Hi everybody, Does anyone the advantages of the Spectra8/Winnov Videum 4400 over the Hauppauge Impact VCB?
The hauppauge card is almost 5 times cheaper than the others. Maybe there is something am I missing? Thanks in advance for ur help. Kind regards, Natalia. ----- Original Message ----- From: "Natalia Costas Lago" <nata...@cesga.es> To: "Derek Piper" <dcpi...@indiana.edu> Cc: "ag-tech" <ag-t...@mcs.anl.gov> Sent: Monday, April 25, 2005 4:05 PM Subject: Re: [AG-TECH] Quad Capture card performance > > Thanx a lot Derek!! > > That was enlightening!! > > ----- Original Message ----- > From: "Derek Piper" <dcpi...@indiana.edu> > To: "John Hodrien" <jo...@comp.leeds.ac.uk> > Cc: "ag-tech" <ag-t...@mcs.anl.gov>; "Natalia Costas Lago" > <nata...@cesga.es> > Sent: Monday, April 25, 2005 3:29 PM > Subject: Re: [AG-TECH] Quad Capture card performance > > >> >> Of course if the system you're installing on only supports 32-bit x 33Mhz >> slots (as many do) then you're not going to get a lot of benefit. >> Natalia, what are the hardware specs on the capture machine you're >> upgrading or rebuilding? >> It's important to note too that however many PCI *slots* you have, you >> (normally) only have one PCI *bus*. And the TOTAL bandwidth of that bus >> is 32bit x 33Mhz = 132MBytes/sec. So however the cards are arranged >> (singly or quad) you're going to run into that same bandwidth limitation. >> Of course the quad capture card might be slightly more efficient due to >> it being the only card on the bus and thus eliminating bus contention >> between the capture cards. >> To reiterate the math here? >> >> 33000000 x 32 = 1056000000 bits/sec PCI max >> >> = 132000000 bytes/sec PCI max >> >> 1 frame (24 bit color) = (768 x 576 x 24 / 8 ) = 1327104 bytes >> >> 25 fps = 33177600 bytes/sec >> >> x 2 captures = 66355200 bytes/sec >> >> x 3 captures = 99532800 bytes/sec >> >> x 4 captures = 132710400 bytes/sec >> >> Derek >> >> John Hodrien wrote: >>> On Mon, 25 Apr 2005, Natalia Costas Lago wrote: >>> >>>> >>>> We are about to purchase a Spectra8 capture card or Winnov Videum 4400. >>>> It's >>>> a very good point not to have to use 4 PCI buses, that's what I like >>>> most of >>>> both cards, however I am concerned to performance issues, I mean, a PCI >>>> bus >>>> allows 132 Mbps more or less, and the Spectra8 delivers 4 videostreams >>>> at >>>> 30fps 768x576 (it can be less, that's the worst case) (similar values >>>> for >>>> the Videum 4400 card). So, it seems to me that the PCI bus cannot >>>> transmit >>>> so much information, that means, does it drop frames? Maybe I cant get >>>> the >>>> highest resolution at 30fps (25fps for the Winnov card)?. >>> >>> >>> It won't be 30fps at 768x576 will it? That's PAL resolution at NTSC >>> frame >>> rates. If you drop that to 25fps, the back of my envelope looks like >>> you'd >>> indeed be rather close to 32 bit PCI limits. The 4400 supports 64bit >>> PCI, >>> thus solving that problem. >>> >>> jh >>> >> >> -- >> Derek Piper - dcpi...@indiana.edu - (812) 856 0111 >> IRI 323, School of Informatics >> Indiana University, Bloomington, Indiana >> > >
