Testing please: GPU-Z Resizable BAR Support Report

1 : Anonymous2021/05/16 21:37 ID: ndynap

Based on the discussion in this thread I added a detailed PCIe ReBAR report to GPU-Z -> Advanced Tab, or just click on the Resizable BAR readout on main screen.



Not 100% sure yet if I got all these detections implemented correctly.

Could you guys test this on your systems (with and without BAR enabled/support) and let me know your thoughts?

2 : Anonymous2021/05/16 22:41 ID: gydl33c

The detection for the Resizable BAR BIOS and CSM options are incorrect:

Resizable BAR is enabled, and CSM is disabled.

NCVP reports "enabled" for Resizable BAR. GPU-Z's Graphics Card page also correctly reports Resizable BAR is enabled.

The other fields are reported correctly.


Ryzen 9 5950X

Asus Crosshair VIII Hero Wifi BIOS 3501 (AGESA

EVGA RTX 3090 FTW3 (w/Resize BAR BIOS)

ID: gyfoeoz

Build in first post updated, does it report CSM and BAR correctly now?

ID: gyhhhl3

It's mostly working now:

CSM disabled/Above 4G enabled/ReBAR enabled = ok

CSM disabled/Above 4G enabled/ReBAR disabled= ok

CSM disabled/Above 4G disabled/ReBAR disabled= ok

CSM enabled for UEFI only/Above 4G disabled/ReBAR disabled= reports CSM disabled

ID: gyeoxer

Same for me with Strix B450-F and 6700XT, win10 pro.

ID: gyfoev1

Build in first post updated, does it report CSM and BAR correctly now?

3 : Anonymous2021/05/17 01:13 ID: gye2zg6

Seems to work, although on my system CSM is supposedly still on, but BAR is working. I'm pretty sure I have CSM disabled, but I'll need to check to make sure. I also have Crosshair VIII Hero (non-wifi) BIOS 3501.

ID: gyfof4s

Build in first post updated, does it report CSM and BAR correctly now?

ID: gyhi9bq

This is what the original version showed:

This is with the BAR3 build, so seems fixed:

Oh, and that built-in screenshot function is nice. It even notified me of it when I tried to use windows own screenshot 🙂

4 : Anonymous2021/05/16 23:21 ID: gydprw7

Everything is "Yes" for me. Will try turning everything off and will edit this.

EDIT: Seems to be working properly for me, I changed those three settings in BIOS.

5 : Anonymous2021/05/17 03:09 ID: gyegq80

I have another system with an X570 and 6800XT, I'll check that tomorrow.


5600x Gigabyte X570 Aorus Elite Wifi - BIOS F33g (AGESA patch a) ASUS RTX 3080 TUF - flashed with new Resize BAR VBIOS

Doesn't detect "Resizable BAR enabled in BIOS" correctly.

ID: gyfofir

Build in first post updated, does it report CSM and BAR correctly now?

ID: gyfxo3q

Yes! All options show as Yes now, thank you.

6 : Anonymous2021/05/17 01:30 ID: gye4zgy

Seems to work just fine on my 5700XT system. Thanks W1zzard

ID: gyg0s0k

I have GPU hardware support disabled with my 5700XT setup tho.

Above 5g and Resizeable bar are correctly enabled + CSM is OFF.

I'm not sure that the 5700xt supports SAM.

7 : Anonymous2021/05/17 01:57 ID: gye83ep

Correctly detected RBAR/4G decoding and CSM either on or off.

ASUS Prime X470 Pro (AGESA V2 PI BIOS 5843)
5700 XT

8 : Anonymous2021/05/17 03:14 ID: gyehf41

Works fine with my GTX970 on Crosshair VIII Hero Wi-Fi

ID: gyf2z9q

Does the 970 support rbar or not?

9 : Anonymous2021/05/17 03:43 ID: gyel3v2

i7 10700F

Gigabyte z490 ud bios f20d

RX 6800 XT Midnight

Working fine for me. Correctly detected all changes I made in bios.

10 : Anonymous2021/05/17 04:12 ID: gyeogc3

Looks like it checks out properly and detects the right things as yes and no for me.

11 : Anonymous2021/05/17 04:15 ID: gyeoqzp

So mine reports that Above 4G Decode and Resizable BAR are disabled in the BIOS, which checks out because it does not seem to be enabled, even though I have Above 4G decode enabled and ReBAR on Auto. Gonna chalk this one up to a BIOS bug. I had it working on a previous BIOS for sure, not 100% sure when it broke.

Edit: Updating the BIOS to F33h fixed it, so now it shows enabled with all options as yes.

Edit 2: Somewhat unrelated, despite everything appearing to be working right, my performance in the Forza Horizon 4 benchmark seems way off what it was in the past.

12 : Anonymous2021/05/17 07:05 ID: gyf3318

Works on my system. All yes, 5800X, X470 Mainboard, 6800

13 : Anonymous2021/05/17 09:25 ID: gyfcoxb

Don't have ReBAR capable GPU but as CSM is off here is some details:

CSM detection is off, it says it is not disabled for me even though it really is.

Resizable BAR is set to Auto in BIOS but GPU-Z says it is disabled.


ASUS Prime X570-Pro, Ryzen R9 5950X, Quadro K4200

ID: gyfohm1

Build in first post updated, does it report CSM and BAR correctly now?

ID: gyfpi1b

Not reporting correctly yet, but keep up the good work!

14 : Anonymous2021/05/17 10:52 ID: gyfivdp

Looks to be working, on my Gigabyte B450 I Aurus Pro Wifi together with an R4650G and a Vega 56.

However I do wonder how things should be interpreted: I've got a everything but "GPU Hardware Support" and "Graphics Driver Support" showing "Yes", and the main GPU-Z page showing "Enabled".

Doesn't Resizable BAR also need the GPU Hardware, and Graphics Driver support to function? And if so, why does it say enabled.

If it doesn't need hardware and driver support, and indeed is enabled, what exactly is the difference between this and support for like the 6xxx series where there supposedly is both hardware and driver support?

I don't think this is necessarily something GPU-Z should be explaining, but this more elaborate (and better) presentation of Resizable BAR support also produces some questions of its own.

Thanks for the effort W1zzard!

ID: gyfozxp

If your motherboard / BIOS supports resizable BAR, and the GPU supports it too, the BAR should get resized automatically to VRAM size.

I verified this with B550 + 6900 XT + no driver installed in Windows

Obviously for performance benefits the graphics driver needs to be optimized for resized BAR. At this time, per-game, on both AMD and NVIDIA.

In their press briefings both confirmed that it's a per-game optimization, and I didn't get any "it could be universal" vibes, but they didn't touch on that point, probably both working on it behind the scenes. Current data by other reviewers and me confirms there's no gains for non-supported titles.

ID: gyfsdp9

Thank you! That completely clarifies it to me:)

15 : Anonymous2021/05/17 10:57 ID: gyfj9td

Asus Z590M-Plus Prime + Intel i5 11400F

CSM is disabled, but it's not reported as disabled (No).

ID: gyfuxbl

39.2 still reports CSM is disabled as (No) even if it's disabled.

ID: gyi2eom

BAR4 still does not fix the issue with CSM

16 : Anonymous2021/05/17 11:09 ID: gyfk81h

ASRock Fatal1ty B450 Gaming-ITX/ac AGESA + Ryzen 5 3600 + Radeon RX 6800

SAM is on and every read-out is correct as "yes".

17 : Anonymous2021/05/17 14:06 ID: gyg2pkp

Mine works 100%, all yes

18 : Anonymous2021/05/17 14:17 ID: gyg4af0

Here's my other system, using the newer GPUZ_BAR2: everything looks fine here

3600 MSI X570A-Pro - BIOS 7C37vHD2 (AGESA Reference 6800XT

19 : Anonymous2021/05/17 15:27 ID: gyge0yf

friend of mine says that his rebar is set to enabled in the bios, but its detected as 'disabled'

gigabyte + 9900k + 1080

ID: gygiyb0

GTX 1080 has no rebar support, so "rebar enabled in bios" shows as no, because there is nothing to enable.

any ideas how this could be reworded? i kinda like the "enabled in bios" wording because it helps make people aware that there is a bios option that they need to change.

ID: gygs6bt

how about “not applicable” or “feature not available” ?

ID: gygwfqe

I would say either remove them from the options if the GPU Support is (No), as if they can't be detected properly if there is no GPU support, they shouldn't really be shown.

Having them show as Undetectable or just blanked out could also work.

ID: gyh2znk

I changed the wording to be more precise in some cases than just yes/no.

Could you run it again on 1080?

ID: gyh6a4o

Hi Wizz, still have CSM Disabled = No, even though it's not enabled.
i5 11400F + Z590 Motherboard

ID: gyh6yoy

asked him. will post when he do.

meanwhile, here is mine

20 : Anonymous2021/05/17 18:16 ID: gyh2m48

ASUS ROG Zenith II Extreme Alpha TR 3960X Sapphire 6900 XT Nitro+

Shows "Enabled" for SAM and "Yes" for all requirements except disabled CSM, which shows "No".

21 : Anonymous2021/05/17 18:24 ID: gyh3sgp

I have tested this and ist working everything at Yes

5600x, RX 6800, ASUS B550M TUF PLUS, 32GB RAM

22 : Anonymous2021/05/17 20:27 ID: gyhl9jm

Works correctly for me. Detects Re-sizeable Bar is enabled and CSM is disabled.

23 : Anonymous2021/05/17 21:38 ID: gyhurco

Vega 56 on X570 Aorus Elite, 5800X

Everything detected correctly, correctly makes the distinction that while everything is enabled there is no GPU hardware support.

Edit: And for the record I think you've nailed it with the presentation of information

24 : Anonymous2021/05/17 23:09 ID: gyi6as7

Works on my system


x570 Aorus Elite (bios F33g) + 3900x + RX 6800XT (driver 21.5.2)

25 : Anonymous2021/05/17 11:49 ID: gyfnol5

Here is mine:

It says I have Resizable Bar OFF in the BIOS, but I have it on.

It says I have CSM Enabled, but I have it Disabled.

I'm using an Asus Rampage VI EXtreme X299 motherboard with a Core i9 10980XE. I have resizable bar working and enabled.

ID: gyfok4p

Build in first post updated, does it report CSM and BAR correctly now?

ID: gyfongp

It does indeed:


Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x