[wplug] video card power consumption -- performance comparison ...

[Patrick Wagstrom]

Bryan J. Smith wrote:
> The G70 series (e.g., GeForce 7050 chipset integrated GPU) are supposed
> to have far better video off-load than the NV40 (e.g., GeForce 61x0
> chipset integrated GPU), although the G80 even better than G70 (although
> I haven't seen the G80 chipset integrated GPU yet -- they typically come
> out much later after the cards).  MPlayer and other open source projects
> often take advantage of these nVidia accelerations, although standard Xv
> and other video, overlay, etc... features "just work" because nVidia is
> really good at supporting open standards (even if their drivers are not
> open source -- that's always been their hallmark, including AIGLX almost
> "off-the-bat" in a beta driver).

Actually, offloading video work to the cards is accomplished using XvMC, 
something that Intel, NVidia, and Via Unichrome chips support.  Of the 
three, only Via supports offloading anything other than MPEG2 (they 
support MPEG4 in addition) despite the fact that the drivers for windows 
for all three cards also accelerate H.264.

There's been some work in MythTV in offloading transcoding work to the 
GPU, so the GPU does the scaling and re-encoding of the video frames. 
This works best with Nvidia drivers, but it's nascent at best and not to 
the point that I'd trust it yet.

ATI is a non-starter for these because their drivers don't support large 
video textures (anything > 1024x1024 is a no go, which means no HDTV 
support in Linux).

Also, for what it's worth, NVidia was the 3rd player to get AIGLX driver 
support.  First was Intel because RH modified the driver themselves, 
then the open soure ATI, then about a month later came Nvidia.  I'll 
also point out that the open source ATI driver supports 3d while the 
open source Nvidia driver not (nouveau is getting there, but not quite 
yet).  Of course, I'm a pragmatist here, and realize that most likely 
I'll be using nvidia's closed driver.

> I don't think people realize how much is "missing" in the Intel open
> source drivers -- both the utter lack of a kernel driver, plus the lack
> of features in the user-space X11 driver -- which affect even 2D,
> including video playback, overlay, etc...

You really should check out the newest Intel drivers.  Support for XvMC, 
3d acceleration good enough for AIGLX, and full xrandr 1.2 support -- 
which means on the fly output detection.  I saw keithp demo this last 
year at the Boston GNOME Summit and it was hella cool.  Just plug in a 
new monitor and X recognizes it, configures it, and extends your desktop 
without having to restart your session.  Heck, with it, you don't need 
that ugly xorg.conf file anymore.  Also, afaik, the Intel cards are the 
only ones that support true hardware rotation.  It's nice being able to 
rotate a 1680x1050 display to portrait mode.

> Anyhoo, my point, your current nVidia GeForce 6600LE _is_ overkill.
> Back in 2006, I used to maintain tables on the 6000/7000 series ... (I
> stopped because of BlogSpot's stupid formatting issues):  
> http://thebs413.blogspot.com/2006/02/geforce-6-and-7-series-variants-nuts.html

Yup, it is overkill.  But my current card 6600 is fanless and didn't 
cost much, which made it a good candidate for my MythTV box.  The fact 
of the matter is that GeForce 4mx will run high-def for MythTV just 
fine.  However, just try finding one of those in a PCI-Express interface.

> > Again, I haven't seen any "chipset integrated" GPUs yet from the G80
> series, not even for notebooks.  But I haven't kept up either.

The integrated 8000 series GPUs aren't out yet.  In fact, there still 
are very few board with the 7050 integrated.  Anyway, performance is not 
an issue, but power consumption and heat are the issue.  There used to 
be a fanless 5000 series PCI-E nvidia card that some folks had, 
unfortunately, I can't find it anymore.  It seems like that may be 
ideal.  However, there is always the lure of Quake 4 in the living room.

Anyway, while that's a good regurgitation on the current state of video 
cards and drivers, it doesn't get me any closer to getting information 
on power consumption.

--Patrick