Dell Precision 5820 Resizable BAR support. Dell needs to update the BIOS!

We tried reaching you on a private message asking for the Service Tag number to ascertain the warranty but did not receive a response. Please feel free to reply to the private message whenever you are available.

Any progress please ? We have more than 30 pcs of Dell 5820 Workstations and we need "Resizable BAR Support" for main application. Without Resizable BAR Support is application very limited.

Dell every time redirects this communication to private messages. And in private message "recommends to enable Resizable BAR in BIOS". Regardless of the fact that in the very first message you write to them that this function is not found in the bios.

@DELL-Cares​ hi do we have a solution for the bios option ? we need it for intel arc 770.

I also need an option to enable resizable BAR. 

I too have same problem im getting ready to buy intel arc a770 for my dell precision T5820 and I'm finding it hard to find any information or a solution before I buy this gpu

Got a Precision 5820 Tower but no REBAR support in bios. Intel's Arc A770 needs REBAR to function properly. Would be very helpful with either a official update in BIOS or .bin file so we can patch in REBAR support ourselves!

I dumped my perfectly servicable 5820s because of this issue. If Dell won't maintain their products then I'll find a company that will.

This is not a consumer grade piece of hardware, @DELL-Cares It's a Commercial/Industrial Workstation that has to meet the demands of Data Scientists and Engineers. If you're not going to let us use modern GPUs to their full capacity in them, then come out and say it.

I installed the latest BIOS, Precision_5820_2.39.0.exe, dated Dec 17, 2024.

Still there is no REBAR support in the options.

Give us the actual BIOS files, not the exe, so we can patch it ourselves!

GitHub - xCuri0/ReBarUEFI: Resizable BAR for (almost) any UEFI system

The only missing piece to the puzzle is "Resizable BAR enabled in BIOS".

That's sad.

Febuary 2025 and still no support for rebar in bios.

I was actually considering company wide upgrades to 5860's and 7875's and for the first time purchasing first hand instead of secondary market as we have since our first 670! This single issue has forced a re-evaluation of that idea and possibly the brand overall since it's possibly not as future proof as it has been known for. Honestly, just keeping our 5810's would have been better at this point, since the 2 remaining ones keep pace with this model.

If anyone has any ideas on how to recompile the bios exe for installation, I have the current 2.42.0 extracted and modified with a dxe to enable rebar support.

I have just figured it out, and rebar works great (bar1 is 16 gigs now). But unfortunately, this works through a potential vector of attack for dell systems via the bios exe, so I cannot share the solution. It's best that they just release a bios update themselves so that nobody else discovers this vulnerability.

I just installed BIOS 2.43.0 released Jun 15 2025. Still no rebar. I have the xeon model.
I am having a hard time understanding why not. xCuri0 in his spare time has created a means of patching BIOS files with rebar support. ReBarUEFI on GitHub.
If it is a feature than can be added to the BIOS, why hasn't it been added. It seems it is only on low level motherboards that this feature is not included. The manufacture date on my T5280 is 07-06-2023. About 2 years old. When I purchased it, I did not consider it a low level computer and the price was definitely not low level.
I ordered an intel arc a770 on ebay with a no return policy, so am forced to make it work somehow. I am retired and living on a fix income, so this was a big ticket purchase for me. I can't afford purchasing another video card that doesn't require rebar.  I did not even know rebar was a thing, until I started researching Linux drivers while waiting for delivery. Intel arc requires rebar on Windows too, so please don't side step with we don't support Linux.
On GitHub 2 people have claimed to get the rebar patch to work on T5810 and tekbred on this thread has claimed to get rebar working.
I really don't like the idea of a patched BIOS, that could possibly brick my computer. These low end motherboards don't have dual BIOS.
Has anyone made rebar work and want to share their method?

@roy555555​ Sorry, T5820