Reply 480 of 486, by ph4nt0m
The IBM Opal and Opal LX mainboards with IBM 486SLC2
AMI BIOS 06-Jun-1992, MS-DOS 6.22 with HIMEM
IBM Opal with 80MHz CPU / 40MHz system and VL buses / 13MHz ISA bus, OPTI 82C295 + 82C206 chipset, 16Kb WB L1 cache, 128Kb WB L2 cache, 16Mb FPM RAM, IIT 3C87SX math coprocessor, Hercules VL Dynamite Pro 2Mb (Tseng ET4000/W32P):
DOOM: 22.0 (3395 realticks)
The same config with a Diamond SpeedStar 64 ISA 2Mb (Cirrus Logic GD5434):
Doom: 20.0 (3743)
Again with the Diamond card and 66MHz CPU / 33MHz system bus / 11MHz ISA bus:
Doom: 16.8 (4450)
IBM Opal LX with 66MHz CPU / 33MHz system bus / 11MHz ISA bus, OPTI 82C283 + 82C206 chipset, 16Kb WB L1 cache, no L2 cache, 16Mb FPM RAM, IIT 3C87SX math coprocessor, Diamond SpeedStar 64 ISA 2Mb:
Doom: 15.0 (4978)
The same with 50MHz CPU / 25MHz system bus / 8MHz ISA bus:
Doom: 12.0 (6205)
It seems the L2 cache doesn't help much. The max improvement is 10% with Doom. A video card upgrade from ISA to VL yields 20% in 3Dbench and 10% in Doom.
BTW if anyone has the MR BIOS for these mainboards, I'd appreciate a copy.