98 is unstable at 512mb. The sweet spot is 384mb of ram.
This was fixed years ago. As with every platform there's always a large community that refuses to let go and keeps the obsolete ticking. A few tidbits regarding Win98/Dos:
Win98 installer can be patched (or afterwards) to facilitate over 512mb ram
Large SATA drives etc run fine.
Features of XP etc can be used on 98 now. Modernish browsers kinda work etc (Not really good to have imo)
Soundblaster emulators for DOS enable native DOS gaming on modern machines.
So, you can have a quad core processor with 2gb RAM that multiboots 98 up to Windows 10 with DOS gaming (in a limited capacity). Not an ideal machine (for anything) but it's fun to mess around with. Top end PIII with a GeforceFX or a VIA C3 makes a great retro gaming PC for anybody that's interested.