Hi,

I am a newcomer to dv editing and audio. I urgently need to edit a short
film for a show in Aug and need to setup a make-shift pc for editing as I
can't afford the computer I want just yet, and will do this mostly from the
bits and pieces I have kicking about.

I have
a pinnacle studio DV capture card
a geforce 2 MX400 AGP card
an old abit SL6 motherboard (solid board but only goes up ata66 and 512mb
sdram)
a pIII 800mhz
a celeron 500mhz
an athlon 1100 mhz

I am buying a 120gig ata133 7200rpm IBM/Seagate drive, and may buy a smaller
one for C: drive. This is so I can hang on to them when I get a good system.

I am wondering whether, if I was to make do with the Abit board, I could get
a PCI raid card to get the 2 hd's transferring quicker. I don't really know
anything about raid - could someone please explain what its all about?

Would I be better to replace the motherboard with one that allows ata100?

Any help would be much appreciated

Andy

I am a newcomer to dv editing and audio. I urgently need to edit a short
film for a show in Aug and need to setup a make-shift pc for editing as I
can't afford the computer I want just yet, and will do this mostly from the
bits and pieces I have kicking about.

I have
a pinnacle studio DV capture card
a geforce 2 MX400 AGP card
an old abit SL6 motherboard (solid board but only goes up ata66 and 512mb
sdram)
a pIII 800mhz
a celeron 500mhz
an athlon 1100 mhz

I am buying a 120gig ata133 7200rpm IBM/Seagate drive, and may buy a smaller
one for C: drive. This is so I can hang on to them when I get a good system.

I am wondering whether, if I was to make do with the Abit board, I could get
a PCI raid card to get the 2 hd's transferring quicker. I don't really know
anything about raid - could someone please explain what its all about?

Would I be better to replace the motherboard with one that allows ata100?

The Abit with the 7200rpm drive will be quite adequate for capturing
or sending one stream of DV. This is the only place performance is
critical. A faster system would render the finished video file
faster. So what?
The Pinnacle card is just a FireWire port. It will do this just as
well (but no better :-) than the one available from Dabs for £9.99
including cable.


Any special reason you have to make up a dedicated computer? What are
you writing this message on?

RAID needs two identical drives. It is inappropriate in this case. I
can think of few single-user applications where it IS necessary. It's
probably appearing on all new motherboards today because the function
is integrated into a chip that does something more useful :-)

This question of HD speed is an interesting one.

I know most manufacturers recommend a separate one for video and in the case
of my system with a RT2500 (Matrox card) they recommend splitting the audio
from the video entirely.

I know there are some proponants of the single drive system but is it not
true that the more layers of video you work with, the more demand is placed
on the HD right?

I.e If you have two video streams one on top of the other both with audio
and going to put double the demand on the HD transfer rates?





"Young" wrote in message
...
Hi,

I am a newcomer to dv editing and audio. I urgently need to edit a short
film for a show in Aug and need to setup a make-shift pc for editing as I
can't afford the computer I want just yet, and will do this mostly from
the
bits and pieces I have kicking about.

I have
a pinnacle studio DV capture card
a geforce 2 MX400 AGP card
an old abit SL6 motherboard (solid board but only goes up ata66 and 512mb
sdram)
a pIII 800mhz
a celeron 500mhz
an athlon 1100 mhz

I am buying a 120gig ata133 7200rpm IBM/Seagate drive, and may buy a
smaller
one for C: drive. This is so I can hang on to them when I get a good
system.

I am wondering whether, if I was to make do with the Abit board, I could
get
a PCI raid card to get the 2 hd's transferring quicker. I don't really
know
anything about raid - could someone please explain what its all about?

Would I be better to replace the motherboard with one that allows ata100?

Any help would be much appreciated

Andy

In message , Steve Franklin
writes

Snipped...

This question of HD speed is an interesting one.

I know most manufacturers recommend a separate one for video and in the case
of my system with a RT2500 (Matrox card) they recommend splitting the audio
from the video entirely.

I know there are some proponants of the single drive system but is it not
true that the more layers of video you work with, the more demand is placed
on the HD right?

I.e If you have two video streams one on top of the other both with audio
and going to put double the demand on the HD transfer rates?

There's been much discussion of this subject here (and elsewhere).

To put it all into perspective all you have to do is to take the *very*
maximum HDD read/write requirement - that with raw or AVI DV - of about
3.6Mb/s and compare that with the buffered read/write benchmarks of even
modest 5,400rpm drives. You'll find that even in the worst possible case
scenario you have headroom of about 5x .

The real problem with video work is associated with the way that PCs use
virtual (disk) memory when the conventional memory becomes short. This
problem is best addressed - not by treating the symptoms - but by
attending to the cause. The cause can be easily recognised by running
Computer Management/Services to see the very considerable demands placed
on conventional memory by all these processes. Add this demand to that
of video programs you're running (which are run from memory) and you can
start to recognise where the *real* bottleneck is. And adding a second
hard drive does little to alleviate this bottleneck - in spite of what
many folk will assert.

--
Tony Morgan
http://www.camcord.info

Snipped...

This question of HD speed is an interesting one.

To put it all into perspective all you have to do is to take the *very*
maximum HDD read/write requirement - that with raw or AVI DV - of about
3.6Mb/s and compare that with the buffered read/write benchmarks of even
modest 5,400rpm drives. You'll find that even in the worst possible case
scenario you have headroom of about 5x .

The real problem with video work is associated with the way that PCs use
virtual (disk) memory when the conventional memory becomes short. This
problem is best addressed - not by treating the symptoms - but by
attending to the cause. The cause can be easily recognised by running
Computer Management/Services to see the very considerable demands placed
on conventional memory by all these processes. Add this demand to that
of video programs you're running (which are run from memory) and you can
start to recognise where the *real* bottleneck is. And adding a second
hard drive does little to alleviate this bottleneck - in spite of what
many folk will assert.

But since Windows (and I assume we are talking about Windows) uses the disk
for virtual memory, then anything which speeds up the disk access speeds up
everything else. That "headroom" of 5x is not so great if the virtual memory
paging really needs more than 4x of the 5x (if you get my drift) ...

On mainboards which have RAID (or when you have a RAID controller card) then
it is possible to configure (at least) 2 hard drives in an array to
effectively nearly double the speed of one. The question is, does this
speed up video editing? Well, clearly it must, even if the RAID array merely
handles the Windows swapfile. Whether or not it does when handling the
source and destination video files, must depend on a lot of factors, such as
their size and the configuration of the rest of the machine. However, 2
drives of (say) 30Gb in the correct type of RAID array will give you a
significantly faster equivalent disk than one drive of 60Gb capacity
(configure the RAID another way, and you get 1x30 Gb, and no speed increase,
but total security by mirroring - configure it another way, and you get the
full capacity, nearly double the speed, and no security. The second way is
the "right" way for temporary files).

Clearly also, bucket loads of real RAM (and an OS which handles it
effectively) and a fast cpu are also parts of the process.

In my (limited) experience, the one thing that does rely on you to just
leave the machine alone for an hour or two to get on with it is rendering
the final video, which may involve changes of resolution and on the fly
compression. On my 1.4 Athlon, this takes about 3 times as long as the
length of the video (e.g. 20min video takes getting on for an hour).

But since Windows (and I assume we are talking about Windows) uses the disk
for virtual memory, then anything which speeds up the disk access speeds up
everything else. That "headroom" of 5x is not so great if the virtual memory
paging really needs more than 4x of the 5x (if you get my drift) ...

What do you feel the swapfile will be used for? Video is all about
streaming large amounts of data on and off disk. There's no point in
getting it off disk only in order to cache it in a swapfile
.....er....on disk :-)

While editing, you may access two or (rarely) more streams fron disk.
You monitor at preview quality, and if the preview glitches, it
doesn't matter :-)

The final rendering takes as long as it needs to. Disk speed
irrelevant, except to get the job done a bit quicker.

I don't think any of us are attempting online video editing at home?
That's where speed of multiple video streams in and out of the machine
become an issue. Maybe next year :-)

However, don't you think it much simpler and far less expensive to treat
the cause (before doing any video work) by closing/kiilling all those
background processes which force your PC into VM? It takes only a few
seconds.

Really, swapping programs in and out of memory is ancient history.
From way before the days when we could dream of proper video editing
on a computer.

Personally I find things run OK if you have a separate (from OS and
editing app) drive, preferably 7200rpm and defragged with NTFS, to
capture the video onto. And as editing apps can be a bit memory hungry,
using something like EndItAll2 to get rid of any little programs hanging
around. This does tend to make things a bit easier/stable when you come
to rendering. Oh and when rendering, just leave the app to it for a while.

Both of these have been suggested in this thread already I know, but
from a rather basic level you should be OK if you do something similar.
It works for me!

wrote:
However, don't you think it much simpler and far less expensive to treat
the cause (before doing any video work) by closing/kiilling all those
background processes which force your PC into VM? It takes only a few
seconds.


Really, swapping programs in and out of memory is ancient history.
From way before the days when we could dream of proper video editing
on a computer.

What do you feel the swapfile will be used for? Video is all about
streaming large amounts of data on and off disk. There's no point in
getting it off disk only in order to cache it in a swapfile
....er....on disk :-)

Well, if you know in detail what Windows does, and can guarantee never to
use a swapfile, then fine. I find Windows does what it wants, and if it
wanders off and wants to use its swapfile, then it tends to do so without
asking my permission! There's lots of things in Windows to which one might
say "There's no point in ..." - but they are there!

While editing, you may access two or (rarely) more streams fron disk.
You monitor at preview quality, and if the preview glitches, it
doesn't matter :-)

Yep, preview quality *always* stutters because the rendering is slower than
real time.

But the computer is doing more than copying one video stream to another. It
may be merging an overlaid sound track. It may be merging two (or more)
video streams. It may be applying some transition and/or other effect. And
it may be doing the compression implied by an AVI (source) to MPEG-II
(destination) transformation. Note that AVI is, in any case, a somewhat
compressed format, and needs decompressing. In memory at any time a the
OS, disk cache space, the application code, the workspaces, however many
frames and seconds of sound it needs, etc etc etc. This memory usage is
varying in time, for example, you need less space if you aren't applying any
visual effects. What happens if you don't have enough physical ram at any
moment in time? ... that's when the swapfile comes in. If you don't have a
swapfile, the program stalls or the machine hangs. If you have a swapfile,
the whole deal runs slow for a while. How slow depends on how fast the disk
is..... I can tell you don't believe me, even before I post this. So I did a
test.

It is possible to monitor swapfile usage using SYSMON. Just to check whether
my machine does use the swapfile, I opened an AVI, and asked for it to be
rendered to MPEG-II. No funny stuff like dubbed music, transitions, etc.
Just a straight conversion. I have 512 Mb of RAM, and had Outlook Express
(and this post) open as well as SYSMON. I'm using Dazzle Movie Star 5. The
first thing that happened in the SYSMON screen was that Windows (98se)
enlarged the swapfile to over 200 Mb. Then, as the first 25 sec of the video
was converted and compressed the amount of free physical RAM decreased
progressively. At this point, SYSMON reported a non-zero use of swapfile.
With time, the used swapfile space grew and grew until I got bored and
switched it off. The used swapfile was up to about 10Mb by then, and if it
continued to grow with time, then filling the 200 Mb probably isn't out of
the question. What with? That beats me!

Now I am prepared to concede that with a different amount of RAM, different
package, etc etc, there could be a situation where the swapfile wasn't used.
But on my machine, it does get used. Once the swapfile is in action, it
controls the overall speed of the process and rendering slows down.

The final rendering takes as long as it needs to. Disk speed
irrelevant, except to get the job done a bit quicker.

And when disk speed controls the overall speed of a process, then doubling
it by use of a RAID striped array is a useful thing to do.

Cost of 2 Maxtor 7200 30Gb drives from www.redstore.com = GBP76, and that's
it if you have RAID onboard already (add-on controller cards are a bit
pricey, granted). You don't get much increase in cpu speed for that money.

I don't think any of us are attempting online video editing at home?
That's where speed of multiple video streams in and out of the machine
become an issue. Maybe next year :-)

If it is just a question of viewing several video streams, and deciding in
real time which one to pipe into an output, then I'm prepared to bet that a
reasonable modern PC could take it in its stride. Convert it from one format
to another? That's what chokes it.

"Young" wrote in message
...
Hi,

I am a newcomer to dv editing and audio. I urgently need to edit a short
film for a show in Aug and need to setup a make-shift pc for editing as I
can't afford the computer I want just yet, and will do this mostly from
the
bits and pieces I have kicking about.

I have
a pinnacle studio DV capture card
a geforce 2 MX400 AGP card
an old abit SL6 motherboard (solid board but only goes up ata66 and 512mb
sdram)
a pIII 800mhz
a celeron 500mhz
an athlon 1100 mhz

I am buying a 120gig ata133 7200rpm IBM/Seagate drive, and may buy a
smaller
one for C: drive. This is so I can hang on to them when I get a good
system.

I am wondering whether, if I was to make do with the Abit board, I could
get
a PCI raid card to get the 2 hd's transferring quicker. I don't really
know
anything about raid - could someone please explain what its all about?

Would I be better to replace the motherboard with one that allows ata100?

Any help would be much appreciated

Andy

RAID 0 - Not really a RAID (the "R" stands for "Redundant") simply a way of
increasing potential disk throughput - potentially, if you have 'n' disks,
then assuming similar disk performance of x Mbyte/sec per disk, then your
aggregate I/O rate is potentially n * x Mbyte/sec. Downside is, if a disk
goes down, you CANNOT recover all your data.

RAID 1 (aka "mirror") assumes that you have two disks with an aggregate
capacity of the smaller of the two disks. If you lose one disk, you still
have all the data on the other disk. No I/O rate increase.

RAID 5 you lose one disk's worth of aggregate capacity and you need at least
three disks, BUT if one disk goes down, it is still possible to reconstruct
the data from the parity data held on the other disks of the array. I/O
performance approaches x * n for larger n.

However, most modern disks are not going to be worried by the sub 4Mbyte/sec
rates of DV capture, so unless you are /really/ worried about losing the
data once it is on disk, I wouldn't bother with RAID - remember, you're
almost always going to have the original data on the source tape.

PeterS