Dell Latitude DPC Latency Issues

Thank you. It's very kind.

 

I do not see a need to install the Intel Matrix Storage Driver at all IMO. The Intel INF provides a generic driver for the SATA AHCI mode when you install it.

With the Matrix Storage driver installed, my audio stutters, pops, and whatever, whenever my optical drive is slotted in. DPC Latency Timer reports values of ~10,000 constant. Removing the optical drive immediately stops all the audio issues.

Without the Matrix driver (using the Intel INF one), I have zero issues with audio or stability irregardless of whether my optical drive is in or not, or whether it is in use. My latency is around 1,000 with the INF driver. However, I cannot play audio CDs using Winamp, it seems to lock up the I/O of the system. (This issue goes away if I install the Matrix Storage driver, but I'm not interested to listen to stutters and pops in my music, be if from audio CD direct, or MP3!) Listening to audio discs using WMP, ripping audio discs using other software, and burning discs have no problems though.

 

I also recall that installing the Matrix Storage software fixed many of the burning problems that people (including myself) had when the E series was first launched.

John

 

Although I got to this point for completely unrelated reasons, I seem to have ended up with a constantly low latency (ie. almost entirely below 500 microseconds according to DPC).

I was having problems with my M4400 losing the connection to my access point (I've got the 5300 WiFi card) and was also having problems with my hard disk just stopping (Windows didn't freeze until it required the HD - for example the audio of streaming video would keep going whilst the picture froze).

I uninstalled all the Intel wireless drivers and utilities and then reinstalled just the drivers from the Intel website (12.2.0.0 is the latest release). I also installed the firmware update for the hard disk from Dell's website.

The wireless now seems to be working properly, the hard disk hasn't stopped working again (yet!) and I have a latency that's almost permanently in the green and usually below 200 microseconds.

I'd be interested to hear if anyone else has similar results!

 

Can someone post a link for this Intel inf please? I dont know what to look for on the intel site.

thanx

 

http://downloadcenter.intel.com/con...62&DwnldId=17227&strOSs=&OSFullName=&lang=eng

 

@ The Doctor

I don't see any .inf containing AHCI drivers in this package are you sure you're talking about the same thing as TWY?
If so....do i have to uninstall my current wireless drivers, install these for wifi and that'll provide me with an AHCI driver somehow? In that case i would also have to uninstall the ICH9M AHCI from the device manager, right?

@TWY

if the above is not correct could you give me a download link for the intel .inf you're talking about?

 

Sorry, those are just the Intel wifi drivers, not the AHCI.

I've got the Intel Matrix manager version 8.2.2.1001 installed, installing the latest version from Dell gave me the constantly high latencies when the dvd drive was plugged in so I downgraded back again.

Based on my experience, to get low latency I'd...

1) Install 8.2.2.1001 of the Intel Matrix software
2) Uninstall the Intel wireless application & drivers(if you have an Intel wireless card)
3) Install the latest Intel wifi drivers (from the link I posted above)
3) Install the firmware update for the Seagate hard disk from the Dell website

I've now got very low latency and haven't got any crackling or popping...

 

That's what i thought,
I've done all that except for the wifi stuff so i'll try that to see if i can get latency further down (not having any real issues now)

 

Just F.Y.I., as I previously mentioned, I and others still have latency issues with the 8.2 driver, just spikes every 10 seconds or so, unlike the constant 10ms+ latencies we experience with the 8.7 driver.

I previously suggested:

However, after working on another Vista reinstall, I now realize that the "Intel - Driver" for "Mobile Chipset" (R182522, 8/12/2008, 8.7.0.1007, A00) contains and installs the Intel 6.9.1.1001 driver ("Intel(R) ICH9M/M-E Family 4 Port SATA AHCI Controller - 2929", 2/20/2008). Using this driver, I have the same <500µs latencies that I have with the Microsoft driver, but presumably with more features and better support.

These versions are further interesting, given the dates. This shows 6.9 being released in 2008, while all the version 7 drivers available in the archive at Intel have 2007 dates. This seems a little backward, but so far, this "6.9" version is currently giving me the best results.