Originally Posted by JackCY
I had some raised DPC with a 1060, which of course meant nothing to RMA personnel as they know squat nothing about these sort of things to even check it when explained. Luckily the driver was changed later so this issue went away.
About <150us, around 250us if click into a window = focus change. 100-150us is pretty normal even for many other heavy Windows parts.
The problem is when it starts peaking into 1000s = into "ms".
I would not bring Nvidia card to RMA for this particular reason. Its simply how the driver works, regardless its anything but optimal. However i did not had enough time to check all the settings in Nvidia panel to see if, and which one could be responsible.
Have seen cases where Nvidia driver was taking 4000 microseconds, eg. 4 miliseconds.
The impact isnt primarily in gaming - especially if you have a personal computer which is being used for only one task at a time. If your gaming PC also had to crunch some numbers on the background you might have significant penalty towards CPU oriented tasks, in case you are doing gaming and number crunching at the same time (databases, video encoding, whatever).
Hardware with high driver time does steal a bit of performance. Slower the CPU, higher the impact.
From my Buildlog (in signature) i have quite good experience with changing the parameters if Intels 211 LAN card. The Wifi card will cause longer driver operation, not just for itself, but also for related drivers such as TCPIP, Ndis, NetBT and of course ntoskrnl.
Imagine it rather as a chain, from which the slowest part is the determining factor = other parts of the system have to wait for the slowest one. In most cases that would be SSD (except NVMes), LAN card or something like TV Tuner. The more slow drivers, the higher cumulative effect.
Another impact might be in sound quality. If there are drivers or software which takes above 1ms to complete its ISR/DPC call, you might experience choppy sound. It would be more aparrent if you try to use sound card as a data transmitter and check the signal on the other side on "bit per bit" accurancy". For this purpose i used old 8bit PC which was originally used with audio tapes. In most cases it was not possible to play sound without any issues.
Bottomline is that i would not tell people to not buy Nvidias simply because of this behavior. I would not recommend to install nvidia card in a system which should be "clean" and work flawlessly or being oriented for both workstation and gaming at the same time, or to be used for audio/video purposes.