Slow hard-drive or slow processor?

Hi Everyone,

I haven't started out in DV yet, but I was thinking of getting a dv
camcorder and doing a few home movies, DVD quality, to eventually author it
onto DVD.

Am I right in thinking that it is crucial to have a fast harddrive in order
to capture the video onto, or is a fast processor more important? I
understand that this might be a question about what sort of compression I
will be using - with more compression requiring more processor, but less
harddrive? Can a camcorder run the tape slower to compensate for a slower
hardrive?

Can I get away with the equivalent of a 2GHZ Pentium 4 processor (1.3GHz
Banias) for most compression? What about harddrives? I know that I really
should get an external harddrive, but what speed hard drive is the absolute
minimum? Some laptops have a 4200rpm harddrive, but mine has a 5200rpm
one - will this be better for capture?

I'd like to get away with the bare minimum for capturing and authoring DV -
the camcorder is going to cost enough, and I won't have the money to get
another hardrive straight away.

How important is the video card? I understand it is used somewhere in the
process - is it able to take load off the processor for capturing and
compression? Or is it more for, say, rendering?

And the last question... What is the bare minimum RAM I can get away with
(absolute minimum).

Thankyou all in advance for your anwsers!

Yours,
Duncan.

 

DV compression is fixed - the HD speed will be more important. Get a 7200
RPM HD (the slower ones may work, but 7200 is recommended by most) - just
about anything on the market today will be sufficient.

Your CPU speed will only come into play during recompression or adding
effects.

I've done it with 64MB, I would recommend 128 or more. Presently, I'm
working on 256. As always, the more the better - and RAM isn't that
expensive right now.

 

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http://www.videoguys.com/system.htm

 

Just to clarify - are you saying there's basically no processing required to
capture DV video onto hard disk because it's already compressed and remains
in this same format on the harddrive? I understand that DV is not the same
as MPEG2, though they are supposed to be similar? If I am going to put it
onto DVD, then I presume at some point a conversion will have to take
place - is this what you mean by recompression further down the post?

You say slower ones *may* work - but yes - I've noticed everywhere suggests
7200rpm or above, too. I can't imagine that the speed at which the
camcorder can supply the computer can vary much? And I guess data flow must
be around 400Mbps (the firewire/dv standard)? So presumably the hard drive
must be at least 400Mbps speed in order to cope with all of the information
coming in. Have I got this right?

This is good to know - as I have patience.

Sorry - could you clarify - do you mean video ram or normal RAM? 64MB for
normal RAM seems very small, as does 256MB - I'd be amazed that even the
software could run like this? (Yet the way you have written about RAM being
cheap suggests you're not talking vram) However, if you mean VRAM - am I
stumped because I have only a 32MB card?

Thanks in Advance,
Duncan.

 

Actually, with a PCI bus ATA controller, there is almost no processing
required for a straight DV capture. Yes, the conversion would take place
after the capture - probably, you would capture, then edit in DV, and only
convert the final product for DVD export.

DV runs about 10Mbps. Any ATA-100 or better HD should be able to keep up.
You can also go with SCSI, but it's probably not worth the cost - you get
more storage for the money with ATA. Some 5400 RPM drives have shown to
work, but there's less than $10 difference in the prices between 5400 and
7200 lately, so it's probably not worth taking the chance.

I've done such work with a 200MHz Pentium II - it's nice to have more speed,
but not essential if you don't mind waiting.

I'm talking about system RAM. The system I'm running right now has 256MB,
and works fine. Of course, the rule with RAM is always "get as much as you
can afford". The system I'm building has 1GB...

32MB for a video card should be fine - my current system only has 16MB and
works fine. Again, more would be fine, if you can afford it, but if not,
you're good with what you have.

 

You need a sufficiently fast drive and a sufficiently fast processor.
If you are capturing DV over Firewire, you basically need a bit over
3 Mbytes/sec and probably a Pentium 90 is sufficient. Current high
capacity 7200 RPM hard drives can sustain over 20 Mbytes/sec across
the entire disk.

Most camcorders can not do DV capture at anything other than real time.

Laptop hard drives are a lot slower than desktop hard drives. The RPM
is only loosely related to the sustained write performance of
a hard drive--higher RPM generally means the drive was targeted at
higher performance markets at the time the drive was introduced--but
it by itself doesn't tell us the absolute performance of the drive.

You don't need much memory at all for capture.

If cost is important to you, then don't use a laptop. If you already
have a laptop, then go ahead and use it, but you may want to use an
external hard drive based on a desktop drive.

 

First thing you need is a DV connector to get the DV stuff into your
harddrive. Fireware cards, and some graphic and capturing cards,
provide that. So get that, and try it. You may not need any other
hardware. The 3,2 MB/s bitrate of DV is low, and your harddrive may
very well cope with it. Do first things first, and come back if
problems arise.

 

Thankyou all for your help - you've cleared up a lot of things for me -
cheers!

Duncan.