iozho wrote:
Nvidia still has to fix the high DPC latency.
well.. I know that drivers & apps ( nvidia specificly ) can rise your DPC latency - which is a "bug" state of these drivers/apps.
nontheless, the Windows itself is also part of the blam. ( i.e with win8 and above, on same HW, you won't necessary be getting this DCP latency problem )
I know the from win8 above such DCP latency issues from the HW ( I.E ACPI timers ) were solve by the OS itself.
but with win7.... things not so great.
please see the following link: HERE to diagnose simply the issue...
I know today that any such "simple" DPC diagnostic tools does NOT provides the best real/correct info ( at least for win8 and above )- as only windows diagnostic tools ( some sdk ) is the nearest to the "truth".
As a quick fix - please try to use the following: TIMERTOOL to lower your DPC Latency.
As an interesting anecdote, the following provided:
I know that using such tools on my retired Asus G55VW with win8 x64 did not help to get better FPS, as it is a problem with how win8 and above are built ( using this tool actually lowered FPS in "PCMark Vantage" benchmark app ).
I know this, cause I tested it myself with some scientifically technique called "factorial design" - The idea in short is that you perform about 1/10 tests then what you really should do - but from these small quantity but well planned repetitions, you can get results that statistically speaking are precise 99.5% like doing in addition the hole other 9/10 tests.
The DPC latency "fixer" app I used back then was timer-resolution.
I wanted to check the weight effect of DPC Latency fixer app (timer-resolution) on FPS.
As the report was not written fully in English I provide only some of the results:
The test planning:
The results:
The the results:
you can see the the coefficients before "timerResolution" is much smaller then resolution it-self.
Thus don't think that "fixing" DPC latency fixer apps will help you gain a lot of FPS, if at all 🙂
Gps3dx wrote:
well.. I know that drivers & apps ( nvidia specificly ) can rise your DPC latency - which is a "bug" state of these drivers/apps.
nontheless, the Windows itself is also part of the blam. ( i.e with win8 and above, on same HW, you won't necessary be getting this DCP latency problem )
I know the from win8 above such DCP latency issues from the HW ( I.E ACPI timers ) were solve by the OS itself.
but with win7.... things not so great.
please see the following link: HERE to diagnose simply the issue...
I know today that any such "simple" DPC diagnostic tools does NOT provides the best real/correct info ( at least for win8 and above )- as only windows diagnostic tools ( some sdk ) is the nearest to the "truth".
As a quick fix - please try to use the following: TIMERTOOL to lower your DPC Latency.
As an interesting anecdote, the following provided:
I know that using such tools on my retired Asus G55VW with win8 x64 did not help to get better FPS, as it is a problem with how win8 and above are built ( using this tool actually lowered FPS in "PCMark Vantage" benchmark app ).
I know this, cause I tested it myself with some scientifically technique called "factorial design" - The idea in short is that you perform about 1/10 tests then what you really should do - but from these small quantity but well planned repetitions, you can get results that statistically speaking are precise 99.5% like doing in addition the hole other 9/10 tests.
The DPC latency "fixer" app I used back then was timer-resolution.
I wanted to check the weight effect of DPC Latency fixer app (timer-resolution) on FPS.
As the report was not written fully in English I provide only some of the results:
The test planning:
The results:
The the results:
you can see the the coefficients before "timerResolution" is much smaller then resolution it-self.
Thus don't think that "fixing" DPC latency fixer apps will help you gain a lot of FPS, if at all 🙂
I've already profiled the system and used the tools above all of them had random usefulness. The tools itself sometimes cause DPC delays. I tried the timer fix but as I was suspected that did not help since the problem is that we spend too much time in interrupt context. With the newest Nvidia driver things are horrible - running carvisualizer.plus360degrees.com made DPC to go over 1000micro seconds. So far things are much better with the old driver - I rarely see spikes above 1000. Win7 might be part of the problem but why old driver works sort of ok while the new driver brings the whole system under heavy DPC latency? I still believe Nvidia has work to do and it would be nice if they test before releasing or incorporate better QA process.
