today I've had some time to do some further testings with the latest driver release from Intel Homepage version 18.104.22.168
WLAN-Driver: 22.214.171.124 (07.10.2010)
LAN-Driver: 126.96.36.199 (26.03.2010)
Laptop: Lenovo T61 8889-2BG
Memory = 4 GB
Graphic Adapter: Nvidia Quadro NVS 140M with latest driver from Lenovo Website (186.94)
Tests done: Disable 4965AGN driver - DPC spikes disappear, re-enable and DPC spikes reappear every 10 seconds.
What I don't understand is, why the problem is not mentioned under the "Known Issues" here: http://downloadmirror.intel.com/19514/eng/relnotes.htm#issues2
On 16.11.2010 IIlenek from Intel Customer Support mentioned, that Intel developer are working to fix the problem for Intel® Wireless WiFi Link 4965AGN adapters as did it for 5000 and 6000 series adapters, the version above is dated to the 07.10.2010 so that the driver is older than the posting.
Another posting here says that Intel® Wireless WiFi Link 4965AGN is “legacy” hardware now. Is there still a chance to get driver with a fix or are we at a loss? If I understand the informations on Intel Homepage correctly Windows 7 64 Bit is still a supported operating system for this chip. Please tell us what we could provide for additional informations. I'm a software engineer, too and from my point of view it cannot be so difficult to fix within over 2 years.
Today (22.02.2011) I did some further testings:
- setting the power mixer of NV GPU in registry to off as mentioned in Lenovo Forum (http://forums.lenovo.com/t5/T61-and-prior-T-series-ThinkPad/Audio-stutter-on-T61p/td-p/43413/page/45) doesn't help. I tried as well different configurations of the registry key "PerfLevelSrc" (3322 and 2222).
- I analysed the GPU clock using GPU-Z. There is no difference if GPU is running with 169MHz or 400MHz clock speed
- When disabling the WLAN adapter the DPC's stop. The screenshot shows the last yellow spike and the big red spike is the point when the adapter is disabled in hardware control center:
Update (23.02.2011) installation of Windows 7 SP1:
- installing the service pack 1 for Windows 7 64bit does not fix the problem.
Well done now the latest driver (188.8.131.52) doesn't even work after suspend or resume resulting in limited connectivity or empty WLAN network list. Definnetly if I were one of those replacing this WLAN card I would go with another manufacturer like Broadcom or Atheros as they are focused on wireless products and may give at least a base support.
Yes it is frustrating that apparently the Intel engineers still haven't solved this for Windows 7, 64 bit. Perhaps there too few of us users to make it worth the time and effort to fix since this is now legacy hardware. However, there are still a number of these cards still in service (as evidenced by this thread), and so I'm sure Intel has tried to fix it but failed. I'm sure that with the 'Centrino' label, Intel wants to be a major player in WiFi technology; but it does make it diffulcult for some of us users if they can't maintain their drivers as well as other vendors.
Good suggestion to try Broadcom or Atheros products.I'll check with Lenovo support to make sure that one of their WiFi cards are "approved" in the most recent BIOS for my T61p machine. Otherwise (like the newer Intel cards), my machine may not boot up if it doesn't see the Broadcom or Atheros cards on an approved list of network adapters.
I actually have the Intel WiFi link 5100 AGN driver and it also causes horrendous audio glitches. It's come to a sorry state of affairs when a company the size of Intel can't write a driver. Windows Vista 32 bit reports that I have the most up to date driver (but it is 184.108.40.206), yet using DPC latency checker and Latency Mon 2.03 I can prove conclusively that it and the Microsoft ACPI CompliantControl Method Battery are wholly responsible for all audio glitches in my system. The WiFi driver is by far the worst offender. Do you have an update? Where do I find it?
I installed the latest Intel® PROSet/Wireless Software and Driver for Windows 7 64-Bit* (Version 220.127.116.11) from Intel Homepage.
Unfortunately only the Software and not the included driver was updated so that this version did _not_ fix the problem. Only disabling the wireless adapter using hardware manager helps to stop DPCs.
@Intel: Would it be possible to get a statement from official side?
Using Vista Ultimate 32bit. I was struggling with it for months.
Updating the drivers didn`t help.
It looks like the antivirus (ESET SMART SECURITY) was causing the problem.
After unchecking the checkbox Eset Personal Firewall in the properties of the wireless card
problem is gone.
Hope this will help.
Just read through this topic, i've been having the same problem for ages. Disable the wifi and the spikes stop, enable it and they're back. Luckily mine are in the green, although if i've left the system on for a while they sometimes go yellow. Still i find it unacceptable, as ndis.sys is still the slowest thing on my system with regard to dpc latency.
My wifi card is the 3945abg btw, different from the one in this thread. Same problem tho!
I've got an Acer/Windows 7 laptop and I have nasty audio glitches all of the times. I have monitored the glitches to realise that some of them are coming from the batteries. But the nastiest of them all are from the Intel(R) WiFi Link 5100 AGN. My 2010 laptop can't even play a cd straight or stream a youtube video with the antivirus on. And this issue is not a new at all. What a shame!
Since I use computers to compose music, I will carefully avoid Intel product for my next computer purchase.
I have resigned myself to the conclusion the Intel cannot (or will not commit sufficient resources) to fix this. Since I use my laptop for mission critical, live performance, I have a shortcut on my Start menu to the Hardware Manager so that I can toggle the wireless card on-and-off quickly to save time. Apparently wireless drivers from all manufacturers are prone DPC latency problems. Although I don't think I'll abandon PC's because of this, I will check this with every new laptop I purchase to make sure that the wireless card is OK for pro audio environments (at least until Microsoft releases their next version of Windows that is!).
I too had DPC spikes every 10 seconds (along with a lot of other spikes) with my Intel® Centrino® Ultimate-N 6300. After a load of troubleshooting, I installed the latest (14.3.1) driver (Intel® PROSet/Wireless Software and Drivers for Windows 7 64-Bit*) and now everything seems to be working much, much better.