How important is Hard Drive speed for Digital Video work?

[backpackerx]

I'm looking into getting a new computer and would like to do some DV work on it. How important is Hard Drive Speed for digital video work? Most of the drives are 7200 RPM if I'm not mistaken but I saw a good deal on a laptop with only a 4200 RPM drive and wondered if that would cause a problem.
Anyone using a 4200 drive for DV work?

[Crocuta]

I'm looking into getting a new computer and would like to do some DV work on it. How important is Hard Drive Speed for digital video work? Most of the drives are 7200 RPM if I'm not mistaken but I saw a good deal on a laptop with only a 4200 RPM drive and wondered if that would cause a problem.
Anyone using a 4200 drive for DV work?

In theory, there's no reason such a drive cannot work for DV transfers. Your drive must support a sustained data transfer rate of 3.7 MB/s and almost any drive out there will do that. (Most current drive perform at well over 30 MB/s.) If you can, you may want to test this with the specific system in question. With this being at the slow end of the curve these days, it wouldn't hurt to make sure it will work before laying down the cash.

Probably the worst thing about this setup is that you'll probably be using the same disk for your system as for your capture. That's not to say this cannot work, but it's one of the areas that often cause trouble for people. Ideally, you would want two IDE channels with one drive on each, one the system drive and one the capture drive. Some people say they use one drive without problems and so it's certainly possible, but some people also have problems that seem to be solved by rearranging their systems that way.

Good luck whatever you decide.

[Jason Dunn]

I used a 4200 RPM in an external Firewire enclosure, and used Scenealyzer to do a speed test, and it tested 3x realtime - meaning I had three times more speed that I needed to capture full stream DV in real time. By comparison, a 7200 RPM Western Digital drive over USB 2.0 ranked 7x realtime.

More speed is always better, but 4200 RPM is workable!

[Crocuta]

I used a 4200 RPM in an external Firewire enclosure, and used Scenealyzer to do a speed test, and it tested 3x realtime - meaning I had three times more speed that I needed to capture full stream DV in real time. By comparison, a 7200 RPM Western Digital drive over USB 2.0 ranked 7x realtime.

More speed is always better, but 4200 RPM is workable!

Great point, Jason. And for a notebook, if it has a Firewire port, an external Firewire drive might be just thing to get past the issue of having a single set of heads trying to run the OS and the capture program and write a continuous stream of DV data at the same time.

[backpackerx]

Well, I did some capture to my current laptop which is a 900Mhz Pentium 3 with 256Mb RAM. I'm using a firewire PCMIA card in my notebook and the video came out a little choppy in some places, mainly at the beginning of the session like it was trying to "catch up".

The thing is, I was monitoring my CPU and memory usage and the CPU never went over 30% and the memory was less than half utilized so it *seemed* like this wasn't overwhelming my older system. Are there other reasons why captured video comes out a little choppy?

Also, it seems like the refresh rate on the screen isn't to good because I noticed blurring on my laptop while panning that isn't there on the TV. Anyone know what a needed refresh rate for clear video is?

Thanks

[backpackerx]

2nd question.

I'm looking at getting an external hard drive but putting one together to save money. What kind of enclosures and cables do I need to build a regular internal HD into a USB or Firewire external hardrive?

Also, is USB 1.0 fast enough for an external hard drive?

[Crocuta]

2nd question.

I'm looking at getting an external hard drive but putting one together to save money. What kind of enclosures and cables do I need to build a regular internal HD into a USB or Firewire external hardrive?

Also, is USB 1.0 fast enough for an external hard drive?

There are tons of drive enclosures available these days. Here's a site that has a wide selection. http://www.cooldrives.com/

USB 1.0 definitely won't be fast enough as its top speed is less than that of DV capture. Both USB 2.0 and Firewire are plenty fast enough for DV capture, though Firewire is better suited to the task so get that if you have a choice at the same or similar price. Don't sweat it, though, if you need to go USB 2.0. Firewire's advantages are marginal and both support transfers at speeds significantly higher than needed by DV capture.

[Gary Sheynkman]

Faster is better but RPM is not the only thing you should look at. Cache and other specs are important.

[backpackerx]

Thanks, that'll give me a better idea of what I'm looking for.

[Jason Dunn]

Well, I did some capture to my current laptop which is a 900Mhz Pentium 3 with 256Mb RAM...Are there other reasons why captured video comes out a little choppy? Also, it seems like the refresh rate on the screen isn't to good because I noticed blurring on my laptop while panning that isn't there on the TV. Anyone know what a needed refresh rate for clear video is?

Assuming you're running Windows XP, 256 MB of RAM will contribute to the problem - Windows XP takes up almost that much sitting idle. 512 MB is a safe zone for video capture.

Did you disable all other programs on the laptop, including any anti-virus programs you might have running?

Were you capturing to an empty partition, or your main internal hard drive? That's the #1 cause of bad captures - capturing to a fragmented hard drive full of data.

Regarding the refresh rate, I'm not sure - I haven't had that problem with LCD screens in a few years, but I don't know the refresh rate of my screens off hand.

[backpackerx]

Actually, I'm still running 2000 :oops: Oh well, it's a free laptop from work so I can't complain. Yes, I was capturing to a main hard drive so that could be the problem. I'm looking at an external solution but I only have USB 1.0 so I'd either need to capture to the main drive and transfer :( or buy a PC card with USB 2.0.

Do they make laptop card extenders? As it is now, with the bulk of my firewire card I can't use my WiFi card at the same time or a future USB 2.0 card. If I could extend one of them a little I would get the extra clearance.

[Jason Dunn]

You're trying to do WiFi while doing video capture? I think you need to take a big step back. :-)

Your best bet would be to get a Firewire or Firewire/USB 2.0 combo card - plug the camera into the Firewire port, then the external hard drive into the other. These cards aren't cheap though!

Or consider getting a desktop computer that would make this all easier. ;-)

[backpackerx]

lol, no, I have a firewire card for capturing my video and need a USB 2.0 for the hard drive and burner I'm looking at. I was just using the WiFi card as a reference, meaning I can't use two cards at the same time due to the space. I know I can get a combo card, I just didn't want to waste the firewire card I just bought.

The problem I was referring to would prevent the firewire card and the USB card from being used at the same time because of the bulk of each and the spacing of my notebook slots.

[Jason Dunn]

Ok, so I'd suggest that you get an external drive that can use both Firewire and USB 2.0, then use it in Firewire mode to capture the video straight to the drive. I'm assuming has more than one Firewire port of course (most do). I've done exactly this on a 750 mhz laptop, and it worked out quite well - no dropped frames.