EXPERIMENTAL: Resizable BAR in DCS for NVIDIA RTX 30 Series GPUs

[YooK]

Hi,

It seems there is 18 profiles now, not 17, I just downloaded the latest Nv drivers 466.27, also I just downloaded nvinspector 2.3.0.10

I spent last night figthing with my computer since my updated ASus Z390-E Beta BIOS didnt want to boot or show anything on the monitor (turns out after updating the Bios, I forgot to go back to default settings before restarting and that created a mess... I had to clear cmos and load fail safe but that took me a while to figure out...) Im also glad I saved the Bios Profile to a USB key so I didn't have to redo my OC entirely from scratch...

 

I also had to convert my M2.NVME boot disk that was on MBR (Master Boot Record) to GPT (GUID Partition Table) using this guide: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

Otherwise Rebar won't be able to activate if Windows and Bios aren't booting in UEFI mode.

 

Even if Rebar turns out to be placebo I'm glad I did that because the UEFI startup sequence is much faster and nicer !

Now everything is ready and Rebar is activated.

I hope the long and tedious fight was worth it  Will be back for feedback !

 

Advise: if you're not familiar with BIOS and Firmware updates, you have no clue what is UEFI or GUID, I wouldn't tryhard for activating REBAR or you might end up with a dead computer. But if you want to give it a try follow the guides thoroughly and the tips here and there that I just gave.

Edited May 7, 2021 by YooK
drivers & nvi versions

[ShaunX]

4 minutes ago, YooK said:

Hi,

It seems there is 18 profiles now, not 17, I just downloaded the latest Nv drivers as I kept 456.98 so far for G9 purposes... also I just downloaded nvinspector.

I spent last night figthing with my computer since my updated ASus Z390-E Beta BIOS didnt want to boot or show anything on the monitor (turns out after updating the Bios, I forgot to go back to default settings before restarting and that created a mess... I had to clear cmos and load fail safe but that took me a while to figure out...) Im also glad I saved the Bios Profile to a USB key so I didn't have to redo my OC entirely from scratch...

I also had to convert my M2.NVME boot disk that was on MBR (Master Boot Record) to GPT (GUID Partition Table) using this guide: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

Otherwise Rebar won't activate if it's not in the UEFI mode.

Even if Rebar turns out to be placebo I'm glad I did that because the UEFI startup sequence is much faster and nicer !

Now everything is ready and Rebar is activated.

I hope the long and tedious fight was worth it  Will be back for feedback !

 

 

Your signiture suggests you have an RTX2080 which won't support resizable bar. Perhaps the sig is just out of date ?

[YooK]

13 minutes ago, ShaunX said:

 

Your signiture suggests you have an RTX2080 which won't support resizable bar. Perhaps the sig is just out of date ?

Yes I got a 3080 FE. I dont even see my sig. let me update that  there, better

Edited May 7, 2021 by YooK
update sig

[unltd]

Enabled   I have finally coerced my G2 into working smoothly between a combination of witch hexes, sacrifices, straight up cpu beatings.  But thanks for this one.  

[Oceandar]

I just enabled resizable bar on my 3060 ti and I think I've got nice improvement and much more fluid. Gained 5 - 7 fps more but I also noticed higher CPU load from 20 to 23 % ? Cant complain.... it was like free upgrade anyway.

R5 3600, RTX 3060 Ti, MSI 550M Bazooka. RAM 32Gb 3200 Mhz. Latest Win10, Bios and driver, DCS Open Beta. Flat Screen.

[Sysrek]

I am no longer seeing the entries. Did the recent Nvidia driver update remove them?

[zildac]

They're still there for me:

 

[Hoirtel]

1 hour ago, Sysrek said:

I am no longer seeing the entries. Did the recent Nvidia driver update remove them?

Have you clicked the "show unknown values" button. Caught me out once. I've just updated to latest driver and they are there for me.

[Sysrek]

17 hours ago, Hoirtel said:

Have you clicked the "show unknown values" button. Caught me out once. I've just updated to latest driver and they are there for me.

Yup I double checked and it was clicked show unknown values.

 

EDIT: So I reinstalled the latest drivers and they are now showing. So strange.

Edited June 7, 2021 by Sysrek

[unltd]

Just as a reminder.  You need to reapply the changes after a driver update.

[jurinko]

I have a feeling it does not work anymore. I will revert to previous driver and test. 

 

Edit: confirmed ReBAR does not function in DCS with the newest driver when activated as before via three lines in NVPI. Reverting to driver from 30.3. restores game smoothness a lot.

Edited June 27, 2021 by jurinko

[DavePastry]

how did you confirm whether it was or wasn't working? 

[Hoirtel]

I had a feeling it wasn't as smooth with the new driver, despite me enabling it again. I'll revert and see as it really did help smooth things out.

 

EDIT: I too have now rolled back to previous driver and have regained the smoother performance I had previously. I hope this is just a quirk of the new driver and not a lockdown of the rebar functionality otherwise I will  never be able to update the GPU driver. It really reduces ground stutter in low level flight for me. Thanks to @jurinko for pointing this out.

Edited July 2, 2021 by Hoirtel

[Hoirtel]

On 6/28/2021 at 9:16 PM, DavePastry said:

how did you confirm whether it was or wasn't working? 

The proper way is to measure frametimes... However I have a Syria F16 Incirlik take off and low city flight as trackfile which I do all my tuning to. With rebar disabled I get continuous ground stutters when looking down, with it enabled its almost clean. I have run a few tests enabled and disabled and its completely repeatable every time. This is all VR btw.

[RealDCSpilot]

Something definitely changed with the latest driver update or DCS updates. I'm getting performance degradation too, but still hesitating switching back to the previous driver.

[RealDCSpilot]

Okay, just switched back to 466.77, re-enabled resizeable bar and smoothness came back again. There is definitely something wrong with the latest driver. It's not directly measurable in frametime or fps, it's more that image studdering and warping through motion smoothing goes bonkers. I think it's more of a problem of Nvidia driver and SteamVR interaction...

Edited July 3, 2021 by RealDCSpilot

[speed-of-heat]

Is it a “bug” or a feature… the reason I ask is nvidia has a habit of closing these technical loopholes..l

[Hoirtel]

12 minutes ago, speed-of-heat said:

Is it a “bug” or a feature… the reason I ask is nvidia has a habit of closing these technical loopholes..l

This is my concern. Well I guess I can stick with the driver I have now for a while at least.... Considering this loop hole did/does exist maybe it's not too difficult for ED to incorporate it properly in a future engine update. 

[zildac]

10 hours ago, Hoirtel said:

This is my concern. Well I guess I can stick with the driver I have now for a while at least.... Considering this loop hole did/does exist maybe it's not too difficult for ED to incorporate it properly in a future engine update. 

Would be great, but that would also involve ED submitting to Nvidia for "certification" and I'm not sure that would (unfortuantely) happen. No idea what the criteria are to get "Rebar Ready - TM" by Nvidia either.

[Hoirtel]

21 hours ago, zildac said:

Would be great, but that would also involve ED submitting to Nvidia for "certification" and I'm not sure that would (unfortuantely) happen. No idea what the criteria are to get "Rebar Ready - TM" by Nvidia either.

Reading that it seems likely that rebar was locked down by Nvidia on this last driver. Oh well looks like I won't be able to update it for quite a while. Hmm. 

Edited July 4, 2021 by Hoirtel

[speed-of-heat]

they are consistent... this is exactly what they have done every single time a new feature gets hacked by the community i cant honestly blame them for it 

[ShaunX]

Having started this thread I'm still not convinced I ever saw any performance benefit personally.

 

Shame for those who did though, particularly coinciding with the Marianas release, though I guess they can always revert to previous version for now.

[FupDuck]

Hey! Just curious if anyone has tried this recently. I just got a 3070 and turned on rebar, but I was wondering if it works for DCS again with the latest drivers. Thanks! 

[speed-of-heat]

Resizable BAR

I wanted to redo some of the Rebar testing  and I have installed the Release version of my BIOS, previous testing was done with a beta BIOS:

 

		Frametime in ms		Delta From Baseline
Test	Baseline	GPU	CPU	GPU	CPU	Changes
82	Test 75	9.52	8.55			Average for Baseline 2.7.6, FSR1.1, Windows 11, Hotfix Shaders
87	Test 82	9.67	8.54	-0.15	0.01	Rebar Off Test 1
88	Test 82	9.48	8.43	0.04	0.13	Rebar Off Test 2
89	Test 82	9.62	8.60	-0.10	-0.05	Rebar Off Test 3
90	Test 82	9.59	8.52	-0.07	0.03	Rebar OFF Average
91	Test 82	9.60	8.27	-0.09	0.28	Rebar On Test 1
92	Test 82	9.59	8.30	-0.07	0.25	Rebar On Test 2
93	Test 82	9.50	8.35	0.01	0.20	Rebar On Test 3
94	Test 82	9.56	8.30	-0.05	0.25	Rebar ON Average

 

As you can see on the z370 chip set it enabling Rebar has a small performance improvement on , so I now leave it turned On, but either way its pretty close to margin of error.

 

I should add that is without any “hack” of the driver… just the difference between it being on and off athe firmware level
 

Edited October 7, 2021 by speed-of-heat

[FupDuck]

Hey thanks Heat. Did you redo the test as part of your Sept 26 update? 

 

Also, did you just turn rebar on in the Nvidia settings? Or did you also do the steps mentioned in the first part of this thread to "enable" it for DCS using the profile inspector?  

 

Thanks once again!