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Brent Marks March 17th, 2005 09:36 AM

How can DVRACK capture to a 4200rpm drive? (this is for my personal knowledge base)
How can DVRACK capture to a 4200rpm drive? (this is for my personal knowledge base)

I was reading on their site that it can capture video to disk no problem even with a 4200rpm drive...

How does this work? I always thought I needed a 7200rpm to be safe.
I am curious for my own personal-knowledge-base as to how this is possible.


Benoit Ambry March 17th, 2005 05:22 PM

Actually the speed at which a hard drive spins is not a requirement to record correctly, it is just an indication of the actual preformance of the drive. The faster it spins, the faster it can read and write. But this is just a marketing spin, if I may.
The actual number you want to know, that is never published by hard drive manufacturers, is the speed at which the hard drive reads and writes data. DV requires 25 Mega BITS per sec, that is 3.1 Mega Bytes (Let's say 3.5 with all the extra needed to make it an AVI or a QuickTime clip). As long as your drive can sustain more than this rate then recording will be successful.

Actually a lot of factors play in computing the rate at which a drive can read and write. It's density, geometry, bus speed, rpms all play their role. It ends up beeing almost impossible to give a real number, especially that the rate will vary depending on where the data is located. The best way is to test, but nowadays, most 4200 rpm hard drive will sustain 5 MB/s without a sweat.
On the other end, drive are slow to seek to different locations on the disk, this can make a record fail if a drive is seeking too often (as when your drive is all fragmented). A drive that advertise a 10ms seek time will be able to seek (and just seek) 100 times a sec (3 times a frame). If recording requires seeking more than 2 times per frames, the drive will not be able to sustain the required rate.
Fortunately it is very rare that a drive needs to seek that much and as long as you record on empty space, very little seeking is done.
There's also a special buffer scheme implanted in DV Rack to allow long burst of seeks and slowdowns without loosing recorded data.

There's free tools out there that you can download (sisoftware sandra for example) that can evaluate your drives and tell you how fast they are.

Keep your drive defragmented and all will be fine.

Note also that recording is not all you do with your hard drive. After recording you will playback and scrub your clips, and there seeking is king, so if you want a pleasing scubbing experience, then invest in a fast one.

Chris Hurd March 17th, 2005 05:53 PM

Benoit is quite right (and welcome to DV Info Net, Benoit).

4200rpm is perfectly suitable for straight capture or direct recording from the camera. I've done it myself many times; back when the FireStore FS-1 was new, I worked a trade show exhibit at DV Expo west for Canopus to demo the FireStore and we used a 4200rpm Lacie PocketDrive for that. It performed flawlessly.

On the other hand, DV *real-time editing* generally requires 5400rpm. Most folks these days use 7200rpm drives because they're more affordable now than they were before.

Brent Marks March 21st, 2005 09:49 AM

>>DV rack for HDV?
Does anyone know if/when they will make DVRack for HDV????

It is a fantastic program.... and would love to see it for HDV...


Shannon Rawls March 21st, 2005 10:04 PM

Now THAT WOULD BE SWEET!!! TO be able to capture HiDef .m2t files direct to your laptop computer while connected to a HDV camera...and be able to do the same monitoring that DV Rack provides????

I would be a sure buyer!

- ShannonRawls.com

Brent Marks March 21st, 2005 11:05 PM

What kind of processor speed u think is needed???

Does anyone know if they are working on it???


Christopher C. Murphy March 22nd, 2005 07:19 AM

We've been hounding them for ages now.


Pretty please with sugar on top!


Barry Green March 22nd, 2005 12:39 PM

I'm sure they're working on it. As for processor speed... considering an HDV frame can be 6x as many pixels as an SD frame, I'd imagine that you'll need a massive processor or even dual processors. Or, the alternative is that it'll just run at less performance (i.e., updating the monitor at 10fps, something like that). As long as the recording is flawless (and with the data rate being the same as DV, I'm sure the recording will be the same) I'd live with a slower refresh rate on the monitor for the ability to record HDV to disk.

Brent Marks March 22nd, 2005 01:39 PM

Yeah... have it have the option of full speed with a powerful proc.

or slower refresh for older comps

but recording has to be flawless

Hugh DiMauro March 23rd, 2005 03:14 PM

Hey Brent, can you drop me an e-mail with details extoling the virtues of DV Rack based on your personal experience?


Hugh DiMauro March 23rd, 2005 03:36 PM

Also, if you're using a laptop with 512 mg of ram, make sure you have some space set aside for your page file (that section of your hard drive that is put aside as "ram" to supplement your regular ram which all ads up to "virtual memory". Virtual memory is RAM + Page File = Virtual memory). DV Rack may not capture unless you upgrade your ram chips to 1 GB or supplement your 512 mb with a hard drive page file.

Karl Soule March 24th, 2005 01:32 PM


Pat Sherman April 8th, 2005 07:50 AM

Karl da man..

HDV captures would be sweet, however I would like to before that I would like to see the SD version of it, have a little better project manager interface.

Maybe a menu that spells out where you want to save your clips.. Currently u just right-click anywhere and create a new project on the drive you want, and the clips go there. Just a end-user interface suggestion really..:)

Pat Sherman April 8th, 2005 07:54 AM

Before I bought my new setup I was using DV Rack with a PIII 500MHZ Laptop and the oem system drive at 4200 and it captured fine. Albeit it the menus were not very responsive..

Since them I went to:
IBM Thinkpad X31
Pentium M 1.6
Pyro DV PCMCIA Card W/ 6 Pin and 4 pin DV connections
Onboard 4 Pin DV Connector
I capture to a Lacie 320GB FW drive now..

I did notice that things went alot smoothing connecting the camera to the PCMCIA card and the drive to the laptop 1394 port.. I think maybe because they were using seperate resources..

Pat Sherman April 8th, 2005 08:04 AM

That is totally your call..

I'll start by giving your a little background for my decision. I currently have a full-blown certified Matrox RT.X100 desktop with mega ram, mega hard drive space and a 3.6GHZ processor.. This of course is my main editing system.

I have a second system I initially built a year ago which is a dell optiplex desktop with 500GB HD Editing Space, 1GB Ram, 2.8GHZ processor with the RT.X100 setup. I use this to help teach others how to edit and off-load smaller projects to it when my other system is working a large project. I also use it for my analog conversion system.

So then I stumbled across DV Rack and really I liked it initially because it's a DVR as well.. So it was time for me to get a system for it.. I just purchased a laptop that would double as a standard system for email, internet and photoshop and of course run DV Rack well..

I wasn't interested in editing on the road and frankly I never saw a need for it in my particular situation. So I didn't go with a full blown mobile editing laptop..

My final system for DV Rack:
IBM Thinkpad X31
Pentium-M 1.6Ghz
60GB OS Drive
Ati Graphics
1 OnBoard Firewire Port
1394 Pyro DV PC Card (Dual Firewire Ports)
External Lacie 320GB Firewire Drive

In closing I find this setup sufficient it's not the fastest processor or the best new technology, but it works.. However if DV Rack starts HD captures and I start shooting HD this laptop will not do..:)

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