The irqs look ok. Try moving the 1394 card to a different PCI slot. If at all possible, get the 1394 and the video display on a separate bus. This issue can be solved without new equipment or changes to Vegas.

I have the SAME problem with my new computer, running WinXP Pro. Set up is as follows. SF, please comment. There must be something else to advise. Thanks.

Intel PIV 3.06 GHz
Soundblaster Audigy 2
512 MB PC1066 RDRAM
200 GB Ultra ATA 100 HD
Radeon 9700 Pro
WinXP Pro
Vegas + DVD
Samsung SyncMaster 191T

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SonicEPM >>> Try moving the 1394 card to a different PCI slot.
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I dont have an IEEE-1394 card.
The IEEE-1394 port is integrated to my mother board (MSI845PE Max2).

FWIW, I do not like using the built in audio and firewire chips. First, the audio is usually crap - half duplex and with limited sample rate. This could be a big problem when trying to record and listen to trakces at the same time. I'd get a pro style audio card like m-audio. Second, onboard stuff always shares IRQ's with the PCI slots. Get a nice PCI firewire card and put it in a slot that does not share an IRQ with anything. Go into your BIOS settings and disable onboard firewire and audio and use msinfo32 to check that IRQ's are not being shared on the PCI slot you stick the card into. Regardless of what you might think, it is impossible to determine which IRQ's get assigned to which PCI slots, even if you set them manually in the BIOS. W2k and WinXP will always assign them as it sees fit. Just experiment and you'll understand how the IRQ's are assigned on your system.

If you also have a highpoint controller, it will share an IRQ with a PCI slot (usually PCI2) which is the third slot (0 numbering). PCI0 always shares IRQ with AGP so don't use that. PCI1 (slot 2) usually never shares with anything. Good spot for the firewire card.

If you have to share IRQ's it helps to put two devices that are typically not used at the same time together. and I tend to leave anything out of the PCI slot that shares with the highpoint controller so that IRQ's are not generated to interfere with the disk IO.

Also don't put anything else on the same firewire bus as the monitor as I have seen bugs in the firewire drivers that cause problems with multiple devices on the same bus.

Just some thoughts to try. I can run VV3 and VV4 on my PIII 900mhz laptop through a PCMCIA firewire card into a Canopus ADVC-100 DA converter to a monitor and I get 29.97 fps playback without jerkiness. If I use a filter then it slows down. You also might check the resampling options and the preview quality options. I just use standard preview.

Audio cards can cause latencies. Creative Labs cards are CPU hogs, I avoid them. Hardcore gamers avoid them too. Maybe the newer ones are better but my experiences with them were negative. With my ATI All In Wonder, using creative cards caused the audio to go out of sync with the recorded video very quickly. m-audio works great and they have ASIO drivers and 24/96 playback 5.1 surround sound for 99 bucks or less.

Just some thoughts...

-Dirk

I had the same problem and I have the same motherboard.
Asus p4B533. I did found the problem and works great now.Problem is not Vegas video. It is Asus MB with onboard sound card.I disabled the onboard sound in bios and got my self sound blaster 5.1 and is working great now. I did test the problem with Premiere 6.5 also with same problem. Also I aply the latest driver for onboard sound card with no luck. For some unknown reason onboard sound dos not like to shar IRQ with some of the Firewire cards. So replacing
the sound card took care of the problem.

Hello,

Sounds like we are still trying to drill down to root cause: I also have the ASUS P4B533, with on-board sound and on-board 1394. I'm using seperate Pyro 1394 card with on-board sound and ADVC-100; playback on external TV looks great and is smooth. XP-Pro;BIOS handling IRQ assignment; video files reside on 240gb RAID, system/software/cache on same 7200rpm 80gb WD with 8mb cache; 1.0gb memory. Take care, Kevin.

Jerky playback solved with vegas 4.0b !

:-)))))