Re: Horrendous DPC latency?

JaneL · ‎11-20-2007

sch8mid wrote:
I don't understand why none of the Lenovo guys in this forum tries to help out here either.

There are a few Lenovo employees roaming around in here helping out on a volunteer basis, but this is not an official support channel. Instead, this is designed to be a user-to-user support and discussion forum. You may or may not get an answer directly from one of the Lenovo employees as there are way more of us than them and all of them, even Mark, have full-time jobs doing other things.

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Jane

ThinkPad Slate, T410s, X301, X200 Tablet, T60p, HP TouchPad, iPad 4, iPhone 4S, IdeaTab A2107A
I am not a Lenovo Employee.
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gw3up69bxaq0 · ‎11-23-2008

my sl500 with vista64 running latency around 60us, but in 3-5minutes it draws a 53500us bar on the DPC checker.

my opinion is that the problem source is the ahci controller.

is lenovo support working on the problem?

XPenetrator · ‎11-17-2008

@Nonny: Yes I think we understood that. Thanks for putting your precious leisure time into this. I just thought it could've been easy to PM spacecadet an email address or a phone number of someone who knows what we're talking about here and saving him from going through what I know as "Dell Hell".

@gw3up69bxaq0: What makes you think that the AHCI controller does that? Any indices or observations you could share?

Zurdo82 · ‎12-13-2008

I'm also getting horrendous DPC latency. My SL400 finally arrived yesterday (after already having a very frustarting shopping/customer support experience) and I noticed the hiccups in the sounds as soon as I started to load my music to my new laptop.

I'm pretty much getting a flat red line around 10,000 us. http://i545.photobucket.com/albums/hh390/zurdo82/dpclatency.jpg

I actually wanted to give vista a try but I'll try to install XP. It's very annoying that I finally buy this thing to replace a much much older PC and I run into these annoying hiccups.

If this continues with XP, I'm not sure what I'll be able to do. Can the laptop be returned for something like this?

Zurdo82 · ‎12-13-2008

Ok, so I installed XP Pro without knowing what I was getting into - i.e:. streamlining XP, setting the BIOS to compatibility.

The experience is much better now but not exactly great - or even acceptable. http://i545.photobucket.com/albums/hh390/zurdo82/dpclatency_XP.jpg

I still need to update the AHCI driver. I'm not exactly happy with losing the Roxio Creator and other preinstalled software that could have come in handy.

******* UPDATE *************

I decided to install XP pro again and install every driver one by one. The results were much better than I could have anticipate. I simply used the lenovo system update and windows update to install everything without really paying attention.

This is the final DCP latency that I recorded:

http://i545.photobucket.com/albums/hh390/zurdo82/latency_final.jpg

I was missing a couple drivers so I downloaded lenovo system toolbox and lenovo system update.

I started to get some spikes after I downloaded the last 2 drivers/3 apps:

ThinkVantage Rescue and Recovery
RealTek LAN Driver
ATK Hotkey Driver
ThinkPad Power Management Driver
Active Protection System

I don't think I will keep messing with this thing anymore.

Now it's time for me to actually start using the laptop .

Good luck with any other findings.

Message Edited by Zurdo82 on 12-28-2008 09:33 PM

mmuddasar · ‎01-01-2009

I posted the following here:

http://forums.lenovo.com/lnv/board/message?board.id=SL_ThinkPads&thread.id=1346

FIXED IT!

The solution to my poor quality sound was to roll back an IDE ATA/ATAPI Controller driver in Device Manager. The controller to roll back the driver for is the Intel ICH9M-E/M SATA AHCI controller (which is enabled by Intel Matrix Storage Manager).

The latest version (8.1.0.1007) of the driver for this controller is automatically downloaded when using System Update. However rolling back to version 8.1.0.1001 solved the sound problem for me.

Please note that driver updates are designed to resolve issues, so by rolling back the driver you risk making your system vulnerable to issues it was previously protected from. See http://downloadmirror.intel.com/17059/eng/releasenotes.htm for details.

Hopefully Lenovo will get Intel to release a version of Matrix Storage Manager that doesn't clash with the sound.

XPenetrator · ‎11-17-2008

Glad you got that sorted for your playback problem. But the DPC screenshots after this fix are not quite what is probably desirable for professional low-latency realtime-audio this thread was about. That should (ideally) look like this:

Link to Picture

Moderator Note; Embedded picture larger than 50KB converted to link.

Message Edited by andyP on 01-02-2009 10:15 PM

front-of-house · ‎11-29-2008

XPenetrator wrote:
Glad you got that sorted for your playback problem. But the DPC screenshots after this fix are not quite what is probably desirable for professional low-latency realtime-audio this thread was about. That should (ideally) look like this:

Link to Picture

Moderator Note; Link to picture larger than 50KB converted to link.
Message Edited by andyP on 01-02-2009 09:39 PM

Well, if you have any ideas on how to get me in that range .... I'm all ears.

For the time being though, this "new fix" is substantially better than it was.

SL500 2746 CTO, 2.0 7370, 3 GB ram, Vista Hm. Prem.SP2
Bios ver. 1.24

dotlok · ‎12-28-2008

I just got a new SL400 laptop and was having sound problems - stuttering, breaks. After going through this post (and replies) I checked my dpc latency.... it was basically at 10,000us. After trying everything I could think of, I called the Lenovo help desk. After 3 calls with no solution, the guy told me that if they were even going to look further into it, I would have to reinstall the factory setting OS. Since I only got the computer recently I decided to do it. The sound problem did not go away. I checked the dpc latency again, with original factory settings, and no internet connection. It was still at 10,000, meaning that out of the box it was at that high level. I have no idea what to do. I'm really reluctant to call the lenovo help line again. I'm actually starting to regret paying more to buy what I thought was a quality product. I mean I could have paid $300-$400 less for a laptop and chances are it wouldn't have this issue, and if it did, for that price I wouldn't have minded spending more time trying to fix it, but I paid good money so I wouldn't have to deal with things like this.... not a happy customer.

bsteger · ‎12-15-2008

Wow yeah rolling back that driver worked great. dcplat is now almost always between 500 and 1000, where before it was almost always around 8000. Not perfect, I'm sure, but I can't hear pops and cracks and things anymore, so it's good enough for me. Thanks a lot, mmuddasar!