"Paul" wrote in message
...
W wrote:
"Paul" wrote in message
...
W wrote:
I have an older XP computer in a living room on which I installed an
nVidia
GEForce 8800 Ultra. The card performs well, but to my disbelief with
the
monitor turned off and the computer doing nothing but displaying an
inactive
Windows desktop, the nVidia card is consuming about 160 watts of
energy
continuously. Since the system is only used to run a few virtual
machines
about 99% of the time, that is a lot of wasted energy. I want a
card
that can stop burning watts when it is in a low use mode.
Does anyone make a top tier video card that can power itself to a
minimum
power utilization mode when the card is not being used heavily? I
read
somewhere that some newer version of AMD Eyefinity could get power
utilization in an unused mode down under 20 watts. What are details
on
that?
This is true of newer cards from either company.
The ratio of 3D_max to Idle is improving. Your card could be 70W
at idle (measured at the card), and newer cards have actually
improved on that.
Xbitlabs.com used to do per-rail power measurement, using
a specially modified motherboard, but they've stopped doing
that, and so we no longer have those measurements available
for newer cards. All they do now is system power measurements,
which are useless for determining the exact 3D_max to Idle ratio.
(If they had a "system power with no video present" measurement,
then, their measurements would have some value.)
All I can tell you, is a newer card will *likely* be lower
at idle. The 8800 is still back in the "bad" days.
This is another one of those sites that only does system power.
HD 7970 "system idle" 113W, "system 3D Max" 391W. So the idle
is better there. Your card is around 70W idle, 131W max, which
means ratio-wise, it doesn't do that well at idle.
http://www.anandtech.com/show/5261/a...7970-review/27
There was an era, when silicon gates were relatively leaky.
Intel Prescott was an example of that, where 25% of DC power
was just wasted as heat, and did nothing for you. While chips
still leak, more development work has gone into making
structures for gates, which don't leak quite as bad as that.
(The geometry of the gates shrunk, and the gates and silicon
structures had to be redesigned to prevent leakage from them
rising worse than the Prescott era.) The other improvement
comes from clock gating - where desktop cards are now closer
to how mobile graphics work, in terms of clock gating.
There's a good chance, that no matter what card you buy,
it'll do better than your 70W idle 8800 family card.
It's not clear what the data you report means if it is a measurement of
total power used by the system. You would have to subtract out the
system
power use when no video card is installed to get any kind of proxy for
power
used by the video card alone?
This article:
http://us.digitalversus.com/graphics...4621/test.html
in the section named "Power Use" is suggesting that the ATI 7850 can go
into
an idle mode that uses 3 watts. Effectively the card turns itself off:
"Better still, the excellent ZeroCore Power feature gives a 16%
reduction in
energy consumption at idle and allows you to turn the card's fan off.
For
this, the computer has to be configured so that it switches the screen
off
after a given period of time. As soon as the screen goes on standby, the
card is almost entirely switched off and only consumes 3 watts of power,
bringing the overall consumption of our test computer down to 74 watts."
On my system, the nVidia 8800 Ultra is consuming 160 watts *just for the
power card* and when the system is in idle state. 3 watts versus 160
watts is a huge difference?
The Xbitlabs numbers for an 8800 non-Ultra were 70W idle and 131W busy.
In these kinds of articles, as far as I know, the "Idle" power is with
desktop still visible and the user has stopped pushing the mouse around.
These are not system power numbers, these are video card only, measured
with
current shunt in 3.3V_slot, 12V_slot, 12V_PCIE#1 and 12V_PCIE#2 (if they
exist).
Xbitlabs have stopped doing it this way, because it looks like they got
another motherboard, and aren't interested in fitting the shunts.
http://www.xbitlabs.com/articles/gra...0_3.html#sect0
The idle power of the card varies with the card's processing power in
those
charts. The HD 5970 for example, is still 44.4W for the card. A low
end card like the HD 5450 is 3.2W idle.
If I believe the AMD web site, the RADEON ZeroCore power technology will
put the video card into a sleep state that uses less than 4 watts while the
system is running with the screen off. Good or bad, my computer will act
as a server and the system will not sleep. But the screen will be resting
99% of the time and during that rest time I want to minimize the power draw.
What is the most powerful AMD video card that fully implements the ZeroCore
technology today?
Turning off the screen is good for servers, but for a desktop
isn't the best choice. Mainly because a desktop is more
interactive, and if you aren't using it, chances are you've
used S3 sleep or S4 Hibernate.
It is not that unusual for a computer to act like a server and run virtual
machines in the background. In my case those run a home active directory
and some other administrative servers.
--
W