LCD: what's going on at 30in 2560?


R

rjn

My next monitor would like to be a 30in 2560x1600 LCD,
but as I survey the market, everything out there seems
to have surprises [some nasty] for anyone approaching
them with expectations set by smaller displays.

Here, for example, is one very unhappy customer:
<http://www.theinquirer.net/gb/inquirer/news/2007/10/26/charlie-rants-
dell>

What are the issues?
1. DVI-D only - no VGA or analog TV
2. Dual link DVI only
3. No scaler, even for digital
4. No HMDI either
5. No on-board setup controls


1. DVI-D (Digital) only

You have to have a DVI card, and a dual-link DVI card
at that. You cannot use any of these monitors with the
analog "DVI-A" signal in a DVI connector. You cannot
use them with a VGA/Dsub15 connection.

No, you can't use this with that old S-VGA PC.

This also means no TV. No YPbPr, no Y-C, no composite
video, no RF.

And even though LCD2560 is digital-only, there is also
no HDMI. See point 4.


2. Dual Link only

This is a pretty much an unavoidable consequence of the
original DVI spec's being somewhat unambitious. DVI was
originally designed to hit about 1600x1200 on a single
link, and only gets to 1920x1200 by CVT trickery. It could
go higher at reduced frame rates, or by using compression,
but no one seems to be interested in going there.

So you need a dual-link card. Note: that's dual LINK and
not dual-PORT (unless the single-link dual-port card
includes a cable and controls to shotgun two single-link
ports into a single dual link DVI-D connector, and I
suspect none do).

Most current cards are dual-link, the Matrox PCIe's being
a notable exception. If you want to run a 30in LCD2560 on
a Matrox card, you are pretty well out of luck, unless you
have a PCI-64 or PCI-X slot and a generous checkbook.

Also, as The Inq pointed out, KVM switching of dual-link
DVD-D is not a solved problem. If you share the LCD between
two systems, make sure the monitor itself has multiple DVI
inputs (some do - some, like the Dell, have only one).

Question 1: How do these monitors behave on single-link?

Many, perhaps all, dual-link DVI-D cards power up with
only one of the links active. When hit with a 640x480
boot/BIOS raster, or an 800x600 o.s. setup raster, what
do the LCD2560's display? My guess is a 1:1 raster
postage stamp in the upper left corner.


3. No Scaler

These monitors want to run at 2560x1600, period.
Some may 2x scale 1280x800 (half res), but anything else
will either be a postage stamp in the corner, or black.

Connect your upscaling DVD player or BR/HD-DVD with DVI
out and you may get black or a postage stamp, but you
will not get an image scaled to full screen.

Question 2: Why is this?

My guess is that the high bit rate is expensive to re-sample
and upscale. Given the recent price collapse in 1920 LCDs,
it's apparent that cheap 1920 scalers exist, but 1920 may
be their top end capability.


4. No HDMI

Got a DVI-HDMI adaptor cable?
It won't work either, and not just because the lack of a
scaler means the LCD2560 can't handle HDMI rasters.

If my suspicion about the bit rate is true, then it's
probably also too expensive to handle HDCP at 2560.


5. No On-Board Setup Controls

The current crop of LCD2560s apparently have only rudimentary
front panel controls, and no on-screen controls. Need to set
backlight level, black point, white point, gamma and color temp?
You could be in trouble.

They may rely on host applet/driver configuration software that:
a. May not be available for your OS.
b. May only tweak the graphics card, and not actually set
something persistent in the LCD. If so, you can't setup on
Windows and then hookup the LCD up to Linux with those
settings intact.

Question 3: Why is this?

With no need to handle analog, or re-scale digital, it's
probably too expensive to implement an on-board processor
and 2560 content generator just for monitor setup.


If this is the state of the art, we then move to:

Question 4: Is any of this likely to change anytime soon?

The dual-link requirement I do not expect to see change,
but will future LCD2560 monitors ever get: (in the order of
my priorities): local setup, scaling, analog or HDCP/HDMI?

Since what I'm mainly interested in is getting to 1600 vertical
at no smaller than 100 dpi, another alternative is multi-head.
I already use dual 1600x1200 (landscape) on one system, and
will shortly try out dual-portrait.

And then, of course, there's the matter of the price of LCD2560.
At today's prices, it's already cheaper to get 2560 pixels
wide, and beyond, using dual- or triple-head. Moving from
3-strip Cinerama to 70mm Panavision could be an expensive
preference.
 
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B

Bob Myers

rjn said:
What are the issues?
1. DVI-D only - no VGA or analog TV
2. Dual link DVI only
3. No scaler, even for digital
4. No HMDI either
5. No on-board setup controls

These all come from the same root cause - until VERY recently,
there have been no scaler/controller ICs capable of supporting
the video rates required for 2560 x 1600 @ 60 Hz. Such
things are just coming to the market now (meaning that the
scaler makers have just started producing them, not that they're
actually in monitors just yet).

HDMI, except for the latest version (HDMI 1.3) also cannot
run fast enough to support this format; ditto single-link DVI.
In the absence of a scaler, it therefore makes little sense to
provide any of these, including VGA/analog TV.

Bob M.
 
R

rjn

Bob Myers said:
These all come from the same root cause - until VERY recently,
there have been no scaler/controller ICs capable of supporting
the video rates required for 2560 x 1600 @ 60 Hz. Such
things are just coming to the market now (meaning that the
scaler makers have just started producing them, not that they're
actually in monitors just yet).

Is "yet" here now?

"Dell's next-gen 30-incher sports Displayport and HDMI"
<http://snipurl.com/1tkrh>
"The video processing chip in the monitor will enable decent
resolution scalability, so you will be able to use 2560x1600,
1920x1200, 1920x1080, 1680x1050 and all other often used
resolutions."

And is DisplayPort the next EVC?
It doesn't look terribly appealing.
 
B

Bob Myers

rjn said:
Is "yet" here now?

Well, Bob, I'm going to have to invoke my usual rule
about not commenting on specific makers or products
here - but I think you can draw your own conclusions.

And is DisplayPort the next EVC?
It doesn't look terribly appealing.

Gee, you're never gonna let me forget that EVC thing, are
you? :)

No, DisplayPort is definitely not the next EVC.
Numerous big-name players have already announced
coming support for the interface (Google should help
here, or just look to see who's been active in the VESA
DisplayPort effort, as well as who's in the group which originally
proposed the interface to VESA). I (and others) are expecting
DisplayPort to be THE digital interface standard for future
PCs. Clearly, it is going to take some time to make an
orderly transition from DVI (and especially VGA), but
DP has some very clear advantages that are offered by
no other digital interface. Such things as a 10.8 Gbps
capacity on the standard connector (better than what you
get on a dual-link DVI), and with a significant upgrade to
that rate planned in the future (without breaking backward
compatibility), and (in a first for ANY standard digital
interface) a packetized communications protocol (which
will enable such things as multiple displays per single
physical output, etc.). DisplayPort is also based on the
industry-standard PCI-Express electricals, and doesn't
suffer from the licensing & royalty issues that have plagued
other attempts at bringing a digital interface standard to
the PC industry.

Bob M.
 
R

rjn

Bob Myers said:
here - but I think you can draw your own conclusions.

I was surprised to see the 3007WFP-HC hit the press.
Your comment about the state of the scaler/controller
art led me to expect nothing until 2008.
Gee, you're never gonna let me forget that EVC thing, are
you? :)

I never considered it to be your fault (until now, anyway :).
And hey, the micro-cross has served DVI well.
In other might-as-well-be-proprietary video port news,
where I'm working now, we're just retiring the last of
the 13W3 monitors this year.
 
N

Not Gimpy Anymore

rjn said:
Is "yet" here now?

"Dell's next-gen 30-incher sports Displayport and HDMI"
<http://snipurl.com/1tkrh>
"The video processing chip in the monitor will enable decent
resolution scalability, so you will be able to use 2560x1600,
1920x1200, 1920x1080, 1680x1050 and all other often used
resolutions."

Well, that is a bit more capability than the published specs for
an HP LP3065, but still pretty much a "closed system"..... in the
sense of requiring a DisplayPort connection as well as limited
support of the smaller pixel formats.
And is DisplayPort the next EVC?
It doesn't look terribly appealing.

Regardless of apparant appeal, or lack thereof, DisplayPort
(DP) does seem to be on its way to wide industry acceptance,
as Bob Myers also indicated.
VESA is sponsoring a DP PlugTest next month, and the list
of attendees is impressive (to me, at least). However, it is not
allowed to attend as an observer - to attend, one must have
a DP product, and must test it. Actual test results will be
confidential, for reasons that seem pretty obvious.
VESA also has published quite a bit of information for DP
on their web page www.vesa.org However, it is worthy of
note that even VESA does mention it is suitabe for "closed
system aplications".
Whether there will ever be a full scale replacement for the
common VGA connector is still most likely to be determined
by market pressures, and not technical excellence....(sad to
say, but generally proven true over the years).
FWIW, there seem to be two emerging philosophies for DP,
each at "opposite ends of the spectrum". Some plan to position
it on "high end" systems, and others plan the opposite, to position
it on "economy systems".... Not sure which is more likely to
end up succeeding - maybe both.....

NGA
 
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R

rjn

Not Gimpy Anymore said:
Well, that is a bit more capability than the published specs for
an HP LP3065, ...

Well, the LP3065 is still a first-gen 2560LCD, as were the
previous Dells. The hp did at least have 3 sets of DVI inputs,
but it otherwise apparently shared the limitations resulting
from no scaler/processor.

Presumably hp is working on a replacement for the LP3065,
under the guidance of Professor Myers. Apple can't be far
behind either.

The interesting thing to watch in the 2nd gen will be for any
evolution of the backlights and increases in bit depth. Alas,
I'm guessing that they'll be just "enhanced" CCFL BLUs,
and still 8 bit panels.

For those who can live with the limitations of the 1st gen,
don't be surprised if some real fire sale prices appear soon.
 
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M

Mike Ruskai

Well, the LP3065 is still a first-gen 2560LCD, as were the
previous Dells. The hp did at least have 3 sets of DVI inputs,
but it otherwise apparently shared the limitations resulting
from no scaler/processor.

Not much of a limitation, seeing as any card with a dual-link DVI port
is going to be smart enough to scale other resolutions, based on the
reported display capabilities, without any driver.

My LP3065 isn't blank on bootup - the graphics card scales the
text-mode window to fill the screen, and there's no performance hit
with the scaling (it's an extremely simple operation, after all).
Presumably hp is working on a replacement for the LP3065,
under the guidance of Professor Myers. Apple can't be far
behind either.

Apple's current offering claims to support other resolutions, so maybe
HP is the one that's behind.
For those who can live with the limitations of the 1st gen,
don't be surprised if some real fire sale prices appear soon.

They'll still be quite expensive, I'm sure. I'd probably be extremely
tempted to get a second one if they dipped below $1K, though it'd
require a new desk.
 

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