Playing music severely degrades network transfer performance in Vista

Summary:Playing music while transferring files across a network severely impacts performance.

[UPDATE - Read part 2 of this post here] 

In the interests of complaining rather than whining about Vista I though it would be interesting to document this bug/feature in Windows Vista that I heard about earlier today.

Basically, here's how the bug is being described on a computing forum by a forum member going by the name of dloneranger:

background - M2N32-SLI DELUXE, 5600+ cpu, 2Gb ram, dual boot system xp and vista

on xp the network speed was between 30-50% on vista it was stuck at just over 5%

so I followed all the advice about disabling autotuning etc, tried setting all the differerent lan driver settings, played with the tcp window size, latest drivers etc .... none of it made a bit of difference, I was still stuck on 5% usage <grrrr>

until.... I stopped playing music... doesn't matter what I play back music with, if it's playing or paused the lan speed seems to be locked at the 5% stopping playback or quitting the player lets the file copy go to the 30-50% instantly

oddly, if I play a video, the lan transfers go up to 10%

playing an mp3 and video at the same time gives the same 10% and the usage stays the same even if the video is closed

after that the lan is limited to 10% when any audio/video programs are playing (as soon as they're closed it jumps back up to 30-50%, start them and it's down to the 10% again)

I can see it's not cpu usage, as it happens even while the video/audio is paused

In summary - not a clue why it happens , but I've seen this behaviour on a few different machines now

As you could imagine, I was skeptical that playing music would have an effect on network transfer speeds - so I decided if I could see the phenomenon for myself.  Interestingly enough, I could.  Quite easily.

Here's the deal.  The system I tried this on is a Pentium 950D rig with a Marvell Yukon 88E8062 PCI-E IPMI Gigabit Ethernet controller. 

Here's a test transfer of a 650MB Linspire ISO from another PC on my network onto mine (both PCs have gigabit Ethernet adaptors):

No music playing during transfer

As you can see I'm getting about 25% on average.  OK, now with Windows Media Player 11 running and playing a Vista-supplied sample audio file (Symphony No. 3 in E-flat major, Op. 55, 'Eroica' - Scherzo- Allegro vivace) here's what I saw:

Music playing during network transfer

This time I'm getting half the performance that I was before without the music playing.  As a consequence the file took twice as long to transfer.  Just to make a point, here's a single screenshot showing transfers of the same file with both music playing and later without:

Transfer with both music playing and without
 

Here's what happens when you start playing a music file WMP 11 while a network - as you can see the transfer speed drops almost instantly:

Music started mid transfer

Something really odd happens when you stop WMP 11 during a file transfer.  The transfer stops dead for a few seconds before resuming at full speed:

Stopping WMP 11 during a file transfer

Here's another screen grab showing how readily repeatable this phenomenon is:

Easily repeatable Â…
 

I guess the moral of the story is, don't play music while transferring files across a network.

Let's see if complaining rather than whining has any effect on how fast these bugs are fixed ...

UPDATE

A few people have asked if I have the latest performance and stability updates from Microsoft (specifically KB938194-x64, KB938194-x86, KB938979-x64  and KB938979-x86) installed.  Yes, this system has them installed:

Performance and stability updates applied

Topics: Networking, Microsoft, Windows

About

Adrian Kingsley-Hughes is an internationally published technology author who has devoted over a decade to helping users get the most from technology -- whether that be by learning to program, building a PC from a pile of parts, or helping them get the most from their new MP3 player or digital camera.Adrian has authored/co-authored technic... Full Bio

zdnet_core.socialButton.googleLabel Contact Disclosure

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.

Related Stories

The best of ZDNet, delivered

You have been successfully signed up. To sign up for more newsletters or to manage your account, visit the Newsletter Subscription Center.
Subscription failed.