX550 does not have XP or Vista drivers so you will be using Windows 7. W7 will appreciate the faster CPU and RAM I think, for every day usage that an "old games" machine does .e.g. downloading drivers, patches etc.

Yes, I know it would be better to buy a new mobo, save money by buying an old pc and putting the RX on it, but I would like to use the old ram.
Not an economic factor but more for my enjoyment!
Thanks a lot for the idea anyway.

Yeah, sounds like socket 939 is what you’re looking for. Grab an opteron or athalon x2

Sonatok wrote on 2021-03-14, 10:08:

Hi everyone, I found 4 Gb (1 x 4) of DDR400 ram and i also having an RX 550 video card, case and ssd. I wanted to create a pc to […]
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Hi everyone, I found 4 Gb (1 x 4) of DDR400 ram and i also having an RX 550 video card, case and ssd.
I wanted to create a pc to use for light games.so I'm looking for a motherboard that has at least 4 DDR400 slots, a PCI slot and the ability to use CPU with 2 or more cores.
I only found cards online that support Pentium 4 ... 🙁
I found the ConRoe865PE but unfortunately it doesn't have the pci ...

Thanks to all in advance.

Wait, you mean 4x1 GB and not 1x4 GB and PCI-E and not PCI right?

What do you mean with that you found the Conroe but it doesn't have the PCI? If you found a system with a Conroe and with AGP, that could actually be interesting in its own right.

Anyway, you obviously want what is basically the most modern DDR1 motherboard you can get away with. These will have PCI-E anyway (no AGP) and many will have 4 memory slots (many will also have just 2 slots though, but you should still have ample choice).
If you can't find a suitable DDR400 Conroe motherboard, then s939 is the obvious other choice.

There was a pc chips board that supported socket 775? Agp, pci express, pci, ddr1, ddr2 all on the same motherboard. But it was only 2 slots of each respective ddr type I believe. and the agp slot was a 1x slot. I know someone who has one.

I think... it may support core 2 quads?

http://www.asrock.com/mb/via/775dual-vsta/

Maybe it was this one and not pc chips...🤔

This one says agp 8x

I think there must be two different boards on this theme because I swear that there was a board like this where they rigged the agp slot using a pci lane.

Here we go?
https://www.newegg.com/p/N82E16813135196

Agree with everyone, limiting to a DDR board with PCI-E puts some restrictions on the CPU as well as the boards.
The only Intel chipset with PCI-E and DDR 333/400 support is the 915 with 915G being the main one and is socket early 775. Intel 915GAV/GAG and ASUS P5GD1 series are examples.
https://www.intel.com/content/www/us/en/suppo … top-boards.html
The AMD 939 socket boards there are many more variants with DDR and PCI-E.