Reply 20 of 37, by Eep386
Personally, I actually would recommend the DX4 Overdrive over the other upgrades if you can find it cheap. Internally it's close enough to the Intel 486DX2 that often even the buggiest and most backward BIOSes work just fine with them. Sometimes particularly old and nasty Award BIOSes struggle with the Am5x86-133 upgrades, and Pentium Overdrive support is highly dependent on both the motherboard chipset and the BIOS for it to work its best.
I've had a card exactly like that very GD5429 many years ago. If it has 60ns rated memory, it ought to be plenty quick enough for a 486 game box. (And you can squeeze a little extra performance out of it using the CIRBOOST utility.) I also noticed you found a QD6500 VLB card. That's a really good one, especially if you can find someone to burn an XT-IDE BIOS ROM chip to plug into that vacant slot. (What the XT-IDE BIOS ROM will do, is make using a hard drive larger than 503MB much less painful to set up and use. Many old 486 boards have incomplete or even non-existent LBA support, meaning you're often stuck with a 503MB or, if you're lucky, 2GB or so maximum drive size otherwise.)
Life isn't long enough to re-enable every hidden option in every BIOS on every board... 🙁