The fast or slow BIOS loading is  unrelated to the system installed. I would like you to tell us what kind of BIOS do you have and check the following settings:

1. Memory Check on boot (lots of slow-down before the BIOS floods the RAM fully, may be disabled)
2. Boot priority. Enable the drive the system is on, disable or move down the list all other devices in order of importance.
3. Graphics Chip Selection. If you are not using the on-board chip, set it to PCI-E rather than auto.
4. SATA/IDE Drive Configuration. Detect the settings and save them rather than keeping them at Auto.
5. Memory Settings. Do the same as above - detect and save the settings rather than leaving them on auto-detect.
6. Overclocking. Return the values to stock ones if they are not default. In the event of a too fast frequency setting, CMOS detects the default one and uses it, often without notifying the user and slowing booting down.

If the issues remain, try using Fail-Safe Settings or return the mainboard to Factory Settings. If that does not help, send me photos of each and every BIOS menu there is.

Also, make sure it is the BIOS that causes boot lag - if you mean the bootloader then it's a different issue entirely.