dropping frames

[unc417]

I have a PD170 cam connected to a computer via firewire. The computer drops frames every time I try to get a recording. It's not completely random as to the number of dropped frames, it's usually one of a few numbers that I keep seeing over and over.

The computer was donated but I put a new mobo/cpu/ram in it. It runs xp.

During recording it freezes up for a second or a few seconds. If you are watching the screen when it happens you notice that the video stops moving, when the video starts to move again it registers dropped frames.

I'm not sure how to proceed troubleshooting an issue like this.
Thanks

[petereit]

Dropped frames are almost always due to hard drive write speed too slow to keep up with the massive amount of data that is live video.

1. Make sure you're not capturing video to your system drive. If Windows access OS files during your capture (and it will!) drive contention will really drop your write speed.
2. Make sure you keep your capture drive under 75% full and defrag it regularly.

[unc417]

I was capturing to the same drive as the system, I know it's not ideal but it's never caused problems. But to fix that I bought a new drive and installed it as a secondary drive, it still dropped frames today.

Also a correction, it runs 7 not xp.

[petereit]

Download BlackMagic Design's free drive speed monitoring program and use it to test the speed of your drive. It will tell you how fast your drives need to be to capture various resolutions and frame rates.

If you're trying to capture high-definition video, you either need somethng like a 10,000 RPM Velociraptor drive, or you need to combine two (or more) normal drives in a RAID0 configuration that doubles your effective write speed.

We have three 1TB Hitachi drives combined in a RAID0 configuration in our Mac Pro to give us the speed needed to capture live 720p/60.

[unc417]

I'm recording SD.

That software doesn't work for 64bit and I couldn't find another version of it.

I used crystal disk tester and it showed 128MB/sec and 106MB/sec write. Seems that should be enough to record 3.75MB/sec coming in on the firewire. (I know avi is 30mbit/sec so I assume that's what's coming in from the cam???)

[petereit]

Could be hardware-related: RAM, overheating CPU, failing HD controller, mis-seated PCI card, bad cable or connectors between your camera and PC, or even a cable/connectors that don't meet the technical specs for your transmission method.