P35 Motherboards and DPC Latency Spiking

[theearbox]

Re: P35 Motherboards and DPC Latency Spiking

I wrote time ago, I thought that my dpc latency problems were fixed with nvidia drivers but I was wrong, they only improve the problem but not fixed it.
I discovered a possibly problem that could affect dpc latency: PCI Express x1 Bug, you can read about it here this page shows a way to fix it but it did not work in my gigabyte mb (ga-ep35c-ds3r)

[clarsax]

Re: P35 Motherboards and DPC Latency Spiking

I have been noticing occasional audio drop-outs using the on-board audio on my EP35C-DS3R rev.2.1 motherboard. Other components include Intel E8400 CPU, Corsair TWIN2X4096-8500C5DF G RAM, and EVGA e-GeForce 8800 GT Superclocked 512 MB, PCI-2 video.

I orignally built the computer on Windows XP SP2, then upgraded to SP3. I do not remember having the audio problems until I upgraded, but maybe I am using my computer audio more frequently now and do notice the problem frequently. Gigabyte's technical service department response to my inquiries is to revert to XP SP2.

Has anyone who has had this problem actually fixed it by going back to the earlier OS version?

Thanks.

[weckker]

Re: P35 Motherboards and DPC Latency Spiking

I've installed the latest bios version (F13 -on my DS3R system and F9 on my DS3L one) and all seems to be going well for over a month now. No spikes no matter if I use EIST feature or not. On my DS3R i have Win7 RC x64 and on the other one I have Win XP Pro SP3 x86.
Hope this helps someone.
Best regards!

[clarsax]

Re: P35 Motherboards and DPC Latency Spiking

Hi weckker,

You indicated that you have the GA-P35-DS3R (rev2.1) motherboard, while I have the GA-EP35C-DS3R (rev2.1) motherboard. The two boards seem to be running two different series of BIOS updates with your version at F13 and mine at F4.

According to the thread at GA-EP35-DS3R vs GA-P35-DS3R - [H]ard|Forum the two boards should be the same. Do you know that the BIOS from one series can be used for the other?

I also see that you are running Win 7 RC x64 on your DS3R board. Has the latency problem not been an issue with the DS3R series as it has been implied to be an issue with Win XP SP3?

Thanks.

[clarsax]

Re: P35 Motherboards and DPC Latency Spiking

Update --
Noted that I was in BIOS version F4a for the EP35C-DS3R motherboard. Turns out that was a beta version of the most recent update.
I installed the final version of the F4 BIOS, and, so far, no warbling.

I hope this lasts.

[weckker]

Re: P35 Motherboards and DPC Latency Spiking

Hi clarsax
Happy to see things are going on well for you.
On my DS34 board I never had running Win XP SP3 only XP SP2 (both x86 and x64 with high latency spikes), then Vista x64 (acceptable latency spikes) and now Win7 (no spikes at all). I don't know if the bios or the windows upgrade made it work for me because I haven't checked it with DPC after installing Win7, only after the bios update (I updated the bios after installing Win7), so I can't be sure which one did the trick. Maybe both of them :D

ps: I don't think a p35-ds3r bios will work on an ep35-ds3r board

[mortan]

Re: P35 Motherboards and DPC Latency Spiking

Hi! I just want to drop a note about how I solved the problem so others can try it too.

2 months or so ago I got a broken P35C-DS3R (Rev 1.x) from a friend because I fired up my DFI. I fixed the broken board, installed my hardware and had some time to be happy... till I installed Windows XP and tried to listen to some music with my Creative X-Fi audio card. Massive crackling and drop outs occured which drove me nuts. I did some research and found this and another thread about the DPC latency problem, grabbed DPC latency checker and saw that I suffered from the same problem.

Ok, enough background story, what did I do to finally fix it? At first I tried out BIOS versions F10 and F12, no enhancement. After that I downgraded to the old F4 BIOS, well it helped somewhat but I wasn't satisfied at all with the results. My next step was to contact the Gigabyte support team and ask for a beta BIOS because that's how (most of) the other people fixed it. They send me BIOS version F12f and suddenly the massive latency spikes seemed to disappear.

Well, not long after I installed Vista (64Bit) and the problem occured again, but only in Vista, XP was still running fine. So I again contacted the Gigabyte support and they told me that the problem is fixed with the F12(a?)* and above and I should uninstall all my installed drivers and update them to the newest version and retest. I did, still the same problem but I found out that if I run the tool CPU-Z *massive* drop outs accour. Well, they told me that's normal and I should remove the audio card and retest. I don't now if I did because it's some time ago, but I think so... But hold on, we are getting to the end!

Yesterday I installed Win7 64Bit (which by the way suffer from the same latency problems as Vista) and did some systematic tests. I noticed that the latency spikes occur while copying files from my SATA drives (I did not test IDE drives) but they seem to occur a bit arbitrary, sometimes more, other times less. I found a way to make the spikes really heavy: open IE 8 and surfing while copying files from my SATA drive. Now the funny thing: I also found a way making the spikes disappear! Running a program like Prime95 and stress my CPU while doing the same procedure.

I was a bit confused but found the problem quite soon: I had enabled CPU Enhanced Halt (C1E) and CPU EIST in my BIOS which lowers the clock of the CPU if it don't get stressed by applications. So my CPU was swapping from 2400MHz to 4000MHz (yep, overclocked E8600) while copying files which caused the latency problems. I disabled C1E and EIST and the problem disappeared!

I just want to mention that I also tried to: disable hardware, deinstall / upgrade drivers, unplug every SATA cable that I don't need, use the ICH9 SATA ports / Gigabyte SATA ports, reinstall the OS. But in the end nothing but upgrading my BIOS and disabling the mentioned features helped.

I've gone a bit into detail in the hope others can make use out of my explanations and do some of the tests too if my solution don't work for them.

Cheers and a happy day! Keep away from latency spikes :)

*maybe the "a" is a typo, because I never seen a F12a BIOS... maybe not


PS: My hardware:

Gigabyte P35C-DS3R (Rev. 1x)
Intel E8600 @4GHz
Nvidia 8800GT (G92)
6 GB Crucial RAM
Creative X-Fi Titanium Fatality PCIe
WinXP / Win7 / Linux

PPS: Some images from the problem

C1E and EIST on, low CPU load

http://img3.abload.de/img/c1e_eist_low_clockvg43.png

C1E and EIST on, heavy CPU load

http://img3.abload.de/img/c1e_eist_high_clockygfp.png

C1E and EIST off, low CPU load

http://img3.abload.de/img/no_c1e_no_eistzdt1.png

[Lsdmeasap]

Re: P35 Motherboards and DPC Latency Spiking

Thanks for posting your finds, hopefully this may help others sometime.

Overclocking is always the cure for everything

[clarsax]

Re: P35 Motherboards and DPC Latency Spiking

Hi to all, again.

Although I thought that moving to the latest BIOS release (F4) for my EP35C-DS3R (Rev. 2.1) board had fixed my audio problems, they did reappear after a few days. What has worked, for 3 weeks now, is reverting to Windows XP SP2, instead of SP3 to which I had upgraded earlier. The audio is now quite smooth.

The posting from 'mortan' did catch my attention. When I started looking through my BIOS selections, I did find, under MB Intelligent Tweaker (M.I.T.) the selections for C.I.A.2 (CPU INtellident Accelerator 2, currently set at Disabled, and Performance Enhance, currently set to Turbo [I believe that these were the default settings]. Are these the same as the CPU Enhanced Halt (C1E) and CPU EISTselections mentioned by mortan. If not, does anyone else know of the equivalent settings in F4 BIOS, if they are available.

Thanks very much.

[zorton]

Re: P35 Motherboards and DPC Latency Spiking

I already contacted to the moderator, i will try the bios mentioned earlier. I think i am late. I have F14 bios and no succes with windows 7 X64

That wasnt so bad in XP times. But i always had latency issue, always dig in to other things, like having 4 sound cards at the same time, 4 grafic cards, 4 motherboards, tons of cables... Never consider motherboard can cause this. Oh my dear God, i feel stupid.

I can't even play simple mp3 with fresh windows install.. The one that asks you update the library, the first action for media player? Already glitches, pops..

[Lsdmeasap]

Re: P35 Motherboards and DPC Latency Spiking

Hey Zorton,

These DPC latency issues have been resolved a long time ago, I know there is newer BIOSes now so maybe they are to blame but I doubt it. Could you try a few older ones and see if you find the same issue?

If you do see the issues still then it must be your hardware, drivers, or some program causing this. It is not the board, yes sometimes the BIOS can cause this, but not the board itself.

However, this boards BIOS issues with DPC have been resolved as of April 08.

Did you read this whole thread? If not, please see my post here (#228) for possible causes and or ways to narrow it down >>

http://forums.tweaktown.com/f69/p35-motherboards-dpc-latency-spiking-26456/index23.html#post264733

[colt45joe]

Re: P35 Motherboards and DPC Latency Spiking

i have a ga-ep35-ds4 (2.1) with latest bios (f6).

i figured out that it is the onboard network adapter causing these dpc latency issues. when the internet is in use, the red bars go up to 16,000 in that dpc latency program.

im just wondering, if i buy a pci network adapter and use that instead of the onboard, will that make things work just fine? or will i still have dpc latency issues?

[ozeh]

Re: P35 Motherboards and DPC Latency Spiking

hi colt45joe

I have the exact same board, revision and BIOS, however, I do not use the onboard RealTek LAN. Instead, I have a intel pro 1000 CT desktop adapter in my pci-e x1 slot. Running win 7 Pro x64, with no DPC latency spikes to be seen.

(I noticed, on Vista and Win 7 x64, if my power profile is set to balanced or power saver within windows, it seems to result in spikes on the graph, only when CPU usage is 0%. i.e. load up prime95 and suddenly it goes flatline green. If I turn the power options to "high performance", the results is a flatline green graph. "High performance" still clocks down the CPU when it's idle, so I don't know what the difference between those profiles really is.)

Out of interest, what OS and what power profile, if applicable, are you using?

[warren300]

Re: P35 Motherboards and DPC Latency Spiking

hi colt45joe

I have the exact same board, revision and BIOS, however, I do not use the onboard RealTek LAN. Instead, I have a intel pro 1000 CT desktop adapter in my pci-e x1 slot. Running win 7 Pro x64, with no DPC latency spikes to be seen.

(I noticed, on Vista and Win 7 x64, if my power profile is set to balanced or power saver within windows, it seems to result in spikes on the graph, only when CPU usage is 0%. i.e. load up prime95 and suddenly it goes flatline green. If I turn the power options to "high performance", the results is a flatline green graph. "High performance" still clocks down the CPU when it's idle, so I don't know what the difference between those profiles really is.)

Out of interest, what OS and what power profile, if applicable, are you using?

do you have c1e enhanced halt state in bios? under advanced cpu features? if so disable it and use balanced in win7,it will still throttle cpu but without the latency

[Lsdmeasap]

Re: P35 Motherboards and DPC Latency Spiking

A PCI Card could help, as could the latest RealTek drivers.

Please go ahead and update those before you decide to buy an adapter, in case it is not needed. And as said above test C1E and EIST Disabled as well

Here is the latest RealTek drivers for LAN
Realtek