NVIDIA RTX 20-series and GTX 16-series "Turing" GPUs Get Resizable BAR Support Through NVStrapsReBAR Mod

[btarunr]

February saw community mods bring resizable BAR support to several older platforms; and now we come across a mod that brings it to some older GPUs. The NVStrapsReBAR mod by terminatorul, which is forked out of the ReBarUEFI mod by xCurio, brings resizable BAR support to NVIDIA GeForce RTX 20-series and GTX 16-series GPUs based on the "Turing" graphics architecture. This mod is intended for power users, and can potentially brick your motherboard. NVIDIA officially implemented resizable BAR support since its RTX 30-series "Ampere" GPUs in response to AMD's Radeon RX 6000 RDNA 2 GPUs implementing the tech under the marketing name Smart Access Memory. While AMD would go on to retroactively enable the tech for even the older RX 5000 series RDNA GPUs, NVIDIA didn't do so for "Turing."

NVStrapsReBAR is a motherboard UEFI firmware mod. It modifies the way your system firmware negotiates BAR size with the GPU on boot. There are only two ways to go about modding a platform to enable resizable BAR on an unsupported platform—by modding the motherboard firmware, or the video BIOS. Signature checks by security processors in NVIDIA GPUs make the video BIOS modding route impossible for most users; thankfully motherboard firmware modding isn't as difficult. There is an extensive documentation by the author to go about using this mod. The author has tested the mod to work with "Turing" GPUs, however, it doesn't work with older NVIDIA GPUs, including "Pascal." Resizable BAR enables the CPU (software) to see video memory as a single contiguously addressable block, rather than through 256 MB apertures.



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[ArturoH4L]

Hello,
Quick question.
"GTX 16-series"
So, this is not available for my GTX 1080 then??
Thanks.

 

[Onasi]

Hello,
Quick question.
"GTX 16-series"
So, this is not available for my GTX 1080 then??
Thanks.

No, Turing only. The 10-series is Pascal.

 

[ArturoH4L]

No, Turing only. The 10-series is Pascal.

You`re completly right, Thanks.

 

[Pooch]

There is absolutely no reason for anyone to try this. Do not attempt to do anything described in this article.

 

[ThrashZone]

Hi,
Might kill board, Do it miners weren't even interested in the 16 series lol

That's a good way to buy another gpu with more than 4-6gb of vmem oops fortnite don't care hehe

 

[OneMoar]

But WHY?

 

[Tomorrow]

There is absolutely no reason for anyone to try this. Do not attempt to do anything described in this article.

It is far more complex than the article leads you to believe. The article only mentions the module itself but the user still has to separately modify the motherboard BIOS with a different program to insert this module, compile the new BIOS file and flash it.

Thankfully i have a motherboard with dual-BIOS, including switches to select which one to use. So the risk is minimal (and this is why all motherboards and GPU's should have dual-BIOS). If a flash fails i simply flip the switch to boot from secondary slot and flash stock bios back to the first slot.

Might kill board

No it wont.

But WHY?

How about free performance Nvidia refuses to give Turing owners?

 

[OneMoar]

It is far more complex than the article leads you to believe. The article only mentions the module itself but the user still has to separately modify the motherboard BIOS with a different program to insert this module, compile the new BIOS file and flash it.

Thankfully i have a motherboard with dual-BIOS, including switches to select which one to use. So the risk is minimal (and this is why all motherboards and GPU's should have dual-BIOS). If a flash fails i simply flip the switch to boot from secondary slot and flash stock bios back to the first slot.

No it wont.

How about free performance Nvidia refuses to give Turing owners?

id like to see benchmarks because the most I have ever seen gained from rebar is 5 or 8fps in select titles and generally only benifits resolutions below 1440p

 

[mtosev]

I'm too afraid of trying this on my system.

 

[Dr. Dro]

How about free performance Nvidia refuses to give Turing owners?

-5 to +5% of "free performance"? Might as well not bother.

 

[rethcirE]

But WHY?

Not that long ago people on this very forum said it would never be available for past gens. Others (including myself) asked, "Why not?"

-5 to +5% of "free performance"? Might as well not bother.

For 99% of people, I agree. For the 1% pushing the envelope, achieving world records, ACTUALLY changing the industry and breaking limits that will impact tomorrow; this matters.

Let's all read this again...

This mod is intended for power users

I believe that means this has no benefit or real purpose to a typical computer gamer or even your average overclocker.

 

[Dr. Dro]

For 99% of people, I agree. For the 1% pushing the envelope, achieving world records, ACTUALLY changing the industry and breaking limits that will impact tomorrow; this matters.

About 6 years too late for Turing WRs but I suppose it could be fun for a "retro" competition

 

[Tomorrow]

-5 to +5% of "free performance"? Might as well not bother.

Negative scaling is rare. Most games either stay flat or benefit. And we are talking about 6 year old cards here. ANY performance is welcome.
Besides it's not like someone is forcing Turing owners to do this. At least the option is out there and that's what matters.
I would prefer official option from Nvidia but since this has not happened, and likely will never happens then this mod is good enough.

If a driver update adds 5% performance people call that pretty good.

 

[ThrashZone]

No it wont.

Hi,
Read again lol

-5 to +5% of "free performance"? Might as well not bother.

Indeed why bother.

 

[Tomorrow]

Hi,
Read again lol

View attachment 338491

You said "might kill". The article says "potentially brick". One does not equal the other. I've "soft bricked" devices that appeared completely dead, only to be brought back to life trough proper procedure and without any specialized equipment or tools. There is a also the difference between "soft brick" and "hard brick" and ultimately hardware damage. People have even blind flashed BIOS with no display output.

Also like i said earlier - this a total nonissue for boards that have dual-BIOS or socketable BIOS chip.

 

[ThrashZone]

You said "might kill". The article says "potentially brick". One does not equal the other. I've "soft bricked" devices that appeared completely dead, only to be brought back to life trough proper procedure and without any specialized equipment or tools. There is a also the difference between "soft brick" and "hard brick" and ultimately hardware damage. People have even blind flashed BIOS with no display output.

Also like i said earlier - this a total nonissue for boards that have dual-BIOS or socketable BIOS chip.

Hi,
Yeah we need a rewrite to inconvenient pause of computer operation

 

[LemmingOverlord]

This reminds me of how we used to inject NVMe boot capability in older motherboards. It's just a matter of editing the BIOS and reflashing. Only works if the BIOS allows non-locked (i.e. signed) firmware, so mostly on DIY/consumer motherboards and not OEM ones.

 

[mirh]

Yes and no. Increasingly even gamer motherboards are getting locks and shackles (because swats of people loose their mind when even the most theoretical of the vulnerabilities is revealed).
On the other hand, just like you'd do on any crappy laptop I guess that tools like FPT or flashrom (or the bios recovery/flashback function) still allow you a certain reasonable leeway.

If any the question is if you couldn't actually get this to work the proper way with a vbios mod. I have seen many discussing about patched versions of NVflash, OMGVflash, nvflashk and whatnot.
Few of them seemed to care about pre-ampere cards (guess like enthusiasts aren't used to stick with more than 3-4 years old hardware), and of course even less people were curious about a BAR patch.
Which not only should have a lower bar to clear than most other hopeful hacks (like.. nvidia official patch for 3000 cards somehow operates on just a single bios region?), but even turing despite having many new godawful falcon restrictions should be now up for grabs. AFAIU you are only required a valid bios, not a signed one.