In the lot of the other hw I got my hands on the motherboard Matsonic MS9127 (aka ECS L4VXA2) https://theretroweb.com/motherboards/s/ecs-l4vxa2-1-0 with the chipset VIA P4X400 and during testing I accidentally found an interesting thing: on the board was the original BIOS without the version designation, with the assembly date 2/9/2002. In the quick Everest test, the memory throughput at writing was about 830 MB/s. After upgrading the BIOS to the last version from 10/1/2003, I was surprised to find that the throughput in this test dropped significantly to about 550 MB/s, on the same setting.
Since the original BIOS from 2002 neither on Retroweb nor on the ECS web (the Matsonic web site is loooong over), I'm putting the original faster BIOS file here just in case and the owners of these two mobos.