DPC Latency Checker

[ReverendMaynard]

Alright, this is neither Win7-64 nor E760, gah... I am thinking it's either my keyboard or 5870 now.

out of curiosity zal, what B2B setting are you running and have you tried changing it from auto to say, 3, 4 5 or 6? Would be interested to see if it makes a difference.

[Musho]

Ok, this is my first run on this pc

Can anyone beat this guy?

[NapalmV5]

shenanigans^ dont count

high dpc latency: poorly configured system

light os only goes so far.. proper hardware settings do the rest

[justin.kerr]

rig in sig. Creative XFI fatality soundcard in there to. window 7, nothing disabled, modded, just a standard ol install of Win 7.

My Gigabyte X58a Ud3 is goes from 40-60, have not checked the other rigs.

[Raptor-X]

proper hardware settings do the rest

To which hardware settings have you found this metric to be the most sensitive ?

[NapalmV5]

thats for you guys to find out no?

everything from cpu clocks/settings to ram clocks/settings to the whole enchilada

[One_Hertz]

does CPU/ram instability increase latency? I am not in the mood for bsods right now so someone else check that out :P

[n!Cola]

thats for you guys to find out no?

everything from cpu clocks/settings to ram clocks/settings to the whole enchilada

Wow you are the man ! thanx for share

[zalbard]

out of curiosity zal, what B2B setting are you running and have you tried changing it from auto to say, 3, 4 5 or 6? Would be interested to see if it makes a difference.

It's set to 3. Haven't tried changing, I can I guess...

[mattkosem]

Pulling the USB drive that I had connected dropped the absolute max down to 154 and the average down to the double-digits. It seems pretty much anything is fair game.

--Matt

[Tiltevros]

new setup new results.

[Musho]

thats for you guys to find out no?

everything from cpu clocks/settings to ram clocks/settings to the whole enchilada

Uhm, as far as I know, forums (and communities in general) are about people helping each other, sharing knowledge and discussing things. You're asking people to reinvent the wheel, while you already seem to know quite a bit about bios settings affecting the latency? Pffff

[Computurd]

seems to me it is people using xeons and server OS. as a matter of fact the best rewsults are from that in two rigs^^^
the lanes on xeons are faster. they also have double the amount of lanes. the server os also takes advantage of that.

@musho +1

[NapalmV5]

your insults/rude comments towards me all go into a big black hole none ofem get to me sorry

[Gogeta]

All people so far with 100ish latencies are running Asus boards. Are you, by any chance, running an Asus board as well?

It was in my post. DFI board with a Xeon 3110.

I haven't taken the time to tweak out every single sub-timing and probably never will, especially when there is no noticeable difference outside a benchmark.

[NapalmV5]

full win7 ultimate (x86)
gigabyte ep45 extreme
q9650 @ 4.5ghz
ddr2 @ 600mhz
areca 1231
4x slc jmicron
24/7 stable settings
no ssd/registry tweaks

[SolidGoldstein]

In all seriousness, I have known about this tool for years. I heard about it in the context of pro recording DAWs. If your laptop has wifi enabled and Vista, it will probably shoot up above 1000 every few seconds. On an AMD Athlon64 PCI (socket 754) system I was lucky to get under 100. For some reason, this X58 system scores a little lower with my bluetooth adapter, eSATA external drive, USB flash, and Firewire sound interface plugged in and on.

[p331083]

My system has been suffering from audio/video stuttering ever since I upgraded to windows 7. Ive ran the latency checker and it shows me spiking all the way up to 70-80k, which is pretty bad.

Ive tried just about every solution I could think of; swap soundcard/videocard, update/try drivers for every device, go into device manager and disable every device I could, reinstall windows(premium/ultimate/betas), update mobo BIOS, use default bios settings, changing out memory etc. everything short of swapping out for a new motherboard(dont exactly have another i7 board on hand to try that). All the hours ive spent on the net say it can be any random driver/irq/device conflict so pin pointing it down to a single point is almost impossible.

Has anyone else every had an issue with DPC latency similar to mine?

system specs;
CPU - I7 920 @ 3700mhz
MOBO - DFI X58-T3eH8
RAM - OCZ 6GB PC3-12800 Flex EX
Video - EVGA GTX295
HDD - 300GB Raptor / 1TB Samsung F1

[Musho]

My system has been suffering from audio/video stuttering ever since I upgraded to windows 7. Ive ran the latency checker and it shows me spiking all the way up to 70-80k, which is pretty bad.

Ive tried just about every solution I could think of; swap soundcard/videocard, update/try drivers for every device, go into device manager and disable every device I could, reinstall windows(premium/ultimate/betas), update mobo BIOS, use default bios settings, changing out memory etc. everything short of swapping out for a new motherboard(dont exactly have another i7 board on hand to try that). All the hours ive spent on the net say it can be any random driver/irq/device conflict so pin pointing it down to a single point is almost impossible.

Has anyone else every had an issue with DPC latency similar to mine?

system specs;
CPU - I7 920 @ 3700mhz
MOBO - DFI X58-T3eH8
RAM - OCZ 6GB PC3-12800 Flex EX
Video - EVGA GTX295
HDD - 300GB Raptor / 1TB Samsung F1

Take out as many variables as possible. Run with just 1 stick of RAM, on stock settings. Detach your secondary hard drive and only use your primary one to boot into windows. Move your videocard to a different PCI-E slot. Detach any USB devices you don't need. (Wifi USB stick, storage USB, headset, printer, etc). Don't use anything else in your PCI and PCI-E slots. Now test again and report back what you're seeing.

And by the way, did you run the DPC Latency checker right after installing windows? Don't install any drivers or anything else. Run it right after you hit the desktop. If it's good, install drivers/attach devices one by one and keep checking if it comes back. That's the only way to pinpoint the problem. Good luck!

[Raptor-X]

Take out as many variables as possible. Run with just 1 stick of RAM, on stock settings. Detach your secondary hard drive and only use your primary one to boot into windows. Move your videocard to a different PCI-E slot. Detach any USB devices you don't need. (Wifi USB stick, storage USB, headset, printer, etc). Don't use anything else in your PCI and PCI-E slots. Now test again and report back what you're seeing.

And by the way, did you run the DPC Latency checker right after installing windows? Don't install any drivers or anything else. Run it right after you hit the desktop. If it's good, install drivers/attach devices one by one and keep checking if it comes back. That's the only way to pinpoint the problem. Good luck!

+1
& leave your network cable unplugged during this process. You do not want windows update to install drivers or patches for you in the middle of your trouble shooting..

[p331083]

Take out as many variables as possible. Run with just 1 stick of RAM, on stock settings. Detach your secondary hard drive and only use your primary one to boot into windows. Move your videocard to a different PCI-E slot. Detach any USB devices you don't need. (Wifi USB stick, storage USB, headset, printer, etc). Don't use anything else in your PCI and PCI-E slots. Now test again and report back what you're seeing.

And by the way, did you run the DPC Latency checker right after installing windows? Don't install any drivers or anything else. Run it right after you hit the desktop. If it's good, install drivers/attach devices one by one and keep checking if it comes back. That's the only way to pinpoint the problem. Good luck!

I did a fresh install of windows on my second harddrive and the first thing I did was fire up the checker and it still had the problem.

Either way Ive pin pointed the problem down to my cpu, as I was actually able to boot up into windows with no DPC issues by only running 2 cores and no HT, but I havent been able to reproduce it(saved the BIOS settings but they dont seem to work anymore). Changing the various cpu settings in the bios is the only thing that effects severity of the latency.

[SteveRo]

First thing I wuld think of is a driver - have you got latest drivers for everything?
Next, check the windows logs and look for any warnings or errors.

[SolidGoldstein]

I did a fresh install of windows on my second harddrive and the first thing I did was fire up the checker and it still had the problem.

Either way Ive pin pointed the problem down to my cpu, as I was actually able to boot up into windows with no DPC issues by only running 2 cores and no HT, but I havent been able to reproduce it(saved the BIOS settings but they dont seem to work anymore). Changing the various cpu settings in the bios is the only thing that effects severity of the latency.

Maybe Intel will replace under warranty with a 930

[zalbard]

I'll go ahead and revive the thread since I came up with some "fixes".

I owned EVGA X58 Classified E760, now I moved to Classified E762.
With pretty much bare bones fresh install and every single non-vital device disabled, I had 110-200 µs DPC Latency.
I kind of gave up on it for a while...
Recently, while being bored, I downloaded and installed LatencyMon to monitor DPC Latency. Quite a handy tool, which shows processes that create DPC delays.
So, the problem ended up being "ntoskrnl.exe" - Windows kernel (core)... Which means that no connected device is responsible, but the system itself.
So, I went into BIOS, and disabled pretty much everything I could.
Long story short: disable HPET (entirely) and disable C6 State (C3 and other ones are OK).
My DPC is now down to 10-14 µs. Occasional spikes to around 50-100 (thanks to HDD activity, I guess... I have not figured these out yet), but it's not a big deal as they happen every 10s-30s only.

Now the question is... Do all of you experience the same? Or is it EVGA's screw-up with BIOS, and enabling these does not cause higher DPC on other boards?
Feel free to leave feedback to show if it helped or not and how these settings affected your system.

I think it's also time to create a similar topic on EVGA forums, any volunteers?

[Computurd]

excellent work! i have a classy as well \

did anyone ever figure out exactly what the dpc latency is btw?