PCI vs USB

Jarobata · 2007-09-10, 04:40 PM

Does one tend to render a better quality image than the other? I ask because I'm getting interference with a PCI card and I imagine if I used USB I could eliminate many possible sources of interference. If USB is just as good as PCI, is there a USB setup that's considered the best?

K.S. · 2007-09-10, 05:08 PM

i assume you talk about a capture device... from my own past experiences it does not really matter if PCI or USB regarding image quality. i had a hauppauge WinTV-PVR-350 (analog PCI) and have got a very good image quality. about your interference: try to find the source. what kind of signal do you receive? analog / digital (DVB-T/S etc..)? try to find out if the signal you get is OK. i.e.: if you are analog, is the image the same quality if you use the same cable directly to your TV? does the image improve if you use other/shielded cables? i hope you get the image, try to find out where the interferences come from (it's unlikely that they appear in the PCI card, that should be shielded very good or you would have other problems ;-)

Jarobata · 2007-09-10, 07:01 PM

K.S. Wrote:i assume you talk about a capture device... from my own past experiences it does not really matter if PCI or USB regarding image quality. i had a hauppauge WinTV-PVR-350 (analog PCI) and have got a very good image quality. about your interference: try to find the source. what kind of signal do you receive? analog / digital (DVB-T/S etc..)? try to find out if the signal you get is OK. i.e.: if you are analog, is the image the same quality if you use the same cable directly to your TV? does the image improve if you use other/shielded cables? i hope you get the image, try to find out where the interferences come from (it's unlikely that they appear in the PCI card, that should be shielded very good or you would have other problems ;-)

I'm pretty positive it's interference from within the case, probably from the power supply. It's an analogue signal. Other TV's run off the same wire but have no interference which leads me to believe it's from within the case. I also have quad shielded cable going into the PC.

stustunz · 2007-09-10, 07:26 PM

could be just a faulty card if it is in the case otherwise everybody would be getting it
can you move the card to another slot
can you take a screen shot and post it of the interference its easier sometimes so we can tell you what may be causing it?
almost put money on it that its not in the case though i have pci cards and if there is interference its always the signal or cable.
Is it a stronge signal the tuner cards need a stonger signal than a tv to get a good picture in my opinion

Jarobata · 2007-09-10, 07:31 PM

stustunz Wrote:could be just a faulty card if it is in the case otherwise everybody would be getting it
can you move the card to another slot
can you take a screen shot and post it of the interference its easier sometimes so we can tell you what may be causing it?
almost put money on it that its not in the case though i have pci cards and if there is interference its always the signal or cable.
Is it a stronge signal the tuner cards need a stonger signal than a tv to get a good picture in my opinion

I posted up a quick clip here:
http://forums.nextpvr.com/showthread.php...=pulsating

The signal is split once, sent through an amplifier, then split once more before it gets to my computer. I've tried running it without the amplifier and with only one split and it looks the same. I even ran the signal straight from the wall into the cable box in the next room and then from the cable box to my computer and I noticed slightly less interference but the problem wasn't fixed all together. Unfortunately I got the pci-e version and I only have one express x1 slot and one express x16 slot available. I have it in the x16 because the x1 is right next to the vid card. I'd like to try putting a pci card in so that it's as far away from psu and vid card etc but I don't have one available to test. If my description is confusing you can check out the board layout here:http://www.asrock.com/mb/overview.asp?Mo...eSATA2&s=n
I have an antec smartpower 2.0 500w psu and I read at least one account where a person took out his smartpower and replaced it with a truepower and he received less interference. It's possible my problem is combination of a poorly shielded psu combined with a possibly poorly shielded tuner card.

stustunz · (This post was last modified: 2007-09-10, 08:08 PM by stustunz.)

ok your still having problems i just looked at the thread
im out of ideas
have you got another power supply you could put in
or you could unbolt the one you have and run it outside the box to test
do you have access to a multimeter you could check to see if any AC is coming through the power
and check the voltages are where they should
have you tried plugging a tv in at the exact same point as the pc

Jarobata · 2007-09-10, 08:43 PM

stustunz Wrote:ok your still having problems i just looked at the thread
im out of ideas
have you got another power supply you could put in
or you could unbolt the one you have and run it outside the box to test
do you have access to a multimeter you could check to see if any AC is coming through the power
and check the voltages are where they should
have you tried plugging a tv in at the exact same point as the pc

I thought about unbolting but I figured i couldn't get it far enough away where It'd make much of a difference. I don't have a multimeter, I will borrow a tv and see if I can see it.

pBS · 2007-09-10, 10:58 PM

also make sure your power cables have all 3 pins and are in a 3 prong outlet..
[for proper grounding]
keep any 'signal' cables away from all power cables, specially ac...
or try running power from another outlet...[extension cord] preferably on another circuit...
motors are the usual cause of interference...fans, compressors, etc...
sometimes it's just a badly filtered mo-board...does it have nice big capacitors?

Jarobata · 2007-09-10, 11:03 PM

pBS Wrote:also make sure your power cables have all 3 pins and are in a 3 prong outlet..
[for proper grounding]
keep any 'signal' cables away from all power cables, specially ac...
or try running power from another outlet...[extension cord] preferably on another circuit...
motors are the usual cause of interference...fans, compressors, etc...
sometimes it's just a badly filtered mo-board...does it have nice big capacitors?

I'm not sure what would be qualified as big, you can see them in the picture if you follow that link i provided to the mobo website. I have tons of fans but I tried disconnecting the case fans and nothing changed. I turned off the GPU fan and nothing changed. I think I unplugged the cpu fan for a second and didn't notice a change.

stustunz · (This post was last modified: 2007-09-11, 12:15 AM by stustunz.)

try turning other appliances on and off air con fridge
if you have a power supply from another pc you couldhang that out the side of the box just to rule power supply out
the earthing pBS is talking about is pretty important
tip a bucket of water on your earth peg (OUTSIDE THE ONE IN THE GROUND)sorry just wanted to make it clear what one i was talking about
and check the wire connection to it isnt all corroded

i cant see the pulsing coming from inside the box everthing is pretty well grounded together but check all card screws are tight and all connectors are plugged in good