Extreme lag at Analyzing PCI Bus with Above 4G Decoding turned on

[syue87]

As you can probably see in the debug files, I have a very high end PC. I'm experiencing extreme lag/stuttering when loading HWiNFO64 at the Analyzing PCI Bus stage with Above 4G Decoding enabled. My mouse would only "jump" a few times a second, any YouTube video I'm playing would hang for a few seconds. With Above 4G Decoding enabled, It takes a few seconds to pass the Analyzing PCI Bus stage, but when I have it off, it's almost instant. With Above 4G Decoding enabled and Resizable Bar disabled, I'm also experiencing the lag.
Debug files for Above 4G Decoding enabled and disabled are attached.

 

[Martin]

Try to enable the "Low-level PCI Access" option in HWiNFO if that will make a difference.

 

[syue87]

Thanks for your reply. Yes, "Low-level PCI Access" reduced the lag from 5+ seconds to about 1 second, and the lag is not as bad, I can still see my mouse stuttering, but the YouTube videos would not hang. However, it's not the same as Above 4G Decoding disabled.
Do you have any insight on why this would happen? This doesn't seem to be a common issue. I've done hours of research, but I could find any solution. Any direction would be greatly appreciated.

 

[Martin]

Sorry, I don't know why is this happening. This is the first time I hear about such issue.

 

[syue87]

Just an update, I found the cause of this problem. It's caused by scanning the PCI bus when thunderbolt controller is sleeping. When I disable "Allow the computer to turn off this device to save power" for thunderbolt controller, I no longer have this problem.

 

[Martin]

That's an interesting observation! Thanks for sharing your finding.

 

[aethervisor]

OMG, I was having this issue whenever I booted Corsair iCUE. Although it does not do it after I reinstalled windows. But oddly enough, it was doing it when I was opening HWInfo64. The thunderbolt fixed the issue for me as well! I am running an 7950x with an Asus X670e Pro Art.

 

[Herkul]

Just an update, I found the cause of this problem. It's caused by scanning the PCI bus when thunderbolt controller is sleeping. When I disable "Allow the computer to turn off this device to save power" for thunderbolt controller, I no longer have this problem.

Thank you so much => one more OMG!

OMG, I was having this issue whenever I booted Corsair iCUE. Although it does not do it after I reinstalled windows. But oddly enough, it was doing it when I was opening HWInfo64. The thunderbolt fixed the issue for me as well! I am running an 7950x with an Asus X670e Pro Art.

I have also the same configuration 7950x with Asus X670e Pro Art since last year and I have already resigned myself with the fact that I will live with this annoying issue.

In my case only turning the thunderbolt off helped me. I had this problem in every similar software like CPU-Z or OCCT where a PCI Bus is being scanned at start. It did not disturbed me that it took much longer to start but rather than that the CPU freezed completely disturbed me really. At the beginning I thought even that something was wrong with the mainboard. Since the overclocked CPU performed very well in all other cases, I accepted this issue untill now.