Why same gigabyte MB can OC RAM or not depending witch Rev

[ststns]

For exemple GA-H61M-DS2 max Ram speed:
rev. 1.0 : 1333
rev. 1.2 : 1333
rev. 2.0 : 2200
rev. 2.1 : 2200
rev. 2.2 : 2200
rev. 3.0 : 2200
rev. 4.0 : 2200
rev. 5.0 : 1333

GA-H61M-S1 max Ram speed:
rev. 2.0 : 2200
rev. 2.1 : 2200
rev. 2.2 : 1333
rev. 3.0 : 1333
rev. 4.0 : 1333

Yes there are some component differences, but they are very similar, it looks to me that it’s just a bios thing. Sure the 2200 could be more prepared.
Cloud the 1333 versions OC to 2200 with its hardware?
Are there any group/enthusiast making unofficial bios for these basic gigabyte's boards?

 

[MCID47]

Those memory speeds are depends on the motherboard chipsets and cpu memory controller itself. Rev. Can actually means the production number, such as build number on windows, but Rev(ision) number in motherboard are more simple.

 

[ststns]

Those memory speeds are depends on the motherboard chipsets and cpu memory controller itself. Rev. Can actually means the production number, such as build number on windows, but Rev(ision) number in motherboard are more simple.

I know what rev is, mostly the same MB, but with some changes.

And since the Ram is controlled by the CPU, and the chipset is the same ( H61 right? ) I was wondering if the limitation are mostly in the bios, for marketing or whatever reason, and with an unofficial modified Bios, you can OC the Ram to 2200 on any rev.