I’ve been using this motherboard with an Arc A380 for Plex transcoding. Even though its performance has been great, I can’t help but feel like I’m not taking full advantage of the GPU without Above 4G Decoding and Resizeable BAR.
The original image I’m trying to modify can be found here: https://download.asrock.com/BIOS/1155/Z68%20Extreme4(L2.23)ROM.zip
I’ve followed THIS guide to enable Above 4G Decoding. I made it to step 5, and IRFExtractor extracts 8 text files when I was only expecting 1. I’m not sure why but I’ve been using NP++ to search all of them.
For “Above 4G Decoding” I get:
OneOf Prompt: “Above 4G Decoding”, Help: “Enables or Disables 64bit capable Devices to be Decoded in Above 4G Address Space (Only if System Supports 64 bit PCI Decoding).”, QuestionFlags: 0x10, QuestionId: 0x5, VarStoreId: 0x1, VarOffset: 0x1, Flags: 0x10, Size: 8, Min: 0x0, Max: 0x0, Step: 0x0
The issue I see here is that the VarOffset is 0x1, which doesn’t seem right. Is this because the information to actually use this feature is missing?
The other, seemingly similar option I found is “Max TOLUD”:
OneOf Prompt: "Max TOLUD", Help: "Maximum Value of TOLUD. Dynamic assignment would adjust TOLUD automatically based on largest MMIO length of installed graphic controller", QuestionFlags: 0x10, QuestionId: 0x1C9, VarStoreId: 0x1, VarOffset: 0x1EF, Flags: 0x10, Size: 8, Min: 0x0, Max: 0x0, Step: 0x0 OneOfOption Option: "Dynamic" Value: 0, Default, MfgDefault OneOfOption Option: "1 GB" Value: 1 OneOfOption Option: "1.25 GB" Value: 2 OneOfOption Option: "1.5 GB" Value: 3 OneOfOption Option: "1.75 GB" Value: 4 OneOfOption Option: "2 GB" Value: 5 OneOfOption Option: "2.25 GB" Value: 6 OneOfOption Option: "2.5 GB" Value: 7 OneOfOption Option: "2.75 GB" Value: 8 OneOfOption Option: "3 GB" Value: 9 OneOfOption Option: "3.25 GB" Value: 10
This looks promising, and it has an offset of 0x1EF which actually appears to mean something. I think this setting would do the same as “Above 4G Decoding” based on the description, but I’m not sure.