PDEP/PEXT is available all the way down to Haswell, this would be incredible if we could get a BIOS mod for this or for UBUTool to have it @SoniX
That would be really great. Hopefully somebody figures out how to do that.
Bump, this would be really great if someone found out it was possible.
we need rBAR on Haswell(+) 
I’m also looking forward to know if it’s possible on x299.
MSI MPG Z390 GAMING PLUS has just had a new BIOS released (7B51v1D);
It has begun!
[Edit] Location in AMIBCP;
This MSI web page lists Intel 300 series chipsets that are all 14nm, no mention if 22nm chipsets are compatible.
[Edit2] ASRock have also supplied a C.A.M. (Clever Access Memory) Beta BIOS for the Phantom Gaming 4 Z390 (link to reddit and Beta BIOS 4.40H).
Location in AMIBCP;
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Gigabyte released it for Z390 boards as well
https://www.gigabyte.com/us/Motherboard/…support-dl-bios
Heres hoping some of our gurus can port it to older chipsets
@pepeo Yes, you are correct! I just downloaded Beta BIOS F10k for my Z390 UD (although it is not listed on the Z390 UD product support page yet) and it has “Re-Size BAR Support”;
Bump…would love to see someone figure this out.
EVGA released BIOS/UEFI with Re-Size BAR Support for x299 boards recently.
In ASUS forum some user modded himself (can’t post link).
If X299 is possible, than Z370, Z270, Z170, H270, B365, B250 and H310A/C will be physical SAMable as well, but that was to be expected as H410 and B460 use the same silicon (Union Point). Likely Sunrise Point (H110, B150, H170, Z170) can use the same code, so if anyone manages to transplant it, I want to see this implemented in the next CoffeeTime release.
Haswell I/O-Hubs however do use quite a different technology. If it is purely a CPU setting, it should still work, but as I have not yet seen rBAR-on-CPU-only switches, PCH specific support might be included and Z87/Z97 do even use a different processor architecture for running IME & Co.
already in my Z10 board "above 4g decoding"
From what I understood “above 4G decoding” isn’t the same feature merely prerequisite for it. Would be great if someone could test that. I can’t since i have “above 4G decoding” capable Z170 board but not compatible GPU.
Nothing to do with it, and its a not a simple mod required, chipset has as word to say on the subject and dont excepct advances on the subject.
bump
any x99?
Above 4G decoding enables you to address the entire GPU memory in BAR, but it does not allow Resizable transmitting units to be negotiated between system and GPU. So even though all memory can be addressed, we require negotiation capability to allow the system to go beyond PCIe2.0 transmission limits.
This should have been implemented on every motherboard since Haswell, but they didn’t as it was an optional PCIe3.0 feature.
EDIT: Grammar
Will not be possible in anyway in old systems due to chipset architecture and internal protocol negotiation, at least below 300 Series, even with an recent UEFI GOP enable/PCIe 4.0 GPU, period!
Isnt this feature only beneficial if you have a 3000 nvidia series or AMD 6000 series card? Fwiw if modders (like Dsanke) can backport the bios of an Apex X onto an Apex IX I would imagine its possible if the board is similar? Also love to see the memory of sli cards combined. Wonder if thats even possible?
Thanks
The feature will require a motherboard/processor combo that supports Resizable BAR, a supported BIOS (&vbios) and a graphics card (&driver) that supports the PCIe Resizable BAR function
If i recall correctly, MSI already has enabled support for a wide range of motherboards, Intel 500-series, 400-series and 300-series chipsets and AMD TRX40, X570, B550, A520, X470 and B450 etc
Fyi,AMD has a different name for this,Smart Access Memory.and just like AMD’s implementation,Resizable BAR gives the processor access to the VRAM on the graphics cards
Graphics cards usually have a limitation of amount of VRAM that is accessible by the processor. He limit is 256MB of VRAM memory for the buffer running under the PCI bus.
Under the 256MB limit, the GPU firmware and operating system dictated its use. A VRAM memory space that was left to the processor’s free access.
It was on January 22, 2008 when the capacity was proposed Resizable BAR, which would be admitted on April 24, 2008. This technology is integrated within the PCI Express 3.0 standard.
This technology allows the processor can access all the VRAM memory. The only restriction is imposed by the GPU and the amount of VRAM you need to load textures and other elements.
As an anecdote, who proposed this solution were Hewlett-Packard and Advanced Micro Devices, come on, HP and AMD. Both companies were the ones that presented the idea to PCI-SIG, who manages the PCI Express standard
Under the 256MB limit, the GPU firmware and operating system dictated its use. A VRAM memory space that was left to the processor’s free access.
It was on January 22, 2008 when the capacity was proposed Resizable BAR, which would be admitted on April 24, 2008. This technology is integrated within the PCI Express 3.0 standard.
This technology allows the processor can access all the VRAM memory. The only restriction is imposed by the GPU and the amount of VRAM you need to load textures and other elements.
As an anecdote, who proposed this solution were Hewlett-Packard and Advanced Micro Devices, come on, HP and AMD. Both companies were the ones that presented the idea to PCI-SIG, who manages the PCI Express standard
