Opened Ticket NVidia MSI Mode Desktop Cards

So I opened a ticket on Nvidia live chat about MSI Mode not enabled for Desktop card but for Mobile Laptop ones and I want them to fix this issue.


to compare it on my laptop the nvlddmkm.sys file doesn't ever jump the same like on the desktop, it is never the highest DPC routine execution time.

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Let's hope they might do something with it.

 

I use to check this and I use to force MSI mode on my nvidia cards. And I have zero difference between MSI and IRQ when comes to DPC routines, both modes have same numbers, it was like that with my old x58 build and now my z170 build.

 

You can enable it manually if you want to (see http://forums.guru3d.com/showthread.php?t=378044), but it doesn't really affect much DPC either way. Oftentimes DPC issues are caused by a combination of hardware or drivers, and not by a single component on its own.

Its honestly one of those myths that keep being repeated by people without a clear understanding of what it really does.

 

I've had crashes happen after enabling that mode, I'd just leave it alone until nvidia deems it ready officially. YMMV.

 

Interestingly they've switched to MSI mode for their audio drivers (@ManuelG posted that here as well), however he did not seem to know that MSI isn't enabled for desktop GPUs.

Maybe he can elaborate the reasons behind that?

 

They didnt enable anything . In alll dekstops they use legacy mode.

 

nope, hd audio drivers are in MSI mode by default

 

Apparently desktop cards are different as if you check NV CPL system info it says "IRQ: not used".

Like tsunami said there isn't really a difference between legacy and MSI mode and MSI mode may cause issues like lucidus said.

I've had the same experience personally, no benefit from switching to MSI with a desktop card (applies to all Maxwell and newer GPUs I assume, ie. all that report IRQ as not used).

 

That's because the Dev/Driver needs to support it and add the registry but also know how to work with it.

That's why I opened a ticket to nvidia so they will support it official. Adding/Selecting MSI Mode from the little program doesn't really add or change the MSI Mode . because the driver can't communicate correctly with the driver.

Also it's funny why Sound Cards can't support MSI Mode yet... Creative, Asus, no one add MSI Mode. we need to change this as it might fix many issues we were always having.

Can't see what so special on Nvidia GPU laptops or AMD/ATI Desktop cards, that Nvidia can't support MSI Mode on the Desktop.

 

If IRQ changes from positive number to negative one (in Device manager for example) then card and drivers work in MSI mode.

???

And once again - MSI mode has nothing to do with DPC. MSI mode is about ISR. DPC is scheduled from the ISR in the same way regardless of MSI or Legacy mode.

 

It changes, but crashing and stability issues are not the way to go when it says it's right.

You can also do it for the sound card but you will have crashes,stuttering, crackling and many other issues. Also USB3 is always MSI, but you cannot change USB2 to MSI no matter what you do.

Also if you try to change the Microsoft SATA Controller without Intel/AMD/Nvidia SATA Controller driver than your windows will not boot, means it needs a DRIVER to support this function even though windows say it's active, but it will not work properly. If you want to see what's visible that's fine, but look on the comments before, people said already when they enabled a Non MSI supported hardware they had issues, even when it said it's "working" from windows device manager.

 

Only for some users. Only two users reported issues. I never had crushes from switching devices to MSI mode.

Realtek cards work in MSI mode. Some users reported not working Creative cards (no crushes though).

In Windows 10 SATA drivers from MS work in MSI mode by default.

After all nobody forces anybody to do the tweaks. And it`s not like the tweak is irreversible.

I am curious what NVidia will do on your ticket (and whether). So please inform us on updates.

 

If its crashing from changing interrupt modes, then something like chipset drivers or the pci-e express controller from the cpu might need updating, reinstalling. If you switch it, it either works and brings the picture back, or would be stuck on a black screen if it couldn't initialize.

If you are referring to the sound device from your graphics card, then same as above would apply.

This depends on the hardware in question as older onboard SATA controller's (like nvidia's nForce MCP) might not switch over to MSI mode and you would then have to system restore to fix it (regardless, always back up your data if you experiment with storage controller interrupt modes). Yes, Windows will recognize the registry key for MSI mode and the driver can recognize it too, but then not be able to infer functions through that mode.

Well unsupported does mean unsupported... What did they think would happen?

mbk1969 made a thread about MSI a while back Windows: Line-Based vs. Message Signaled-Based Interrupts

 

that "IRQ : not used" is bug they never fixed in the NVCP if you look in the device manager it is using a IRQ,

Seeing as I dont install there audio drivers for there card the drivers for my card audio are still using IRQ

 

Yeah Dev. Manager shows IRQ, wasn't aware NVCPL was bugged in that respect though, thanks.

Btw one could benefit from switching the GPU to MSI mode if the default legacy IRQ is shared with another device. Simply as this "forces" the GPU to use a different IRQ.

To be clear I never had any issues running GPU in MSI mode. Saw no practical benefit from it but that doesn't mean it couldn't be beneficial in some cases.

 

I've been running mine in IRQ mode for years. It was sharing the same IRQ with the USB host controller. About 4 months ago, I switched to MSI mode (I re-apply the tweak after every driver upgrade and verify in device manager.)

There is exactly zero difference. I keep doing it simply "just because", but not a single thing got better nor worse. Same DPC latency, same performance, same everything.

It's worth noting that this is for the Windows driver. The Linux driver (I dual boot) is using MSI by default.

 

That audio chip is just a realtek afaik. Both it and my motherboard's realtek driver (a recent build) are using legacy mode (+). I can enable MSI mode with no issues at all for audio though.

I don't remember which driver exactly but closer to the creator's update's release, MSI mode had issues with the display driver. There weren't issues prior. Forza 3 would crash every 10-15 minutes. Even recently I had a nvkdlmwhatever.dll bsod in the lock screen after I enabled it.

 

Nvidia GPU use realtek Audio chips? and nivida make there own custom drivers? Not sure how feel about that.

my realtek drivers are runing in IRQ mode the MOBO are on IRQ 17 and HD Audio on the GPU is IRQ 16 which is same as GPU IRQ. USE to force MSI on the GPU just so there was no sharing of IRQ but, I never saw any difference and still dont so dont bother

I using Modifyed verison of Realteks (v7614) with DDL enabled I refuse to change Realtek audio drivers due to the 5 year long issue i had with my old system hardlocking do to realteks drivers have issue and not likeing HW accleration.

 

I've noticed the same. I see no observable difference toggling MSI mode in Windows, but in Linux on this machine MSI is enabled by default. Of course I've never forced IRQ mode in Linux to see if there's a difference or not as a comparison there either.

Regardless, that it defaults to MSI in Linux but IRQ in Windows would appear to indicate that there's either a problem with Windows, or a problem with Nvidia's Windows drivers.

 

Or a problem with the Linux drivers in IRQ mode. Don't be biased