[extremepc]

Hi,

I have just bought an Intel G45 based motherboard and intend to use the on board video once Linux support has matured sufficiently. In the meantime I'm interested in purchasing avideo card which is capable of 720p under XBMC reliably.

Can anyone recommend the lowest end video card which can do this? PCI-E of course. The CPU on the system will not be a bottleneck as it's an E8400.

Thanks.

I'm running XBMC and playing 720p/1080p videos silky smooth on an ASUS M2N-MX SE Plus with an AMD AM2 Athlon 64x2 Dual Core 5000+, the onboard video is an NVidia 6100.

[michal]

Just put an order in for the 7300 when I read this about the motherboard I'm using:

"While the PCIe x16 is physically a PCIe x16 slot, you'll only get PCIe x4 speeds out of it."

Should this be causing me concern? Or is 4x plenty for 720p 60fps video via OpenGL2?

[xgrep]

4x is plenty. Even at the 1.1 spec, pcie 4x should be able to push 1Gbyte/sec, where you biggest 1080p movie will only ask for a max of 40mbit/sec.

Your only concern would be if your 16x card is able to handle 4x. Which some quick searches online looks like it should be fine.

[michal]

Thanks for that info.. Are you sure thought it's only 40mbit/sec?

A quick search reveals that it's a lot more than that:

"Uncompressed 720p60 8 bit 4:2:2- 1280x720 - 105.5 MB/sec" - see http://www.hdforindies.com/2004/08/hd-di...te-storage

That's MB, not mbit. Still, should be plenty.

[michal]

So far it's been a terrible experience.

I've installed the 7300 but the LCD keeps losing the signal. It seems like every 20 seconds or less the screen just blanks. Even if I'm in the bios.

Also, installing Ubuntu 8.04 and 8.10 is impossible in either standard or safe graphics modes.

The onboard Intel video is more compatible than this Nvidia

I haven't been able to figure out what to google for to find similar problems (and hopefully solutions) yet. Any ideas?

[althekiller]

Ubuntu forums would be a good place to start.

These are the kinds of things you need to be prepared for when you go into something with the line drawn at the bottom...

[xgrep]

Blu-ray movies have a maximum data transfer rate of 54 Mbit/s, a maximum AV bitrate of 48 Mbit/s (for both audio and video data), and a maximum video bitrate of 40 Mbit/s.

http://en.wikipedia.org/wiki/Blu-ray_Disc

Not to say you can't have a movie try to push more, I'm just referring to where most HD movies come from.

As for your video issue... first pass would be to check cables, power, plugged in fully, all the basics, etc... If all is still fine, and it's doing it in the bios then it sounds like a hardware issue. Call the place you bought it from.

[althekiller]

I think you guys are talking about two completely different bitrates. xgrep is on about the encoding bitrate, which is irrelevant in this case. michal is talking about the display bitrate (res * depth * framerate) which is what the hardware would have to contend with transferring decoded frames from system RAM to the GPU.

[michal]

I'm not sure what "something with the line drawn at the bottom" is (bleeding edge?) but I think it's broader than Ubuntu.

The problem occurs even in the bios which points at hardware problems or incompatibilities between the motherboard (or some part of it) and the video card. I don't think I can be the only one who has had this problem ut I also doubt there are many people with a G45 based motherboard with onboard video using a PCI-E card

I wonder if this has something to do with voltages. Might try checking out the Nvidia forums too. If anyone gets any ideas or comes across some info I would appreciate a pointer. Thanks.

[michal]

I find this hard to believe, but is it possible that the problem is that my PSU is only 380W?

[michal]

I might install windows and see if i can monitor all the voltages or maybe get some errors. Linux seems completely unaware of the blanking. Maybe Windows is more fragile and I can get an error :/

[BLKMGK]

I'm not sure what "something with the line drawn at the bottom" is (bleeding edge?) but I think it's broader than Ubuntu.<snip>

What he's trying to say is that when you try to do something at the absolute cheapest rockbottom price point you can expect to get what you pay for - problems. Why not just pickup a fanless 8500 NVIDIA like I'm running? Known good, no fan, and it doesn't cost a mint - especially when you consider the headaches you may encounter trying to bump bottom with older stuff. Now, if the issue is the P/S or something else an 8x won't help but if you were already trying to use one and saw this you would sure as heck know the card SHOULD work....

[michal]

Well there are no low-profile fanless 8500's anywhere in this country (Australia) as far as I can tell (or 8400's, 8600's for that matter). I intent to move to a low-profile case so that's important until the G45 IGP is better supported.

Also, I wouldn't say this was the cheapest setup. Only the Nvidia card is low end and that's mainly because of the low-profile/fanless requirement. I might add that it has absolutely no problem with playing back the content (even 1080p) but it seems as if it was losing power (or something for a few seconds every once in a while. Sometimes often and sometimes not. And it does so regardless of where you are, including in the BIOS, or while playing back video (though this does not interrupt the video).

It's hard to diagnose. Perhaps there is a fault with DPMS (or whatever it is that tells the monitor to go to sleep).

[michal]

My suspicion has shifted completely to the output of the 7300. I think that must be where the problem is. That's the only way it can make sense :/

Testing it in another system or another PCI-E card in this system would be quite difficult. I'll try to look for a DSUB cable to see if the problem only occurs via DVI.

[michal]

OK. The problem disappears via the DSUB connector. A weird jumping of the screen by one or two pixels to the side and back also disappears via the DSUB.

The problem must be a faulty DVI output on the card.