[Feature Request] Set Message-Signaled Interrupts

[DonnerPartyOf1]

Requesting ability to enable message-signaled interrupts on GPU and related devices (sound, USB-C) after driver installation is complete.

On each driver install, Nvidia resets a registry key which disables MSI and forces devices to fall back to legacy INTx mode, presumably for compatibility reasons with their old nForce motherboards which are infamous for having a completely broken MSI implementation. INTx mode can result in longer deferred procedure calls and interrupt handling, which manifest as latency-related issues such as audio popping or unexplained dropped frames. These problems are commonly experienced in virtualized environments and on systems with overburdened PCIe lanes.

On modern motherboards and graphics cards, there is rarely ever a reason to turn off MSI.

More reading, and a technical reference.

Intel paper on MSI

Best regards.

 

[R-T-B]

I do this every driver install, so would be helpful.

 

[Ed_1]

Added tweak to enable Message Signaled Interrupts version 1.30

Nice!

 

[duk6046]

This tweak is need a clean install?

 

[W1zzard]

This tweak is need a clean install?

Grab today's v1.4.0, it fixes a bug in the MSI tweak implementation.

A clean install is not needed, but you have to either reboot or restart the graphics driver

You can verify if MSI is enabled by going to Device Manager -> Properties of your graphics card

This screenshots shows classic interrupts enabled (INT 16). Once MSI is enabled, this will become a negative number

 

[Ed_1]

Didn't try 1.4.0 but test beta you sent is working fine, played many hrs of BFV, all good.

BTW I have never "removed" drivers prior to updating them, I just chose "clean install" always in install option.
As posted above any MSI mode changes need a reboot

 

[duk6046]

it seems that was not been applied, i'll try again with v1.4.0. Thanks

Added) v1.4.0 is work fine without clean install.

 

[Bronan]

Works like charm reinstalled the previous driver because my game started crashing almost every 5 minutes (modded Skyrim SE)
Choose todo the most clean install without all the unneeded crap and spyware and it got done just by selecting express install.
So simple that you can install any version you want, i love it

 

[shaolin95]

Hey guys so I only have one PCI device not using MSI..."hd audio enumerator bus driver". I am guessing is better to leave that one as is?
Thanks

 

[ochevidnost]

It seems you still need to switch drivers to MSI mode. NVCleanstall only adds support for it?

Also devices in MSI mode do not use usual IRQ's:

 

[R-T-B]

It seems you still need to switch drivers to MSI mode. NVCleanstall only adds support for it?

View attachment 162350

Also devices in MSI mode do not use usual IRQ's:

View attachment 162351

It only applies it to the GPU. As for not using normal IRQs... that's what MSI mode does.

 

[W1zzard]

NVCleanstall only adds support for it?

NVCleanstall will only change the GPU MSI setting, not HDA device

 

[ochevidnost]

I'm not talking about HDA device.
Although NVCleanstall adds GPU MSI setting, device still works in default mode because nvidia driver reset it.
You still need to switch GPU to MSI mode after this, you can check for yourself.
There is open source utility to check & switch MSI setting.

CHEF-KOCH/MSI-utility

A script/tool which tries to improve Windows latencies - CHEF-KOCH/MSI-utility

github.com

 

[Tiki Thorsen]

I'm not talking about HDA device.
Although NVCleanstall adds GPU MSI setting, device still works in default mode because nvidia driver reset it.
You still need to switch GPU to MSI mode after this, you can check for yourself.
There is open source utility to check & switch MSI setting.

CHEF-KOCH/MSI-utility

A script/tool which tries to improve Windows latencies - CHEF-KOCH/MSI-utility

github.com

The GitHub page not working, error 404.

 

[trparky]

The GitHub page not working, error 404.

I saw this too.

 

[Tiki Thorsen]

I attached the file that I downloaded a month ago or so from the GitHub page, in case someone needs it.

 

[Solaris17]

Thats v2.


Attached is the v3 version of that app.

 

[Tiki Thorsen]

Thats v2.


Attached is the v3 version of that app.

Oh, even better, thank you!

 

[Coldblackice]

So what's the consensus on which, if any, devices should be set to "High" priority?

And what might be any noticeable effects for something being set as "High" priority vs. undefined? In a best-case/worst-case scenarios, if necessary.

 

[Chipscout]

Hi. Thank you for this utility.

Nvidia resets a registry key which disables MSI and forces devices to fall back to legacy INTx mode, presumably for compatibility reasons with their old nForce motherboards which are infamous for having a completely broken MSI implementation.

hmm, what about motherboard on nforce 700, should i to use this fix\switch GPU to MSI mode ?

 

[trparky]

What I want to know is how the heck are there still old nForce motherboards out there?

 

[R-T-B]

What I want to know is how the heck are there still old nForce motherboards out there?

They didn't die and someone is using them? Heck there are still 486 based systems out there man (just not many online)

 

[THU31]

This seems to have fixed my problem with presentation glitches during video playback with madVR. I have had that problem since I switched from a GTX 1080 to an RTX 2070 SUPER. Just random presentation glitches which looked like skipped frames.

After doing this, I watched videos for over two hours and it was perfect. If this really is fixed, then it is an early Christmas for me!


Does it make sense to switch the priority from undefined to high for the GPU/HD Audio Controller?

 

[W1zzard]

Although NVCleanstall adds GPU MSI setting, device still works in default mode because nvidia driver reset it.

Which card? I tried to repro this on 3060 Ti with latest drivers and MSI was already enabled.

 

[THU31]

For me the GPU is always in MSI mode automatically after installing the driver with this tweak.

Only the HD Audio Controller defaults to LineBased.