Hello all , i finally found the 3870 bios i was looking for...the bios have the 860Mhz core bug fix , and the most important feature : the speed fan is fixed. The fans of both of my HIS 3870 was stuck at 28-30% at all time. Sure it's quiet but it overheat ( 80-92c ) if you overclock. Also i was sick to disable crossfire and then set manually each card at 55% with rivatuner and re-enable crossfire each time i reboot. With this BIOS the fan speed increase dynamically versus GPU temp on BOTH card while crossfire is enabled.
I have taken some note while testing the cards :
Fan duty cycle
57c and lower : 37%
58-61c : 45%
61-62c : 55%
63-64c : 59%
65c : 62%
it could be a bit noiser for some user but it still very quiet versus a 2900XT. I don't hear them at all because i own the CoolerMaster Cosmos case with acoustic foams in the sides panel....I can't tell what happen after 65c , because my card never reached a temp higher than 65c. I still have the factory coolers with Arctic silver 5 thermal paste. I think this it great for users who don't want to shell out more $$ for Duorbs or Accelero S1... if the temps won't go higher than 65 it will stay that way for me.
Have fun .. i flashed both my card and it work fine
now just some warnings :
1- UNINSTALL ANY ATI SOFTWARE BEFORE FLASHING A BIOS
2- IF YOU CAN CALL YOURSELF A NEWBIE AND NOT COMFORTABLE WITH BIOS FLASHING , SKIP IT AND DON'T DO ANYTHING !
3- IM NOT RESPONSIBLE IF YOU DESTROY YOUR CARD , BUT YOU ARE. IT WILL VOID YOUR WARRANTY.
Fixed BIOS
http://www3.sympatico.ca/ocd/bios/3870fanfix.bin
This file below is a original 3870 BIOS , quite handy to have is something go wrong
Stock HIS HD3870 bios
http://www3.sympatico.ca/ocd/bios/HIS3870.bin
This is a ISO for a boot cd containing the required files to boot and flash your cards. The fixed bios is called 3870fix.bin and a original bios 3870.bin. Once you have booted change the prompt for your optical drive and use the usual atiflash 3.49 commands to flash right away. This boot cd might not work if you have a SATA optical drive because there's no sata driver on the cd
http://rapidshare.com/files/85513179...tbios.iso.html
IM NOT RESPONSIBLE IF YOU DESTROY YOUR CARD