Windows 7 / Sandy Bridge DPC

[Bob Moose]

I just ran that program on Win 7 64 bit. It maxed out at 144 so I can't see it being an O/S fault.

Great! I did not want to go back to XP.

Out of interest, did you get a good Sandybridge or one with the duff USB controller?

I was not aware of this. Are some Sandybridge CPUs or motherboards problematic?

-j

[Drinking]

Every motherboard that hit the shops was faulty. One of the biggest Intell cockups to date. Some shops refused to sell the stock and some sold them on the promise that once the new batch was released a replacement was to be available. I read the other week that the new ones are now in circulation so you might have a good one.

Its worth checking. Do a search online, you should find pleanty of stuff on it.

[Bob Moose]

I have the Gigabyte GA-P67A-UD3-B3 motherboard, at least as written on the box and on the board itself (it's a sticker that overrides the original name actually, but I did not remove it for seeing what is printed below).
As far as I understand only B2 was problematic (B3 is ok).

Best,
-j

[Pete Kaine]

OP has a B3 board so it's fine. It was the sata controller and not the usb controller that had a problem. All the B3's are fixed and working fine so not the problem.

DPC under 750us should be fine and not causing issue. Saying that I'd expect that board to be hitting around a 100 on average if not far lower.

Uninstall Easytune like I mentioned in the other thread. That normally does some pretty nasty things to DPC and may well resolve it here.

[InactiveX]

Graphics: ASUS EN210 1GB DDR3 fanless

I've got one of these, but the 512MB version, and it adds quite a lot to DPC latency.

Have you got another GPU you could try to narrow it down?

[Bob Moose]

No I don't have any other GPU. Initially I had chosen a different graphic card but it was not available at all here so I went for the ASUS.

I will first check how DPC latency is without Easytune, and will try another graphic cards in case latency is still high

Best,
-j

[Pete Kaine]

Some revisions of the Nvidia driver can be problematic. Make sure you download the latest one as that appears to be fairly alright. Got a G210 plugged into the board next to me and I'm seeing 60 - 100 with no spikes.

[mick.n]

Bob, i just finished building a sandybridge system the other day using the same components as yours (Except the ram which is 4gb corsair & graphics is ATI radeon 5400 series) .

Uninstalling easytune will reduce your dpc figures by quite a lot....it certainly did on my new system.

My DPC shows 53us with a max of 121us after logging on to windows 7 (64 bit). Before, with easytune installed, it was WAY higher than it is now.

Allthough running a track in cubase 5 gives a slightly higher reading, IIRC it was 89us with a max of 158.

[Bob Moose]

EDIT2: ASUS EN210 SILENT/DI/1GD3/V2(LP) driver

I installed version 259.44 (2011/03/23) instead of 267.85 (2011/05/04).

In this case, the 16000+ us DPC spikes no longer occur, actually the DPC latency oscillates between near-zero and 900 us (most of the time below 500). When C1E, EIST and HPET are disabled in the BIOS the DPC latency similar, though more constant between 200 and 500 us.

So it's more useable, but still crappy.

Does it mean that I should get another graphic card?

Best,
-j

[Bob Moose]

problem fixed

I replaced the Asus EN210 graphics by a Sapphire HD5450 512MB DDR3 HDMI/DVI/VGA card and it works great. I only installed the graphics driver, nothing else.
For now I left C1E, EIST and HPET disabled in the BIOS as it works correctly.

During 1H30 of use, the maximum DPC latency was 276 us, but actually it runs between 5 and 20 us most of the time. Latency spikes occur very rarely, and usually they are below 100 us.

I knew the EN210 graphics card was problematic because when uninstalling its driver the DPC latency was ok. Moreover, different EN210 drivers resulted in different non-satisfying latency behaviours.

Thanks a lot everybody for helping me find the problems (EasyTune + EN210). Now I can use this computer for serious low latency audio.

Cheers,
-j

[mick.n]

Happy to hear you solved the issue bob. Incidentally, the sapphire graphics card you are using is the same that i used in my new build.

My latency is now 23us/ 34us max.....not as good as your readings!Still at the "tweaking stage" at the moment though.

[Skyline]

Uninstall Easytune like I mentioned in the other thread. That normally does some pretty nasty things to DPC and may well resolve it here.

Agreed - I tried to publicise this nastiness back in my July 2010 PC Notes column:

www.soundonsound.com/sos/jul10/articles ... 0710.htm#3

A lot of musicians have fallen foul of this utility

Martin

How do I check if I've got EasyTune and how do I remove it if I have?

John

[BarnyBarn]

hi guys

haven't posted here in a while. but this topic caught my attention.

I take it that the first card the op used was an nVidia card? nVidia are having some serious problems regarding DPC spikes with their drivers.

the spikes on desktop machines seem to happen when you start doing something a bit more GPU intensive like watching a HD video on you tube. that's how I test it anyway. that's when the high spikes occur.

on laptops it's a whole other world of pain. but using this tool (http://somemorebytes.com/wp/index.php/s ... pmmanager/) you can get it somewhat under control. naturally, YMMV.

the problem is the powermizer feature nVidia uses. there's a very long thread on nVidia's forum full of people having DPC issues on their laptops.

I have no idea why nVidia a) apparently are unable to fix this problem and b) why they apparently don't care about it. I find it rather baffling.

a good way to double check that it really is the graphics driver that's causing trouble is using this tool: http://resplendence.com/latencymon

some of you probably already know it. very helpful.