dual capturing

[freebird1963]

I have about 500 video tapes to capture and convert to DVD.
I have both a advc-55 (firewire) and a adstech dvdxpress (usb) each with its own vcr connected.
I was wondering if it might be possible to put a tape into each one and to capture both at the same time.
I would setup the capture files to different hard drives. Or same Hard drive if that might be better.

768 megs ram. 1.36 ghz intel cpu.

THanks
Mark

[RDS1955]

I'm not a PC Guru, but I "believe" capturing can be a CPU intensive ordeal....You see so many posts from a wide variety of folks in here who speak about dropping or losing frames in the process..I could be totally wrong, but IHO I'd only go with one at a time...That'd be the safest route for me anyway...

[edDV]

Best way to find out is to try it and see. DV capture through the ADVC is not very CPU intensive since the DV encode is done in hardware.

I've never heard of a adstech dvdxpress and its CPU or its PCI bridge loading to a HDD. You need to do some basic systems analysis.

I can manage a ATI AIW + IEEE-1394 HDTV TS stream capture at the same time to the same HDD without overloading.

An ADVC + PVR-250 (both hardware encoders) would be no problem.

BeyondTV's Medusa has no problem with 6 PVR-250s capturing at the same time.
http://www.byopvr.com/displayarticle168-flat.html

But, the same machine trying to capture a single stream from a BT 8xx card to Pinnacle Studio encoding MPeg2 would overload and loose frames.

[edDV]

I just ran some tests here:

Pentium 4 2.4 GHz, 1 GB DRAM (no Hyperthreading)
---------------------------------------------------------
CPU idle 3-5%
1080i 20Mbps TS stream capture 8-10% CPU

ATI AIW display (no capture) 12-20% CPU
ATI AIW display + MPeg2 352x480 capture using MMC 27-33% CPU
(above + 1080i 20Mbps TS stream capture 32-36%% CPU)

ATI AIW display + MPeg2 720x480 (high) capture using MMC 55-61% CPU
(above + 1080i 20Mbps TS stream capture 58-65%% CPU)

plus
ATI AIW display + MPeg2 capture using Beyond TV MPeg2 (good) 58-68% CPU
(above + 1080i 20Mbps TS stream capture 58-68%% CPU)

Note that in all cases I'm just capturing the HDTV TS stream not displaying it. Display alone takes 86-100% CPU with VLC player.

Another reference point from my Celeron 2.4 machine (1GB RAM) capturing from Canopus ADVC-100 DV to realtime Mainconcept MPeg2 8/7/4 VBR encode (ULead Video Studio 8 ) uses 77-88% CPU with some 100% buffer flushes (no frames lost).

[reboot]

Dual capturing with my PVR-500 is 3% CPU.
Quad, using both cards, is 4% CPU.
All to the same hard drive.

[edDV]

Dual capturing with my PVR-500 is 3% CPU.
Quad, using both cards, is 4% CPU.
All to the same hard drive.

That would be without display? Or does the PVR-500 process MPeg2 display in hardware too?

[reboot]

Without display.
With display (of one recording at a time), CPU usage is between 19% and 24%, and that includes the PVR software, two web browsers, a demuxer, and 20 processes running.