Dropped frames, Mac or PC difference?

[Darryn Carroll]

Can anyone confirm that a Mac will suffer less dropped frames than a PC during dv tape ingestion? I have a friend who insists this a fact.

[Eric Olson]

Originally Posted by Darryn Carroll

Can anyone confirm that a Mac will suffer less dropped frames than a PC during dv tape ingestion? I have a friend who insists this a fact.

Neither Windows nor OS X offer guaranteed interrupt service latencies so dropped frames are possible when either system is loaded with other tasks. Given the way Windows allocates resources to make mouse driven applications more responsive, simultaneous websurfing while capturing a tape is more likely to result in dropped frames on Windows than on OS X. If you are doing things properly, neither system will suffer any dropped frames except the ones caused by defects on the original tape.

[Paul Wags]

I have firewired from 3 Mini DV cameras at the same time on my old XP PC :-)
If it's missing then your system is not set up correct.

[Darryn Carroll]

Thanks Paul, I just cant figure out my "trigger". I shut down as many backgrounds apps I can find, shut down antivirus, did a complete defrag and then I ingest via firewire. Yesterdays experiment had me ingest the same 60 minute tape 3 times and had 55, 77 and 122 dropped frames in different places. Laptop is a 2.4 ghz, 8 mb ram, 64 bit Windows 7. Captured with Sony Vegas and Roxio Capture. Any thoughts?

[Luke Arndt]

Dropped frames had long been a problem for me, until I found ScenalyzerLive 4.0. Not exactly sure what it does, but it is extremely hard to drop frames now. In the past, I would occasionally drop frames even when the computer was idling (except for capture, of course) with nothing else running. I would be way more likely to drop frames if I was actually using the computer at the time.

In the past, I've used the Vegas Video capture tool, WinDV, and Exsate DV Capture Live. Scenalyzer is by far the best when it comes to dropping frames.

For reference, I'm using a laptop with an Intel Core 2 Duo T7300 at 2.0 GHz with 3 GB RAM. Running XP Pro. Have two HDs, a 7200 RPM 160 GB C: drive, and a 640 5400 RPM D:, which is my capture drive.

If you can find Scenalyzer, I bet you'd have a much easier time capturing!!

[Eric Olson]

Originally Posted by Darryn Carroll

Any thoughts?

Turning off antivirus was a good idea. Also turn off "automatic power saving" modes. With 8GB of ram as a buffer, your HD may be spinning down in the middle of capture. Finally check for alternative drivers for your firewire ports. I've heard discussion that the "legacy" drivers work better with some software.

There is also a possibility your firewire port is defective. I can capture DV and HDV source using a 10 year old 650Mhz PIII with no dropped frames. This is done using the dvgrab software running under Linux. If you want to check your hardware, you could set up a dual boot Linux partition. This would provide a completely independent software environment for testing your hardware.

[Jeff Donald]

Other things not mentioned are the speed of the drives. Ideally they should be 7200 RPM drives and not the slower 5400 RPM drives. Avoid the "Green" drives as they will try to power down more often to save energy. Depending on the software used, more ram can help, but you may be maxed at 8 GB.

How full are the drives you're going to? Once you get past 50% full the transfer rate slows significantly. If you have several spare drives, you could try making a software RAID. This can help, but can cause its own issues as well. I'm not sure how to check on a PC, but shut down as many background applications as possible. You can even try disconnecting the computer from the internet to avoid additional disk activity that may be taking place in the background.

I worked for Apple Inc for several years and there is no truth to the statement that Macs will drop less/no frames.

[Luke Arndt]

Darryn, did you ever have any success in getting rid of dropped frames?

[Chris Medico]

One of the first things to do is to buy a new firewire cable. I had tons of problems years ago with random dropouts and it turned out to be my cable. It looked fine with no signs of abuse but I couldn't do full tape captures with it. It would be fine for a minute or two but after that I would get little glitches here and there. I bought a new $10 cable and I could capture full tapes without a problem.