Hello all,

Tl;dr: Bold text below contains the root of the issue and what I've discovered so far...

Recently, I was working on an upgrade for my Pentium III build and decided to swap the motherboard and upgrade the CPU.

Previously, my machine had the following specifications:

• ASUS CUV4X
• Pentium III 1.0EB Coppermine-T
• 512MB PC133 SDRAM CAS3
• 3dfx Voodoo 3 3000 AGP
• Intel 10/100 Network Card
• Aureal Vortex 2 (TB Montego II)
• SoundBlaster AWE 64 Gold

It was a pretty nice machine, but I had a few problems with it. Although this pre-dates the issue I'm having, I suppose it's worth mentioning that I switched to the CUV4X in an attempt to accomplish two things: (i) pass the 512MB RAM limitation of the intel 815 chipset; and (ii) make sure that I have a board suitable for hosting my AWE64 Gold as a secondary MIDI card.

First, I found that there definitely was a slowness to the GUI that I hadn't noticed when using an ASUS TUSL2-C with the same Voodoo 3 3000 AGP. I came across this interesting thread and it seems that I am not the only one with this issue. Normally, I would not care, however I found Windows 98SE to be sluggish on both a fast CF card and SSD, and decided that enough was enough. The machine was stable, however, and seemed to provide pretty good performance in UT99, which I find myself playing quite a bit.

In an attempt to raise the bar a bit and put together a more performant machine, I purchased recently an ASUS CUBX-E, thinking that a 440BX board at 133MHz would be the way to go; 89MHz AGP aside, I figured that the board overall would offer more versatility and far higher performance. I decided to mate this with a Pentium III 1.26-S from the Korean eBayer who sells pin-modded CPUs, and used the BIOS a fellow member of this forum produced to ensure good compatibility with the board.

The machine today sits with a repasted video card known to work acceptably with 89MHz AGP, an SSD on one of those bidirectional SATA-IDE converters with the Satalink Spif223a chipset, and the following overall set of specifications:

• ASUS CUBX-E
• Pentium III 1.26-S Tualatin (pin-modded)
• 512MB PC133 ECC SDRAM CAS3
• Nvidia GeForce 4 Ti 4200 64MB
• 3COM 3C905B 10/100 Network Card
• Aureal Vortex 2 (TB Montego II)
• SoundBlaster AWE64 Gold

I figured that the 440BX chipset would be the answer here, being stable, fast, and proven. This CUBX-E worked just fine with a Penitum III 667MHz, a Pentium III 1.0EB, and the Coppermine-T from above. With the new BIOS, it was just fine with the Tualatin too--except in Windows, wherein I find the machine randomly freezing. The machine will lock up most of the time when sound on the Vortex 2 is being played and something intensive is being done on the SSD--my thoughts immediately went to there being an IRQ issue. Sometimes it'll lock up even if sound isn't playing but if I'm, say, installing a game using Daemon Tools whereby the sound card should be playing something at the menu.

I've had numerous issues with IRQs and presumed that there's something going on there: it appears that the network card was at one point conflicting with the IRQ for the Promise ATA100 controller on the board, and at another point it appears that the Vortex 2 was in conflict with the Promise controller. I swapped slots around, and now the Promise controller has IRQ10 all by its lonesome and the Vortex 2, 3COM card, and USB controller all share IRQ 9.

I've tried all I can think of--different slots, reinstalling Windows, reconfiguring drivers, a different BIOS, different RAM (although the ECC sticks used here are known good that I've had for a long time and used in a few other builds over the years), and lots of patience and hair-pulling and nothing has changed. I know the cards from the original build are all good and the board looks to be in good shape with no visible trace damage or anything; I tested it in various configurations, as mentioned above, and it seemed okay.

At this point I'm about ready to give up on the CUBX-E, but I really want an ISA slot or two in my Pentium III build. I've considered a Pentium 4 1.5GHz build with an ASUS P4T, but I don't want to yield on being able to use the AWE64 Gold just yet. I also have an FIC KC19+ and it's a nice board, with the weird but pretty decent Intel 820 chipset, however, the ISA slots don't have working DMA, as far as I can tell. Firing up DOOM or DOOM 2 doesn't give me any sound effects, neither does Wolf3D.

Part of me wishes I could find something like the ASUS P3C-E or one of its brethren, as I'm totally fine with RDRAM, and would be interested in having working ISA (by ITE8888F) and 133MHz FSB without overclocked AGP on an Intel chipset, but the rational side of me says that it's not worth going on a wild goose chase for one particular board that's pretty darn rare and with a chipset that's potentially not much better than the Apollo Pro 133A (nor is it worth the $$$ 🤣).

I suppose the question then comes down to this: Has anyone faced anything similar and, if so, what did you do to remedy the issue? I'd really appreciate any and all suggestions!

I'm sorry this is such a long post, but I figured I'd provide as much background as possible. If there's any more info y'all need to help figure this out, please let me know.

And a massive thank you in advance to all those who respond and provide some insight!