[wplug] video card power consumption

Bryan J. Smith b.j.smith at ieee.org
Mon Sep 10 08:15:50 EDT 2007


On Sun, 2007-09-09 at 22:05 -0400, Patrick Wagstrom wrote:
> Does anyone know of a site that provides a good comparison of the power 
> consumption of modern video cards?

Anand, Tom's, Xbit, etc... regularly check total system power
consumption with various video cards, although most of them only focus
on higher-end cards.  I guess it's a bit hard to measure video card
power consumption because there are multiple power rails coming in on
the slot (even if the additional 6-pin PCIe connector is easy to measure
-- that's only for when the PCIe slot can't provide the 150W+ required).

> Overall performance isn't critical for me as it's just running MythTV
> over a DVI->HDMI cable.  Hopefully someone knows of a good site where
> I can look at some of the tradeoffs of the cards.
> If need be, I'm not opposed to upgrading motherboards to something with 
> integrated video either.

Well that definitely makes things easier.

First off, I've always had a hell of a time with integrated Intel cards
and non-PC video output.  Intel still keeps a bit of their GPU's secret
for IP reasons.  E.g., Intel doesn't provide a kernel driver for Linux
(direct memory execution and other optimizations), which is why their
performance on Linux sucks compared to Windows (although ATI and nVidia
do release a kernel driver in their proprietary drivers, because some of
the IP is Intel's ;).  But I have no idea why Intel doesn't release some
of the output specifications and timing, which have to be reverse
engineered (can't remember the project).  Someone said this has changed,
but the last time I checked, it was still a "reverse engineering"
utility separate from the driver (again, can't remember the project).
All I know is that I was estatic when I found the project because my
i855GM and i915GM notebooks were a PITA when I connected them to
projectors (and I wasn't alone).

Secondly, AMD is now promising to release specifications on their ATI
cards output, which is about time.  But it hasn't been done yet.  The
latest proprietary drivers have massively improved both performance and
support in Linux.  But I don't know about their output support.  So ...

Third, I'm a nVidia fan, largely because they've been over 90% Linux
in-house since '99, and that's why they started making drivers
(especially back in the late '90s when companies were considering
porting their CAM/EDA apps to NT/DirectX, and nVidia gave them a way to
keep them on UNIX/OpenGL, by going Linux with nVidia).  nVidia first
released _all_ source code for XFree86 3.3 in '99, and was summarily
sent "cease'n desist" orders from lawyers at Intel, Microsoft, SGI,
etc...  Since then, they've shipped their "unified driver" object files
that runs on all OSes, and then wrapper code to run for the kernel,
user-space X11, etc... (which makes the GPL interesting since the driver
wasn't designed for Linux -- Linus is an interesting read on this).
Anyhoo, nVidia has always taken non-PC output very seriously and it is
very well supported in the proprietary driver.  Their used to be good
support for non-PC output even for the MIT 2D X11 driver with an added
utility, but I don't think that is the case anymore with the 6000+
because more and more has gone in the GPU.  I honestly don't know
because I just use the proprietary driver.

With that all said ...

nVidia's latest "lower-end" products in the G80/8000 series is supposed
to cut power significantly over the G70/7000 and NV40/6000 series.
E.g., they regularly highly the power savings of the Go 8400 and Go 8600
in notebooks over their equivalent Go 7000 series.  But they haven't
released a "lower power" version for the desktop yet AFAIK, or maybe
there is a GeForce 8400 now.  In any case, there are GeForce 7050
chipset integrated, as well as GeForce 6150, 6100 and 6150LE (basically
worse than 6100) chipset integrated video.  The great thing is that they
_commonly_ come in sub-$50 MicroATX mainboards, great for small
form-factor.  The other nice thing is that the MCP44, MCP51 and MCP61
peripherals have _very_well_supported_ and 100% GPL drivers for ATA,
NIC, audio, etc... on kernel 2.6 -- better than Intel IMHO (especially
ATA at times, Intel seems to keep 'screwing the pooch' with newer ICH8
and ICH9 logic changes that prevent the existing support from working).

BTW, I have _no_idea_ about the AMD (fka ATI) G690 chipset, but most
people are having peripheral support issues -- e.g., ATA, NIC, etc...
It looks tempting given the price with HDMI output options, but I've
seen nVidia GeForce 7059 chipset integrated options with HDMI too.

Lastly, just so I don't ignore them, Matrox _does_ offer cards as well.
Matrox, like Intel, does not provide a kernel driver AFAIK.  This only
affects performance.  Matrox's X11 drivers are still proprietary, but
they are easier to load (again, because of the lack of a kernel driver).
But I have never used their non-PC output either.

> So, anyone know where I can find something like tomshardware.com VGA 
> charts that shows power consumption?


-- 
Bryan J. Smith         Professional, Technical Annoyance
mailto:b.j.smith at ieee.org   http://thebs413.blogspot.com
--------------------------------------------------------
        Fission Power:  An Inconvenient Solution




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