board is a msi4144.
according to sis496 datasheet, there are 4 dram timing presets defined for 25, 33, 40 and 50 fsb, and you can only choose one of them:
fastest: 3-2-2-2, recommended for 25fsb
fast: 4-3-3-3, recommended for 33fsb
slow: 5-3-3-3, recommended for 40fsb
slowest: 6-4-4-4, recommended for 50fsb
i am running amd5x86-133 at its rated 33*4, and i tried "fastest". it was quite fast as cachechk reported 3.4clocks per read average, and it passed a few tests, but norton sysinfo freezed at the welcome screen. choosing "fast" fixed this, but its noticeably slower as cachechk now reports 4.4clocks per read. this sounds ridiculous cause i am using 60ns dram, and i am concerned about whether i can get away with "slow" on 50fsb.
and, does this board support edo ram? this is because i don't have many fpm simms at hand.
while many people believe that edo does no help to 486 performance, both sis496 and ali1489 datasheet claimed that they can provide faster burst read with edo over fpm(5-2-2-2 over 5-3-3-3 for example), although i have not been able to find the datasheet of umc8881.
however, this also sounds meaningless because doing bursts this fast would be equally fast as 1wait cache. it may help on boards without cache though, as i have heard of cacheless ali1489 boards being quite fast with edo.