Attempting to enable Resizable BAR with RTX 3070

[SpiritMolecule]

Hello, any help would be appreciated as I've been attempting to get this done for awhile now with no luck.
I am simply trying to enable resizable BAR on my system.

It is enabled in BIOS along with the other necessary settings, but still seems to be disabled when checking in the Nvidia app and GPUZ.
Some digging around on the internet leads me to believe it is an issue with my VBIOS

However, I am unable to update the VBIOS using the ASUS utility as it simply gives the message "Your VBIOS does not need to be updated."

I am posting some screenshots of relevant information along with this post. Thank you in advance as I am very clueless/ inexperienced with this!

 

[agent_x007]

What is your motherboard (+BIOS version or date) and CPU ?
IIRC, there were some MBs that had a bug that needed 4G decoding to be enabled and ReBAR set to "Disabled" for it to actually work (or was it opposite, ie. "rebar on", "decode off" ?).
I'm not sure if this was later fixed.

 

[Solaris17]

What is your motherboard (+BIOS version or date) and CPU ?
IIRC, there were some MBs that had a bug that needed 4G decoding to be enabled and ReBAR set to "Disabled" for it to actually work (or was it opposite, ie. "rebar on", "decode off" ?).
I'm not sure if this was later fixed.

This, it sounds like a definite bios issue. The vBIOS should not matter in the slightest, by the time 3xxx series came out they were compatible. Only 2xxx series cards (and then even only some) needed vbios updates. Some released late enough to have the needed modules.

You should probably start with what EXACTLY you have checked or otherwise enabled in the BIOS.

 

[meatwar]

MB seems to be a new model (not specified...) as it supports PCIe 4.0, so get to bios and enable it (RBAR), that should be enabled by default bios in current standards..., unless bios is too old and needs update. that's the culprit.

 

[:D:D]

Sounds like VBIOS needs updating but ASUS updater is being naughty. Can extract updated VBIOS from package and use table list to see which ones (dual BIOS?) IIRC and nvflash.

The vBIOS should not matter in the slightest, by the time 3xxx series came out they were compatible. Only 2xxx series cards (and then even only some) needed vbios updates.

Maybe some human memory problems @Solaris17

Some early 30 series came with resizable BAR capped to 256MB. All the VBIOS updates did AFAICT is change that cap (1 nibble) to suit the VRAM Size. 20 series was a hack, not a VBIOS change.

 

[_roman_]

it (RBAR)

I'm not sure MSI or ASUS mainboards call it differently.
Some ASUS mainboards has still a bug where some settings are visually enabled but broken. Only fix - firmware flash - try again with everything entered fresh - not from the saved usb profile.
Note firmware flash = cmos reset -> new uefi from the mainboard homepage flash = different version = preferred - newer version -> enter all settings by hand

It's not that easy to enable stuff on some mainboards. For some reason.

--

Note: We are waiting for a reply from the original topic poster.

 

[eidairaman1]

Update your motherboard bios first, then see if that feature is even in it.

You never told us what mobo you have or cpu

 

[Ruru]

Hard to say before OP tells what platform he/she is using.

Sounds like VBIOS needs updating but ASUS updater is being naughty. Can extract updated VBIOS from package and use table list to see which ones (dual BIOS?) IIRC and nvflash.

I'm 99.99% sure that it's not a VBIOS issue since doesn't RTX 30 cards support ReBAR straight outta the box?

 

[eidairaman1]

Hard to say before OP tells what platform he/she is using.


I'm 99.99% sure that it's not a VBIOS issue since doesn't RTX 30 cards support ReBAR straight outta the box?

Its a hit and miss certain conditions must be met.

A 4GB+ GPU is required, CSM must be disabled. And rebar is not some miracle performance boost that everyone thinks it is.

 

[Ruru]

Its a hit and miss certain conditions must be met.

A 4GB+ GPU is required, CSM must be disabled

Well, at least on the desktop side, there aren't any RTX cards which have less than 6GB VRAM.

 

[eidairaman1]

Well, at least on the desktop side, there aren't any RTX cards which have less than 6GB VRAM.

Giving the minimums is why

 

[Ruru]

Giving the minimums is why

Saw your ninja edit above, isn't ReBAR anyway just a marginal speed boost even in the best scenarios (except for Intel GPUs)?

 

[eidairaman1]

Saw your ninja edit above, isn't ReBAR anyway just a marginal speed boost even in the best scenarios (except for Intel GPUs)?

I found a page from here that gives a general description.

ReBarUEFI is a Boot Time Module that Enables Resizable BAR on Some Older Platforms

Officially, support for resizable BAR on the Intel platform begins with the 10th Gen Core "Comet Lake," and for AMD, the Ryzen 3000 "Zen 2." It is a PCI-SIG feature that allows the software to see the entire amount of video memory on your graphics card as a single contiguous addressable block...

www.techpowerup.com

Zen 2 and core i10 is minimum Requirement, that leaves the mobo having the setting.

I only know the b550 steel legend has it in bios, so other mobos idk.

 

[INSTG8R]

As someone mentioned earlier I know in my BIOS by default ReBar was enabled but 4G was disabled and greyed out. You have to disable RreBar that allows you to enable 4G then re-enable ReBAR

 

[Solaris17]

As someone mentioned earlier I know in my BIOS by default ReBar was enabled but 4G was disabled and greyed out. You have to disable RreBar that allows you to enable 4G then re-enable ReBAR

one of my AM4 boards (wish I remembered which it was) did this. If I clicked the "Rebar Enable" like toggle on the main bios page literally would not function. I had to shut it off, then go into the pcie settings and enable above 4g encoding.

 

[INSTG8R]

one of my AM4 boards (wish I remembered which it was) did this. If I clicked the "Rebar Enable" like toggle on the main bios page literally would not function. I had to shut it off, then go into the pcie settings and enable above 4g encoding.

Yeah basically one setting is blocking the other, and why only one of the two being enabled when it does nothhing without the other one,..

 

[eidairaman1]

Yeah basically one setting is blocking the other, and why only one of the two being enabled when it does nothhing without the other one,..

Yeah i saw those functions in the SL board, the user of that board is not a gamer and is running W11 using a R7 250X Ghost. Anyways we wont know until the op gives mobo and cpu details

 

[:D:D]

@SpiritMolecule You can check your VBIOS is capped at 256MiB by maybe checking GPU-Z "message" or dumping VBIOS and attaching.

If it's AS10 then it's capped to 256MiB.

 

[eidairaman1]

Op gave us vague info, we don't even know if the system is capable of it to begin with .

 

[:D:D]

Hard to say before OP tells what platform he/she is using.

Right

I'm 99.99% sure that it's not a VBIOS issue since doesn't RTX 30 cards support ReBAR straight outta the box?

Sorry I didn't get back to you earlier, some info on Asus site from 2021.

Guide: How to enable Resizable BAR on your ASUS-powered gaming PC - Edge Up

Learn how to boost your ASUS-powered PC's performance by following this handy guide to enabling Resizable BAR.

edgeup.asus.com

All of our GeForce RTX 3060 graphics cards support Resizable BAR out of the box. However, a video BIOS (VBIOS) update is required before Resizable BAR can be enabled with our GeForce RTX 3060 Ti, GeForce RTX 3070, GeForce RTX 3080, and GeForce RTX 3090 graphics cards. We provide self-contained VBIOS updater packages through our product support pages.

Not sure what the OP has, if it's AS10 then it doesn't seem to appear in the Asus update tool. Of course it could be already good and a mainboard BIOS problem but thought it might be an easy check.

 

[Dr. Dro]

Initial batches of OG non-LHR RTX 3060 through 3090 (with BIOS dates of 2020) have no ReBAR support. BIOS must have the following settings:

- ReBAR: Auto
- Above 4G Decoding: Enabled
- CSM: Disabled
- OS installed in UEFI mode

1. Backup original BIOS using GPU-Z

2. Download latest VBIOS and nvflash from TPU

Asus RTX 3070 VBIOS

8 GB GDDR6, 1500 MHz GPU, 1750 MHz Memory

www.techpowerup.com

NVIDIA NVFlash 5.821.0 Download

NVIDIA NVFlash is used to flash the graphics card BIOS on Ampere, Turing, Pascal and all older NVIDIA cards. NVFlash supports BIOS flashing on NVID

www.techpowerup.com

3. Rename the downloaded VBIOS as GA104.rom for convenience

4. Run CMD as administrator, point out to nvflash folder and then issue the following command:

nvflash64 GA104.rom

If more than one NVIDIA GPU is present on the system use the nvflash64 --list command before and -i(number) to choose the correct card

5. Reboot with shutdown -r -t 0 after the process is complete

6. If BIOS settings are correct, no further configuration will be required and the driver will enable Resizable BAR without further user input. System Information in NVIDIA Control Panel will say Resizable BAR "Yes" and GPU-Z will show a BAR1 size of the full GPU memory capacity

Let us know if you need any further help.

 

[Ruru]

Initial batches of OG non-LHR RTX 3060 through 3090 (with BIOS dates of 2020) have no ReBAR support.

Interesting, my 3080 TUF has a receipt from 17.9.2020, though I'm maybe the third owner so could be updated before I bought this.

 

[Dr. Dro]

Interesting, my 3080 TUF has a receipt from 17.9.2020, though I'm maybe the third owner so could be updated before I bought this.

View attachment 377817

Yup, it most definitely was. My 3090 that I ordered at launch did not have ReBAR enabled either, that came on an update a few months down the road.