X58 above 4G decoding support

[kelvinhall05]

Hi guys. Wondering if my Sabertooth X58 supports above 4G decoding for PCIe devices. I see lots of conflicting info online. Some people say this was introduced with X58 (or even earlier), some say X58 doesn't support it at all, some say it can be enabled with a hacked BIOS...I don't know who is right.

 

Skimming through my BIOS I don't see an option to enable it. It's possible I missed it, but is it just not supported? Thanks!

[curiousmind34]

5 minutes ago, kelvinhall05 said:

Hi guys. Wondering if my Sabertooth X58 supports above 4G decoding for PCIe devices. I see lots of conflicting info online. Some people say this was introduced with X58 (or even earlier), some say X58 doesn't support it at all, some say it can be enabled with a hacked BIOS...I don't know who is right.

 

Skimming through my BIOS I don't see an option to enable it. It's possible I missed it, but is it just not supported? Thanks!

From what I have seen it's just kind of a compatibility layer for 32 bit cpus. It doesn't matter on 64 bit cpus, and that is likely why it is not in the bios.

[kelvinhall05]

19 minutes ago, curiousmind34 said:

From what I have seen it's just kind of a compatibility layer for 32 bit cpus. It doesn't matter on 64 bit cpus, and that is likely why it is not in the bios.

Really? Everywhere I see it used, it's for PCIe devices only, and only specific ones. I plan to (try) and use it to run a Xeon Phi, but people use it for Teslas and other cards like that.

 

I also know it's not enabled because running dmesg | grep BAR= only shows BAR as 256M. If above 4G decoding was enabled it would be, well, above 4GB.