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uk.tech.tv.video.pvr Personal Video Recorder (PVR) (uk.tech.tv.video.pvr) Hard disk-based Personal Video Recorder(PVR) systems.

Computer bottlenecks



 
 
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  #1  
Old February 15th 04, 06:33 AM posted to uk.tech.tv.video.pvr
Richard Brooks
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Posts: 4
Default Computer bottlenecks

Which change in a computer setup would give less capture frame dropouts at
25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?
As much RAM as possible ?
A more expensive capture card than a cheap 40 Winfast TV2000XP ?

I assume all the above but I want to pick one option first and see the
results due to financial constaints.

Many thanks,


Richard Brooks.




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  #2  
Old February 15th 04, 10:58 AM posted to uk.tech.tv.video.pvr
Terry Eden
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Posts: 26
Default Computer bottlenecks

Richard Brooks wrote:
Which change in a computer setup would give less capture frame
dropouts at 25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?
As much RAM as possible ?
A more expensive capture card than a cheap 40 Winfast TV2000XP ?


RAM. Your hard drive speed (assuming it's ATA100 or better) is going to be
just fine for taking video. The card is the most important bit of all - but
assuming it's up to the rw task of capturing the images (i.e. doens't relie
on your CPU), it's going to need somewhere very very fast to stare and
manipulate the data.

Terry

--
--
small disclaimer - speaking for myself, not my employer.


  #3  
Old February 15th 04, 12:04 PM posted to uk.tech.tv.video.pvr
Steve
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Posts: 444
Default Computer bottlenecks

"Terry Eden" wrote in
:

Richard Brooks wrote:
Which change in a computer setup would give less capture frame
dropouts at 25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?
As much RAM as possible ?
A more expensive capture card than a cheap 40 Winfast TV2000XP ?


RAM. Your hard drive speed (assuming it's ATA100 or better) is going
to be just fine for taking video. The card is the most important bit
of all - but assuming it's up to the rw task of capturing the images
(i.e. doens't relie on your CPU), it's going to need somewhere very
very fast to stare and manipulate the data.


Surely, whether you have 256M or 1G, once the ram is full then the other
limiting factors take effect, therefore you may get a longer initial period
before dropping frames then they drop at the same rate.

Now RAM speed is important and may be limited by the motherboard. What
speed is the current RAM, what can the mobo support.
,

Again, I would not be so sure about the capture card, aren't "dropped
frames", frames that were avaialable to the system from the card but not
processed in time (willing to be corrected on this).

Things for the OP to look at if not done already would be to see what CPU
usage is occuring, seeing it anything else is running, turning off anti-
virus software, defragging the disc, having a dedicated partition for
capture,
  #4  
Old February 15th 04, 03:04 PM posted to uk.tech.tv.video.pvr
Terry Eden
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Posts: 26
Default Computer bottlenecks

Steve wrote:
"Terry Eden" wrote in
:
RAM. Your hard drive speed (assuming it's ATA100 or better) is going


Surely, whether you have 256M or 1G, once the ram is full then the
other limiting factors take effect, therefore you may get a longer
initial period before dropping frames then they drop at the same rate.


Naturaly - but 128MB + 1GB Virtual mem is not going to be as good as 0.5GB
RAM. I know from experience that plonking as many DIMMs in as possible
helps any system fly.

Now RAM speed is important and may be limited by the motherboard. What
speed is the current RAM, what can the mobo support.


Very true.

Again, I would not be so sure about the capture card, aren't "dropped
frames", frames that were avaialable to the system from the card but
not processed in time (willing to be corrected on this).


I don't know the card he's talking about. But the cheapo one I had worked
well enough given enough RAM.

Things for the OP to look at if not done already would be to see what
CPU usage is occuring, seeing it anything else is running,


Yup yup yup

turning
off anti- virus software,


Setting the AV software not to scan *.whatever-format-the-software-uses
would be more sensible.

defragging the disc,


Yup

having a dedicated partition for capture,


Probably better to have a seperate physical disc. If possible alone on a
ATTA cable, rather than master/slave.

Terry

--
--
small disclaimer - speaking for myself, not my employer.


  #5  
Old February 15th 04, 04:09 PM posted to uk.tech.tv.video.pvr
Steve
external usenet poster
 
Posts: 444
Default Computer bottlenecks

"Terry Eden" wrote in
:

Steve wrote:
"Terry Eden" wrote in
:
RAM. Your hard drive speed (assuming it's ATA100 or better) is
going


Surely, whether you have 256M or 1G, once the ram is full then the
other limiting factors take effect, therefore you may get a longer
initial period before dropping frames then they drop at the same
rate.


Naturaly - but 128MB + 1GB Virtual mem is not going to be as good as
0.5GB RAM. I know from experience that plonking as many DIMMs in as
possible helps any system fly.


I would hope decent capture software can be told how big to make their
buffers. But yes avoiding swapping is a must (I forget about things like
that as I just throw memory at systems).

Now RAM speed is important and may be limited by the motherboard.
What speed is the current RAM, what can the mobo support.


Very true.

Again, I would not be so sure about the capture card, aren't "dropped
frames", frames that were avaialable to the system from the card but
not processed in time (willing to be corrected on this).


I don't know the card he's talking about. But the cheapo one I had
worked well enough given enough RAM.

Things for the OP to look at if not done already would be to see what
CPU usage is occuring, seeing it anything else is running,


Yup yup yup

turning
off anti- virus software,


Setting the AV software not to scan
*.whatever-format-the-software-uses would be more sensible.


True, I just ignore certain drive letters - but it would be safer to do
as you say.

defragging the disc,


Yup

having a dedicated partition for capture,


Probably better to have a seperate physical disc. If possible alone
on a ATTA cable, rather than master/slave.


Depends on what other things are going on at the time. The aim is to
enable the file to be written contiguously.

I have seperate disc for processing files though, i.e read from one,
write to another - but overkill for overnight processing. I'll have to
check they are on different channels though thanks for the reminder.

  #6  
Old February 15th 04, 07:24 PM posted to uk.tech.tv.video.pvr
Richard Brooks
external usenet poster
 
Posts: 4
Default Computer bottlenecks

Steve wrote:
"Terry Eden" wrote in
:

Richard Brooks wrote:
Which change in a computer setup would give less capture frame
dropouts at 25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?
As much RAM as possible ?
A more expensive capture card than a cheap 40 Winfast TV2000XP ?


RAM. Your hard drive speed (assuming it's ATA100 or better) is going
to be just fine for taking video. The card is the most important bit
of all - but assuming it's up to the rw task of capturing the images
(i.e. doens't relie on your CPU), it's going to need somewhere very
very fast to stare and manipulate the data.


Surely, whether you have 256M or 1G, once the ram is full then the
other limiting factors take effect, therefore you may get a longer
initial period before dropping frames then they drop at the same rate.

Now RAM speed is important and may be limited by the motherboard. What
speed is the current RAM, what can the mobo support.
,


IIRC it's all 133 as it was going really cheap. I've got a dual Pentium III
and after some bad times with newer cards, now wish that I'd got hold of the
Digital DPS 3100 capture card for my old legacy pc, if it's sister the DPS
PAR card, which is sitting all alone in my shed was anything to go by. It
had it's own EISA controller and you could throw bricks at it without it
crashing. Sound was a thing of the future though!

Do many capture cards have their own controllers nowadays ?

Again, I would not be so sure about the capture card, aren't "dropped
frames", frames that were avaialable to the system from the card but
not processed in time (willing to be corrected on this).


I was wondering this and was thinking of uprating to a 10k spindle speed
drive to dump frames to, if this was the issue.


Things for the OP to look at if not done already would be to see what
CPU usage is occuring, seeing it anything else is running, turning
off anti- virus software, defragging the disc, having a dedicated
partition for capture,


That's a good idea - I had overlooked the anti-virus software!

Many thanks to all and I look forward to reading all future tips on cards
etc,


Richard.



  #7  
Old February 15th 04, 07:56 PM posted to uk.tech.tv.video.pvr
Richard Brooks
external usenet poster
 
Posts: 4
Default Computer bottlenecks

Terry Eden wrote:
Steve wrote:
"Terry Eden" wrote in
:
RAM. Your hard drive speed (assuming it's ATA100 or better) is
going


Surely, whether you have 256M or 1G, once the ram is full then the
other limiting factors take effect, therefore you may get a longer
initial period before dropping frames then they drop at the same
rate.


Naturaly - but 128MB + 1GB Virtual mem is not going to be as good as
0.5GB RAM. I know from experience that plonking as many DIMMs in as
possible helps any system fly.

Now RAM speed is important and may be limited by the motherboard.
What speed is the current RAM, what can the mobo support.


Very true.

Again, I would not be so sure about the capture card, aren't "dropped
frames", frames that were avaialable to the system from the card but
not processed in time (willing to be corrected on this).


I don't know the card he's talking about. But the cheapo one I had
worked well enough given enough RAM.


Sorry Terry, I was talking in general terms at first but now I can come
clean.

Initially I had been trying to get a cheap WinFast 2000XP card running on my
VIA chipset dual Pentium III but had lock-up's. This has now been sorted
and it runs well, as well as a free WinTV-pci card that was in a pc that was
chucked out.

I did have a 500+ card that would just do a hard reset and nothing else and
after useless support, the company went bust taking my card with it.


Things for the OP to look at if not done already would be to see what
CPU usage is occuring, seeing it anything else is running,


Yup yup yup

turning
off anti- virus software,


Setting the AV software not to scan
*.whatever-format-the-software-uses would be more sensible.

defragging the disc,


Yup

having a dedicated partition for capture,


Probably better to have a seperate physical disc. If possible alone
on a ATTA cable, rather than master/slave.


That's what I was thinking of and all the above taken note!


Richard.





Terry

--



  #8  
Old February 16th 04, 05:18 PM posted to uk.tech.tv.video.pvr
nick
external usenet poster
 
Posts: 149
Default Computer bottlenecks

get a proper mpeg2 capture card or usb2 device.
(or get a faster cpu)

"Richard Brooks" wrote in message ...
Which change in a computer setup would give less capture frame dropouts at
25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?
As much RAM as possible ?
A more expensive capture card than a cheap 40 Winfast TV2000XP ?

I assume all the above but I want to pick one option first and see the
results due to financial constaints.

Many thanks,


Richard Brooks.






  #9  
Old February 17th 04, 09:15 AM posted to uk.tech.tv.video.pvr
Simon Slavin
external usenet poster
 
Posts: 457
Default Computer bottlenecks

On 15/02/2004, Richard Brooks wrote in message
:

Which change in a computer setup would give less capture frame dropouts
at 25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?


It's either fast enough or it isn't. If you've ever captured five
minutes without dropouts then it's fast enough.

As much RAM as possible ?


You either have enough or you don't. See above. After a certain
point, it's pointless expanding it.

Though you may want to make sure you're not running badly-written
CPU-hungry programs in the background (e.g. Word) while you're
capturing.



This comes down to how, precisely, the cards work.

Others:

Making sure you have the minimum number of windows open while capturing.
Turning networking off while you're capturing.
Disabling keyboard-switching while you're capturing.

Simon.
--
Using pre-release version of newsreader.
Please tell me if it does weird things.
  #10  
Old February 18th 04, 06:01 PM posted to uk.tech.tv.video.pvr
Richard Brooks
external usenet poster
 
Posts: 4
Default Computer bottlenecks

Simon Slavin wrote:
On 15/02/2004, Richard Brooks wrote in message
:

Which change in a computer setup would give less capture frame
dropouts at 25 fps and at greater than 640 * 480 frame size ?

A hard drive with a high spindle speed ?


It's either fast enough or it isn't. If you've ever captured five
minutes without dropouts then it's fast enough.


I wasn't writing philosophically! In the line at the top I see a "less
capture frame dropouts" so that one would understand from that, that frame
droputs were actually happening.

As with any system one could have a top range computer using a slow spindle
speed drive and have the same basic effect as a lower spec' machine with a
10k spindle speed drive. Also: see subject title.

Previously I had the luxury of having an PAR card that had it's own on-board
EIDE interface and drives so no problem for the motherboard.


As much RAM as possible ?


You either have enough or you don't. See above. After a certain
point, it's pointless expanding it.


Unless dropouts are occuring! See above.

[snipped]


Richard.


 




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