[mknabster]

I'm running XP Pro SP2 on my MBP on a 70GB partition, which it will be made larger not too far down the road. I have been having problems with the sound quality ever since i have had it. Now it only happens in XP, not in OSX, which is why i'm not going to contact Apple about it, my product support is expired anyways. After so long of use, it does depend though, my sound starts to skip when i'm listening to music or playing a game, and it even goes to the extent of slowing down the entire computer so that its performance is skipping as well. The only way to fix it, is to restart. Like a few hours ago, i had it on, playing NFS Undercover, i wasn't playing for too long, about 45mins i'd say, and it started to happen. So i restarted, and within 15mins, happened again with a music game called Audiosurf. Has anyone ever hear of this before?

[Quicksilver]

Yep. Sounds like a very well-known problem with Apple's Windows drivers, and unfortunately, I don't think Apple is interested in improving them. If they were even mildly interested in making Windows on a Mac a better experience than Windows on a PC, they probably would've started with some decent power conservation routines, or a multi-touch trackpad driver.

My frustration aside, the root of the problem lies with the wireless network driver. Even if you're not connected to a network, it eventually goes crazy, causing some pretty nasty audio issues when your system load goes above a certain threshold.

The solution is to view all of your network connections and disable your wireless connection when you absolutely don't need it. However, there's a caveat: if you try to disable your wireless card AFTER you start hearing those audio artifacts, Windows will definitely lock up. Do it beforehand, and you'll be fine.

[mknabster]

Quicksilver, on December 15th 2008, 03:19 PM, said:

Yep. Sounds like a very well-known problem with Apple's Windows drivers, and unfortunately, Apple's not interested in improving them.

The core of the problem lies with the wireless network driver. Even if you're not connected to a network, it eventually goes crazy, causing some pretty nasty audio issues when your CPU load goes above a certain threshold. The solution is to view all of your network connections and disable your wireless connection when you absolutely don't need it. However, there's a caveat: if you try to disable your wireless card AFTER you start hearing those audio artifacts, your system is almost guaranteed to freeze. Do it beforehand, and you'll be fine.

Huh that's interesting, and i thought it was the audio card acting up. How could a wireless card do something like that?

[Quicksilver]

Since it's highly unlikely that the wireless driver can interfere with the audio driver directly, the robotic/choppy sound you've been hearing is probably the result of your Southbridge (scan this over if you have a second) becoming overloaded. I've noticed that the audio problems get worse as I start hitting the hard drive, and if you look at the big chart on the page I linked to, it should make sense--your hard drive, audio subsystem, and network traffic all travel through the Southbridge. Factor in a badly-misbehaving driver, and you have a potential traffic-jam.

Interestingly, if it wasn't for the fact that you were listening to audio, this problem might have gone unnoticed (or at least, it might not have bothered you). Unfortunately, audio data is one of the few things on the bus that can't be momentarily delayed without some major ramifications, and as far as I'm concerned, the problem should've been caught by Apple before the Boot Camp beta ever started.

As it stands, we're pretty much stuck with Apple's half-assed software. These days, I automatically replace Apple's video and audio drivers each time I update Windows, but the internal wireless card has evaded me. I'm not sure who makes it. In any event, I could write into Apple asking them to fix this issue, or write an article about Apple lambasting them for negligence, but I think that the quality of the current software set (just look at your machine's trackpad--it almost feels like a D-Pad) speaks volumes. It's almost as if someone at Apple stopped the Mac OS X team from finishing the job to spite Microsoft (or Windows users). Hence, complaining seems pretty futile.

[bobbob]

Quicksilver, on December 16th 2008, 10:30 AM, said:

Since it's highly unlikely that the wireless driver can interfere with the audio driver directly

It's probably doing something in an interrupt handler that has a high latency, deferring the audio driver and causing bad stuttering.

[Quicksilver]

bobbob, on December 16th 2008, 06:50 PM, said:

It's probably doing something in an interrupt handler that has a high latency, deferring the audio driver and causing bad stuttering.

You're probably right--the audio artifacts are basically a series of short audio pauses, and they sound pretty evenly spaced. Unfortunately, I don't know Windows well enough to know the priority level of audio-related interrupts, but if you're right, network interrupts take precedence over them. I wonder if a HD Tach scan (which usually plots a smooth curve) would turn into a sawtooth. Maybe I'll give it a try in a few days when I'm done with finals.

[mknabster]

You know what, i actually tried disabling my network devices, and that did the trick. How do yuo update the video drivers in your system? I have been trying to figure that out for awhile, but each one i install, it says it doesn't see any compatible devices.

[Quicksilver]

Don't disable all of your network devices--that's unnecessary. Just disable your wireless card when you're not using it.

---------

Are you running a newer MacBook Pro with a GeForce 8600M GT, or a older one with an ATI X1600 Mobility? If it's the former, take a trip over to http://laptopvideo2go.com/forum/, and try the Forceware release mentioned in my signature--I update it with the latest "known good" Forceware version frequently, since I check the site once or twice a week.

Installation is a breeze: if you're paranoid, you can use something like Driver Sweeper to wipe out your old Forceware installation before installing a newer version. Either way, just grab the installer archive and modded .inf file off the top of the forum entry. Run the installer archive, and tell it to dump the Forceware installer on your desktop. Then drop the modded .inf file into the resulting folder (select the "replace" option when it's presented), and run the Setup.exe. Restart, delete the crap strewn across your desktop, and you're all set.

Oh, and before I get any further--don't expect a significant performance boost. There's only so much mobility cards can do, and while the newer software might give you a few percentage points here and there and seriously increase your system's compatibility with the latest DX9/DX10 games, it can't violate the laws governing computing power.

By the way, the reason why you haven't been able to install the standard nVidia drivers off the web is because your mobile GPU isn't on the driver software's list of compatible hardware. There's a reason for that: laptops vary widely in their physical design and ability to deal with heat--the end result is that each mobile GPU is essentially a custom-configured unit. If you made it this far, note that the "modded" .inf that I referred to earlier was a user-created expanded list of video hardware. If you tried to run the Forceware setup.exe before you replaced the original .inf, you would've gotten the standard error about incompatible hardware.

[mknabster]

I have the newer MBP with the 8600M GT by Nvidia. I actually was able to find DX10 for XP, and i have noticed a slight performance increase with that installed. What something like Driver Detective be able to pick up the drivers i might need?

[Quicksilver]

I've never heard of Driver Detective, but I'm fairly certain that it won't work. Just go through the route I explained earlier, and you'll do just fine.

[mknabster]

Quicksilver, on December 17th 2008, 09:06 PM, said:

I've never heard of Driver Detective, but I'm fairly certain that it won't work. Just go through the route I explained earlier, and you'll do just fine.

Thanks a bunch for all your help Quicksilver, i really appreciate it!