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mojojoj0
Posts: 17
Registered: ‎09-06-2010
Location: Austin, TX
Accepted Solution

DPC latency + audio/mouse skip and stutter on t420s

[ Edited ]

Hello fellow thinkpad owners,

 

I have a new t420s (41717FU) core i7, 8GB RAM, and NVS 4200M discrete, win 7 64-bit pro.  I use the minidock with 2 external 28" displays on DVI out.  

 

I discovered major issues with latency with this machine; very noticeable loss of control for about half a second, plus annoying audio stutter, especially concurrent with network activity. This is quite frustrating, especially for a machine that is supposed to be high end core i7 with discrete graphics. I had a t410s previously and also had latency problems, and I know this is a real problem with several different models (just search 'annoying audio') on the forums.

 

I have used dpc latency checker as well as latency mon and narrowed the probable culprit to the network drivers associated with the gigabit ethernet.  It took me a while to discover the relationship to the Intel 82579LM, since LatencyMon will identify the problem with NDIS.sys or NETIO.sys, giving sporadic latencies over 20000 microsecs, which made me think it was a Win 7 tcp stack issue or maybe some internal windows firewall blocking.  During these spikes, the audio stutters, the mouse won't move, everything on the system just stalls for a split second.  Temps on CPU seem within normal limits at about 70-80C.  I've read everything I could find about this issue, including problems with NVIDIA drivers, ACPI, firewall/antivirus, etc etc, and tried most of those suggestions.  

 

I spent a long time doing all kinds of testing, putting the machine on AC power and max performance, shut down various devices, disabled any component power-off states, disabled NVIDIA and displays, changed bios settings etc.  

 

After all of this, I *know* my issue is related to the Intel Ethernet component, because if I disable it and use wireless connectivity (or no network at all) the problem simply goes away.  Surprisingly, the wireless Centrino adapter, though slower, functions without any problem affecting DPC latency and I have no stutter with that (many have previously identified the wireless adapter being a problem especially related to power mgt).

 

Unfortunately, I require an ethernet connection.  So just disabling that adapter is not an option.  Here is what I've done to workaround the issue, though I wish it would be fixed for good with some kind of update from Lenovo, though I've called and emailed them and they seem to be ignoring this issue.  

 

**** UPDATE 3/1/2012 ****  

 

SOLUTION RIGHT HERE:  INSTALL AN OLDER NETWORK DRIVER FROM HP (sounds crazy, but it works).  See below link to driver download.

I (and many other owners of T420, 520, etc - see other posts if you doubt it) have *no* latency after installing this older driver from HP. But as soon as I install the Lenovo-provided driver 11.12.38.* or any later one from Microsoft or the Intel generic driver (intel no longer publishes the old driver), I see *immediate* problems with latency, mouse and audio stutter. But use the driver published by HP (specifically version 11.12.36.0, published 5/4/2011) -- Problem solved!  I tested with streaming and browsing for several hours and no spiking or stutter.

 

Here's where to get the english language download from HP:  >> DRIVER DOWNLOAD PAGE HERE <<

 

Lenovo, PLEASE: this is strong evidence of a faulty driver for those of us with a t420s (and other thinkpad users out there using the intel 82579LM chip under x64).  I encourage you to review this solution and engineer an update for the Intel gigabit adapter, or at minimum, roll back to the older driver or some Lenovo approved derivative so it doesn't cause all of us notebook users such a major headache.  It's very bizarre that we would need to go to another manufacturer to get a working driver...I was ready to return the machine over this issue! 

 

Aside from that adapter problem, I've been pleased with the t420s performance and features.  Thanks again lopiuh for this workaround.  

 

Mojojojo in Austin TX

 

ADMIN EDIT - Lenovo is testing a beta ethernet driver.   If you are willing to try it, please see the link below, and my post on page 6 of this thread. - mark

https://www.dropbox.com/s/llcgjaf45xpuoam/83rw20w1.zip

 

***** END UPDATE *****

 

**** OLDER STUFF I TRIED, which somewhat helped, but the real solution is to use the old HP DRIVER above. ****** 

 

Basically, my approach was to reduce the 'auto' parameters for the adapter, to reduce the amount of logic running on the adapter itself.

 

1. Install the PRO set extension tools on this adapter, so you can more easily manage advanced settings.  I think Lenovo offers a version in the driver downloads area which adds this management extension, but it is not the standard one offered by the system update utility, and the intel site has a later driver, so I gambled and downloaded the latest version from Intel for this adapter.  It installed without issue, but I'm sure Lenovo would prefer you stick with their OEM packages. Anyway, here's the one I used: http://www.intel.com/support/ethernetcomponents/controllers/82579/sb/CS-032239.htm (link near the top for the download).  You may want to make a system restore point before you install any drivers outside of OEM approved.

 

2.  Change the default settings for the adapter in Device Manager.  Right click properties for the Intel 82579LM in Network Adapters.  Change the link speed (if the extension was installed properly, you'll see the intel logo on the tab for Link Speed, and a choice for Speed and Duplex.  Change this from 'Auto Negotiate' to whatever speed your network is.  I have gigabit full duplex, and that worked for me.  This by itself was the biggest improvement with DPC latency.

 

3. Go to the Advanced tab.  I took the approach that I wanted to disable as much 'auto' stuff as possible, and force the adapter to use a particular setting.  Thus: 

Interrupt Moderation: Disabled

Jumbo Packet: 9014 bytes (I have several devices that can use bigger packets on network, such as readynas)

Performance Options: click properties: Flow control - Disabled; Interrupt Moderation Rate - Off; and then double the receive and transmit buffer sizes (for me this was 512 and 1024 respectively).

 

I hope this may be helpful to some other owners, but I don't work for Lenovo or Intel so please don't blame me if something goes wrong during your tweaking.  This worked (for me) to significantly reduce stuttering problems, though they are not completely gone; your mileage may vary.  If you have this same problem, I'd appreciate if you would post about it so I can understand if it is a more widespread problem.

 

Good luck, mojojojo

Austin, TX

 

 

 

 

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ColonelONeill
Posts: 6,784
Registered: ‎12-26-2009
Location: Toronto
0

Re: DPC latency + audio/mouse skip and stutter on t420s

What if you use the drivers off of the Intel site? It offers more settings and may have fixed the underlying issue.

There's also a function i Windows that allows you to offload calculations to the NIC or prevent it from doing that. It defaults to the latter, so you may want to enable it:
http://technet.microsoft.com/en-us/library/gg162682%28WS.10%29.aspx

Not sure if the card supports it though.
W520: i7-2720QM, Q2000M at 1090/695/1390, 22GB RAM, 500GB HDD, FHD screen
TPT1: 1839-23U, stock ICS
X61T: L7500, 3GB RAM, 500GB HDD, XGA screen, Ultrabase
Guru
PeterTWJ
Posts: 1,102
Registered: ‎05-29-2010
Location: Singapore
0

Re: DPC latency + audio/mouse skip and stutter on t420s

[ Edited ]

Hi mojojoj0

For my W520, up till now I do not have latency issues. My set of configuration for Intel NIC is slight different.

 

2. This may cause connection problems when you are connecting to different network. Different network (switches, routers) have different configuration. Previously I set it to Gigabit Full Duplex, I can't connect to any 10/100 network until I change it back to Auto negotiation.

 

I would suggest changing back to auto negotiation when you are connecting to outside network, not all places are using gigabit switches.

 

3. Interesting, I guess I would try it and feedback and see how much improvement for network performance.
From what I know, increasing receive and transmit buffer improve NIC and network card performance, but computer may slightly more memory.

 

Maybe you can try this, part of my settings:
Large Send Offload (IPv4) & (IPv6) Enabled

TCP & UDP Checksum Offload (IPv4) & (IPv6) Tx & Rx Enabled
IPv4 Checksum Offload Tx & Rx Enabled 

 

Hope this helps! :smileyvery-happy:

 

Cheers :smileyvery-happy:

Peter
(Current: W520 4284-A99) (Refunded: W510 4876-A11)

=============================================
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Mark it as solved if the solution works for you, so it could be reference for others in the future :smileyvery-happy:

 

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http://forums.lenovo.com/t5/W-Series-ThinkPad-Lapt​ops/W520-Sound-Enhancement-Thread/m-p/451401#M155... 

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PeterTWJ
Posts: 1,102
Registered: ‎05-29-2010
Location: Singapore
0

Re: DPC latency + audio/mouse skip and stutter on t420s

Hi ColonelONeill

I guess it supports offload calculations. Settings inside have few options for Offload.

For that function, I enabled it and optimize my network performance by using TCP Optimizer. I am not sure about it, maybe because of this tool, I have not seen any stutter on my refunded W510, current W520 or other machines. 
http://www.speedguide.net/downloads.php 

 

Hope it helps! :smileyvery-happy:

Cheers :smileyvery-happy:

Peter
(Current: W520 4284-A99) (Refunded: W510 4876-A11)

=============================================
Does someone’s post help you? Give them kudos as a reward, as they will do better to improve :smileyvery-happy:

Mark it as solved if the solution works for you, so it could be reference for others in the future :smileyvery-happy:

 

Dolby Home Theater v4 (ThinkMix V2)!

http://forums.lenovo.com/t5/W-Series-ThinkPad-Lapt​ops/W520-Sound-Enhancement-Thread/m-p/451401#M155... 

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mojojoj0
Posts: 17
Registered: ‎09-06-2010
Location: Austin, TX
0

Re: DPC latency + audio/mouse skip and stutter on t420s

I am using the intel generic drivers that include the Proset extension. But same issue occurred with the Lenovo-issued drivers.  

 

Unfortunately, nothing really fixes my problem, these tweaks only reduce the frequency of a stutter from every 1-2 mins to every 5-6 mins. Inevitably, the computer stutters when using the gigabit adapter, and DPC Latency Checker throws a big red spike that is off the scale.  Right in the middle of a long run of sub-300 microsec green bars.  Using wireless adapter, never a problem; same thing when using no network connection, never a hiccup, everything runs as smooth as silk.  

 

Maybe I have a flaky adapter, and should return the unit for a replacement.  I've spent way too much time trying to fix it myself, that's for sure.  It is the only issue I've had with the machine.

Ctrl-Alt-Del
niklaas
Posts: 12
Registered: ‎11-29-2011
Location: Vienna
0

Re: DPC latency + audio/mouse skip and stutter on t420s

[ Edited ]

Hello mojojoj0,

 

I've got a very similiar issue on my T420, just wanted to let you know. You can also have a look at my thread ( http://forums.lenovo.com/t5/T400-T500-and-newer-T-series/T420-sound-buzzes-sometimes-when-playing-vi... ) that I posted today.

 

The difference is that I still get too high latency although I deactivate LAN and WLAN device.

 

I would really appreciate any help (especially a solution by Lenovo!) because this is an issue that may not exist on such machines.

 

Niklaas 

Guru
PeterTWJ
Posts: 1,102
Registered: ‎05-29-2010
Location: Singapore
0

Re: DPC latency + audio/mouse skip and stutter on t420s

Hi all

If I don't mess anything with the NIC settings, disconnect or reconnect, the average latency would range around 80 - 200. If I messed around the settings, disable / enable adapter, disconnect / reconnect, there would be a sudden spike up to 10000+.

My driver version shown in Device Manager is 11.12.38.0, should be Lenovo version.

Cheers :smileyvery-happy:

Peter
(Current: W520 4284-A99) (Refunded: W510 4876-A11)

=============================================
Does someone’s post help you? Give them kudos as a reward, as they will do better to improve :smileyvery-happy:

Mark it as solved if the solution works for you, so it could be reference for others in the future :smileyvery-happy:

 

Dolby Home Theater v4 (ThinkMix V2)!

http://forums.lenovo.com/t5/W-Series-ThinkPad-Lapt​ops/W520-Sound-Enhancement-Thread/m-p/451401#M155... 

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lopiuh
Posts: 3
Registered: ‎12-04-2011
Location: Germany
0

Re: DPC latency + audio/mouse skip and stutter on t420s

Hi,

 

using older Version of ethernet driver solved problem for me. Versions which worked (64Bit Win7):

Version from _xx_12_2010

(which were on my stock image of the T420)

 

64Bit: SP53631_11.12.36.0_04.05.2011

lend from HP_page: 

http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?lang=de&cc=de&prodTypeId=32...

Guru
PeterTWJ
Posts: 1,102
Registered: ‎05-29-2010
Location: Singapore
0

Re: DPC latency + audio/mouse skip and stutter on t420s

Hi niklaas,

The Network Card is from Intel, I guess manufacturers like Lenovo would also wants a solution from Intel. It is affected on other machines, even on some servers.

 

Hi all,

This is the workaround and it resolves the high dpc latency issues. From what I know, High DPC is caused by IPv4 + IPv6 Offloading, which the Intel NIC card or the driver itself cold not handle.

http://forums.lenovo.com/t5/W-Series-ThinkPad-Laptops/Workaround-for-high-DPC-issues-for-X-T-and-W-0...

Hope this helps! :smileyvery-happy:

Cheers :smileyvery-happy:

Peter
(Current: W520 4284-A99) (Refunded: W510 4876-A11)

=============================================

Does someone’s post help you? Give them kudos as a reward, as they will do better to improve :smileyvery-happy:

Mark it as solved if the solution works for you, so it could be reference for others in the future :smileyvery-happy:

 

Dolby Home Theater v4 (ThinkMix V2)!

http://forums.lenovo.com/t5/W-Series-ThinkPad-Lapt​ops/W520-Sound-Enhancement-Thread/m-p/451401#M155...  

Paper Tape
Baron86
Posts: 3
Registered: ‎11-20-2011
Location: Germany
0

Re: DPC latency + audio/mouse skip and stutter on t420s

yes. I can confirm this solution works for my w520. just download the older gigabit driver from hp website