Here is a video with claims to performance increases:

It looked like an interesting fine, so I thought I was see if these settings would make any difference to MSFS 2024 SU2.

I posted this on Tom’s Hardware also:

I ran some ReBAR On/Off tests last night with MSFS 2024 and for all intense and purpose my FPS was the same (within 1 FPS margin of error). I performed the same flight and same location(LEIB) /aircraft/weather/etc. and graphics settings and recorded both with RTSS overlay. 

Test Hardware:
MSI X870E Godlike (rev. 7E48v1A34 … not latest UEFI but close) ReBAR enabled by default
nVidia 5090 OC Trio (PNY) (driver version 576.80)
2X48GB 6400Mts RAM
Samsung 9100 M.2 2TB

Test Software:
MSFS 2024 SU2 all graphics settings maxed out using SSAA (aka TAA=200), DLSS not enabled (no frame gen)

Confirmed ReBAR:
UEFI - Advanced - PCIe SubSystems - ReBAR enabled
GPU supported and enabled (HWINFO)
nVidia Inspector to set the 3 ReBAR values (both Global and specific to MSFS 2024)

I’ll post side-by-side video later (if we’re allowed to link videos not monetized?). 

In my case/settings ReBAR made no difference.  But, would like to know if anyone else found a benefit from this ReBAR setting?  Perhaps this works with other titles, so far I’ve only tested with MSFS 2024.

On a side note: There are some texture rendering issues with nVidia 5090 drivers that have not been addressed yet (with or without ReBAR enabled). On my AMD 9070XT and 7900XTX these texture rendering issues are NOT present. Seems to be related to Zoom level and LOD in MSFS 2024.  I have posted in MSFS 2024 official forums, but seems to be a nVidia driver issues since my AMD GPUs don’t have the same issue.

Rob.

 

 

3 hours ago, SayAgain said:

Here is a video with claims to performance increases:

It looked like an interesting fine, so I thought I was see if these settings would make any difference to MSFS 2024 SU2.

I posted this on Tom’s Hardware also:

I ran some ReBAR On/Off tests last night with MSFS 2024 and for all intense and purpose my FPS was the same (within 1 FPS margin of error). I performed the same flight and same location(LEIB) /aircraft/weather/etc. and graphics settings and recorded both with RTSS overlay. 

Test Hardware:
MSI X870E Godlike (rev. 7E48v1A34 … not latest UEFI but close) ReBAR enabled by default
nVidia 5090 OC Trio (PNY) (driver version 576.80)
2X48GB 6400Mts RAM
Samsung 9100 M.2 2TB

Test Software:
MSFS 2024 SU2 all graphics settings maxed out using SSAA (aka TAA=200), DLSS not enabled (no frame gen)

Confirmed ReBAR:
UEFI - Advanced - PCIe SubSystems - ReBAR enabled
GPU supported and enabled (HWINFO)
nVidia Inspector to set the 3 ReBAR values (both Global and specific to MSFS 2024)

I’ll post side-by-side video later (if we’re allowed to link videos not monetized?). 

In my case/settings ReBAR made no difference.  But, would like to know if anyone else found a benefit from this ReBAR setting?  Perhaps this works with other titles, so far I’ve only tested with MSFS 2024.

On a side note: There are some texture rendering issues with nVidia 5090 drivers that have not been addressed yet (with or without ReBAR enabled). On my AMD 9070XT and 7900XTX these texture rendering issues are NOT present. Seems to be related to Zoom level and LOD in MSFS 2024.  I have posted in MSFS 2024 official forums, but seems to be a nVidia driver issues since my AMD GPUs don’t have the same issue.

Rob.

 

 

I don't think you would notice any difference when running a 5090. But trust me, for my diminutive 3060, it makes a world of difference. So, horses for courses.

On 6/25/2025 at 11:24 AM, SierraHotel BSc said:

But trust me, for my diminutive 3060, it makes a world of difference.

Interesting, I wonder why?

2 hours ago, SayAgain said:

Interesting, I wonder why?

Maybe because it helps, along with the FG mod, to boost my FPS on high settings from 28/30 fps to 45/60 fps.................................

With my 3060Ti and Lossless Scaling FG, ReBAR only managed to get me a CTD. Maybe the combination of all that, MSFS2024 and the Fenix bird was too much for my 8 GB VRAM. I'll be getting a 5060Ti 16GB in a few days and I'll try again.

On 6/28/2025 at 12:34 AM, SierraHotel BSc said:

Maybe because it helps

I think you misunderstood, why is it helping … as in why would an older GPU work better with ReBAR?  Perhaps due to Frame Generation?  I don’t use and have not tested with Frame Generation.

On 7/1/2025 at 1:37 AM, SayAgain said:

I think you misunderstood, why is it helping … as in why would an older GPU work better with ReBAR?  Perhaps due to Frame Generation?  I don’t use and have not tested with Frame Generation.

Sorry, I thought you had already read the blurb on rBar and how it works, my bad. It's a good and educational read, by the way.

On 7/1/2025 at 2:37 AM, SayAgain said:

as in why would an older GPU work better with ReBAR

It is not about the age of the GPU, but about the performance of the GPU and the interplay of GPU and CPU. In short: with a 9950X3D and a 5090 you are at the very top end of hardware and as such, features that might improve interplay between GPU and CPU will not result in a huge performance increase. While it will, when you are in the mid to low tier range of CPU and GPU...

I do have some older GPUs and CPUs, will test ReBar (if supported).

AMD 9950X + AMD 7900XTX (software development, video/audio editing)

AMD 9950X3D + nVidia 3090 (render node for DaVinci Resolve, Topaz Video AI, and DVD/BD conversion)

AMD 5590X + AMD 9700XTX + nVidia 1080Ti  (render node for DaVinci Resolve)

Intel 12900K + nVidia 4070 Ti Super (Video AI and DVD/BD conversions)

Intel 7900X + nVidia 3060 Ti (video recording OBS)

AMD 9950X3D + nVidia 5090 (gaming)

It’s a little difficult with the 5090 as it has driver issues that present themselves as texture corruption that aren’t present in my AMD 7900XTX and 9700XT GPUs.  At first I thought it was an Asobo issue, but seems to be an nVidia issue.  ReBar can also cause texture corruption.

Rob.

And counter point:

Always good to have more than one perspective.

Rob.

6 hours ago, AnkH said:

features that might improve interplay between GPU and CPU will not result in a huge performance increase

I’ve only tested with MSFS 2024 in one configuration of settings and hardware, so I have no other data points.  There are several factors at play:

1.  nVidia drivers are problematic and continue to be problematic which adds to the variables.

2. Game settings can influence the performance increase or decrease.

In Matt’s video (above), he claims ReBAR is not applicable to AMD … this is false.

So as with all things “internet” (or word of mouth or print or websites or … ), the best place to determine benefits is to run your own qualified testing using a solid methodology.  Log data to file and avoid visual only sampling.

Anyone able to get REBAR activated on an old system like a Z170 MB with a 6700K cpu? I tried the method using the steps on GIThub and after loading the patched bios my system wouldn't boot - I had to clear CMOS to reload the old bios before patching.