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I'm not 100% sure, but I think there can be issues with the AGP to PCI-E bridge chip that the PCI-E Geforce FX cards use. The FX series was not built to natively support PCI-E, so the bridge chip sits between the GPU (AGP) and the PCI-E interface, basically.

I may be misremembering, but I would recommend doing a bit of research on the Geforce PCX series as well as the Quadro FX1300 (effectively a much lower-clocked FX 5900 with a PCI-E bridge chip) Windows 9x compatibility with regards to the bridge chip. If there aren't any GPU compatibility issues, then yes, I think it would make a nice setup.

That said, it can be a bit finicky getting newer motherboards working in such old operating systems. Sometimes the various controllers and parts of the more modern chipsets require jumping through some hoops to get everything working smoothly. I think ACPI (power management) gave me some trouble when I set up an Intel 800-series chipset in 9x, and that is a generation or two older than what you're thinking of using. It can be done, but it might be a project.

Regarding the processor... I'll let someone else give input on that. I'm really not that experienced with P4s from this time period. I was using Athlons throughout the whole Netburst era.

If it's really cheap, then maybe. There's nothing special in S478 i945, in fact most would consider it to be a huge nerf. Not only you're locked out of more desirable Core 2 CPUs, but also from Pentium 4 Cedar Mill. GeForce PCX 5750 is worth getting for novelty, but it's noticeably hampered by inability to use older drivers.

That motherboard looks like it really wants an 800FSB HT cpu in it.

Wonder how the sata and onboard lan will fare in 98.

As far as pentium 4 systems go, they are quite scavengable these days. I would just use whatever I could find laying about for free, especially when not very specific on which cpu to go for (which makes total sense these days - anything from the celeron to the HT prescott with HT disabled should do just fine with 9x)

The Serpent Rider wrote on 2026-02-03, 03:10:

If it's really cheap, then maybe. There's nothing special in S478 i945, in fact most would consider it to be a huge nerf. Not only you're locked out of more desirable Core 2 CPUs, but also from Pentium 4 Cedar Mill. GeForce PCX 5750 is worth getting for novelty, but it's noticeably hampered by inability to use older drivers.

Well, at first I wanted to go S478 because I thought that the early NetBurst CPUs would be the easiest to bring down to acceptable Windows 98 performance as to not cause any issues with the CPU being too fast, but if that's not an issue the only other thing special about S478 to me is just the novelty of it. Over the years I've handled TONS of AM2 and 775 boards and even if I were to build an XP machine, I'd still probably go with 939 because of how done I am with s775 and AM2(in fact I think I have a A8N-SLI Premium sitting in a box somewhere waiting for that to happen). I'm just hoping that some of the 50 series drivers will be able to work with the card PCX 5750. If I can manage to get that working, we're golden. If I run into games that don't like those driver versions I could always chuck in a PCI FX5200 and run 40 series drivers as a backup. If I can make this PCX 5750 play nicely with Win98 drivers, maybe down the line I can look into swapping the motherboard for another one with better Windows 98 support, even if it were on another socket.

If Windows 98 supports it I'm probably gonna go with a 2.8-3.2GHz P4 with 800 FSB. Do Northwood and Prescott perform/heat up pretty much the same or should I try to aim for one revision specifically?

I'll still wait a bit more before biting the bullet on this combo, maybe someone with more insight chimes in by then.

Northwood - HT enabled cores already have late revisions. Some have 30 caps on the bottom (instead of standard 12 caps) and on average better overclockers.
Presscott - all trash, realistically, but E0 and G1 supposedly have less TDP.

The Serpent Rider wrote on 2026-02-03, 09:32:

Northwood - HT enabled cores already have late revisions. Some have 30 caps on the bottom (instead of standard 12 caps) and on average better overclockers.
Presscott - all trash, realistically, but E0 and G1 supposedly have less TDP.

I found a thread that you were pretty active in with posts pretty much confirming what I feared the most. While I might still get the PCX5750 just to have it as a display model, at this point I'm having a hard time convincing myself to get the AsRock 9i945GC motherboard. I just don't see a build I'd use it in. I mentioned having a good Asus 939 board I'm saving for a DX9 PCI-E build(perhaps I could even go with SLI/Crossfire).

In the meantime I found a listing for Asus CT-479 adapter card with Dothan 760 and Asus P4p800 Se motherboard. It's listed for ~$300. Even though this is much more than I intended on spending, I can't say that I'm not tempted, but I read that the USB ports might blow up the mobo, so that kinda kills some of the enthusiasm. There's also listings for 2 Kontron mini ITX boards(one with AGP and one with PCI-E) for even more money. The AGP one is a s479 board, the 886LCD-M/mITX motherboard, but with a soldered in 800MHz Intel SL8XT Celeron(which might not be that bad for a Windows 98 PC now that I think of it). The PCI-E one is a 986LCD-M/mITX with a socket, but that kinda isn't as appealing.

All in all, it seems like this wasn't as good of an idea as I first thought, but thanks for your replies guys.

AFAIK only breakout USBs are not shielded on some boards with ICH5/ICH5R south bridge. USB ports from ATX I/O are fine.

Ozzuneoj wrote on 2026-02-03, 02:29:

Welcome to VOGONS! 🙂 […]
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Welcome to VOGONS! 🙂

I'm not 100% sure, but I think there can be issues with the AGP to PCI-E bridge chip that the PCI-E Geforce FX cards use. The FX series was not built to natively support PCI-E, so the bridge chip sits between the GPU (AGP) and the PCI-E interface, basically.

I may be misremembering, but I would recommend doing a bit of research on the Geforce PCX series as well as the Quadro FX1300 (effectively a much lower-clocked FX 5900 with a PCI-E bridge chip) Windows 9x compatibility with regards to the bridge chip. If there aren't any GPU compatibility issues, then yes, I think it would make a nice setup.

That said, it can be a bit finicky getting newer motherboards working in such old operating systems. Sometimes the various controllers and parts of the more modern chipsets require jumping through some hoops to get everything working smoothly. I think ACPI (power management) gave me some trouble when I set up an Intel 800-series chipset in 9x, and that is a generation or two older than what you're thinking of using. It can be done, but it might be a project.

Regarding the processor... I'll let someone else give input on that. I'm really not that experienced with P4s from this time period. I was using Athlons throughout the whole Netburst era.

Far as I know the bridge used is the same as AGP bridged cards (BR02 I think it was) so probably they're on the same level of compatibility.

All PCX cards require newer driver, because ForceWare 5x.xx is not aware of the bridge.