Ant said:
Hello.
How do I get a new Lenovo notebook/laptop to show its screen and two big
wide screen monitors (DVI) to show up at the same time? Basically three
screens. I can get two of them (laptop/notebook's and a monitor) up
though. Just not all three. 1.5 GB VRAM should be enough. I don't know
if onboard Intel is enough though.
Thank you in advance.
The issue is not the number of connectors on a computer.
The video card has two sides (in the block diagram below).
The display pipelines are on the left, then there's a
"digital crossbar interconnect", then the display outputs
(VGA/DVI/HDMI/DisplayPort/SVideo etc).
On older GPUs, in fact the vast majority, there are only
two display pipelines. If a video card has three connectors
on the faceplate, you can use any two of three connectors.
While in theory, you could "mirror" a display channel to
two connectors, that doesn't seem to happen in practice.
(The crossbar would allow it, the driver writer might not.)
I use this doc, as a reference. This is the "old way".
On this PDF, see page 8. If using Acrobat Reader to
read the doc, be patient. On a slow computer, it
can take up to 20 seconds, for the yellowish image
on page 8 to render.
http://web.archive.org/web/20070302...000_Family_Technology_Overview_Whitepaper.pdf
If you can't get the PDF, you can try the GIF copy I
made here. It's equally annoying in terms of rendering
speed
http://img826.imageshack.us/img826/2990/crossbar.gif
*******
ATI came out with Eyefinity, where the GPU can run as
many as six displays at once. The ATI product line,
varies as to how many of those are connected. Generally,
two channels are DVI/VGA capable, while the others are
DisplayPort. Presumably, there's a technical explanation
for why it works that way. (A description I read, mentions
"clocks" and that the DisplayPort connectors aren't using
a clock signal from the GPU.)
http://en.wikipedia.org/wiki/Eyefinity#Multi-display_technologies
"AMD also introduced AMD Eyefinity Technology (previously
ATI Eyefinity) in this GPU family - the ability to connect
three to six displays to one graphics card. It also supports
grouping of multiple monitors into a single large surface (SLS),
treated by the OS as a single monitor with very high resolutions.
It is promoted as an inexpensive alternative for ultra-high
resolution displays."
This is the crossbar in some of the newer ATI cards.
It's the addition of the pipelines on the left, that
enables more than two.
http://www.pcper.com/images/reviews/783/crossbar.jpg
(From this review
http://www.pcper.com/reviews/Graphi...Card-and-AMD-Eyefinity-Review/AMD-Eyefinity-T
)
When you have the display pipelines, you can run
more monitors with unique output. While it can be
done by using more GPUs, that's not typically
how a laptop is set up. You could search
for a laptop touting Eyefinity, but good
luck finding one.
And I don't know if NVidia bothered doing more
display pipelines or not. I think their products
are still the traditional two display pipelines.
Paul