Welcome !
As a Win98 box this is pretty decent/on the overkill side for the CPU/RAM.
The matrox G450 may be a little bit underpowered for later games, but it should be pretty decent for most of them. Try games first and if that's good enough for you, keep that card.

As for DOS games, there it can become tricky because of your sound card. It all depends of the games you want to run actually. The DOS games you're listing should run with no issues on your setup though.

For the PSU, anything over 200/250W should be pretty good, unless you aim for the fastest CPU the socket A plaftorm provided. However there is one big problem with PSUs and socket A : most of the power is taken from the 5V rails. This shouldn't be a problem normally, except that nowadays newly made PSUs are made for 12V rail power, not 5V.
Back then the beefiest PSUs could deliver up to 35/40A on the +5V, meanwhile nowadays they rarely get over 20/25A for +5V.

Now this shouldn't be a big issue either if you use an older and less power consuming CPU.

Deksor wrote on 2020-06-26, 00:45:

However there is one big problem with PSUs and socket A : most of the power is taken from the 5V rails.

This is either incorrect or it depends on the motherboard. Below you should see with my Dual Socket A Athlon MP system the +12 power is higher than the +5 power.

I also have Windows Me on that system with all 2GB being available once you have patched it. As I recall the patch also works for 98.

Well maybe your board has a +12V cpu connector ? But most socket A boards (including his board) don't work that way.

As for the ram sure you can get to 2GB, but what's the matter ? ^^ do you need it for something ? 😀
My windows 98 pc has 128MB and it doesn't lag for anything at all (the old pentium 2 will be the culprit of slowdowns way before the ram in my case). I'd say 256MB is really the maximum ram you'll ever truly need in a windows 9x PC where it'll make sense.
More ram means you're running apps that don't necessarily need 9x and thus that you'd be better off with XP ^^

Now you do what you want with your machines and since your is a dual CPU machine and that your screenshot is showing xp I believe you have a dual boot, so in your case it makes sense, but I just find rather strange people go crazy with the ram amount they install in their retro PCs these days.

Deksor wrote on 2020-06-26, 09:15:

As for the ram sure you can get to 2GB, but what's the matter ? ^^ do you need it for something ? 😀

Now you do what you want with your machines and since your is a dual CPU machine and that your screenshot is showing xp I believe you have a dual boot

It matters as by default Me won't boot with 2GB installed unless it's patched and I expect 98 is the same. I installed 2GB as I found 2GB in my box of spare DIMMs and may install Windows 7 at some stage.

The screenshot is actually showing Windows 2003 x32 Enterprise Terminal Server R2 so I am at a loss as to how you can say it's "showing xp". The system it Triple Boot.

Sure, but by that I mean, why using 2GB with any windows 9x except for some weird experiments (or in your case multi boot).

Also I don't know much about windows from the 2000's, I saw it had the "xp era" logo and the luna theme so I assumed "XP" by default, but you're right it's Windows 2003.

red-ray wrote on 2020-06-26, 08:54:

Deksor wrote on 2020-06-26, 00:45:

However there is one big problem with PSUs and socket A : most of the power is taken from the 5V rails.

This is either incorrect or it depends on the motherboard. Below you should see with my Dual Socket A Athlon MP system the +12 power is higher than the +5 power.

It does, and yours is basically the unicorn. Dual SoA is a beast, and for that reason a by the time the 760MPX chipset came along, the then-current AMD spec to draw CPU power from 5V was abandoned and CPU power moved to 12V, as was already being done on P4 and planned for Athlon64. You clearly have one of those boards. Something like the A7M266-D, GA-7DPXDW-P or Tyan Tiger MPX by any chance?

There most definitely were dual SoA boards that didn't do that (like the Tyan Tiger MP), and they drew *massively* from the 5V line, with a fully decked out system needing 200W/40A. The trouble in delivering that is why later dual SoA boards moved to the solution you had. Single SoA was also power-hungry, but not in the same league as dual - absolute worst-case you'd draw about 30A on the 5V line if getting CPU power from it (of which 16A is CPU, maybe 4A for regulators and the rest AGP and PCI). That was perfectly doable by any decent 2002-era PSU, so there was no need for new engineering to draw CPU power from 12V. That does give you a big problem with new PSUs, as 5V draw these days is minimal, so you'll need a massively over-specced unit to get that 30A...

But some did do the engineering. This Abit KV7 is one of the very last SoA boards, and if you look at a pic, it has an ATX12V connector next to the CPU. It's also one of those late unicorns. That's good news, as it means it draws CPU power from 12V, so is suited to any low-end but decent modern PSU. Go for a good brand and low wattage (300W is more than enough) and you're fine, OP 😀

dionb wrote on 2020-06-26, 12:02:

This Abit KV7 is one of the very last SoA boards, and if you look at a pic, it has an ATX12V connector next to the CPU. It's also one of those late unicorns. That's good news, as it means it draws CPU power from 12V, so is suited to any low-end but decent modern PSU. Go for a good brand and low wattage (300W is more than enough) and you're fine, OP 😀

Oh you're right ! I didn't see that at all, so I assumed it was one of the regular socket A board which draws a lot from +5V.

Well @OP you won't have any issues with new PSUs then.

dionb wrote on 2020-06-26, 12:02:

Something like the A7M266-D, GA-7DPXDW-P or Tyan Tiger MPX by any chance?

Thank you for the background, I did not know I had struck lucky. If you look at the screen shot it says TYAN S2466 (SIV V5.50 Beta-03 will say TYAN S2466 (Tiger MPX)) and I used to have a GA-7DPXDW-P before it died. As both have ATX12V connectors I had assumed this was usual.

Hey all, sorry for the late reply, on a family road trip for awhile... greatly appreciate the advice, parts orders imminent, thanks again!