On 4/10/2024 8:02 PM,
crasso@nycap.rr.com wrote:
My niece, on the other coast from me, has come to me with another
computer question. I'm trying to convince her to buy Forte Agent and
come herself.
She is apparently trying to run multiple monitors in either Win10 and
Win11. Also she doesn't want to have them mirror each other, but
display different screens. In Win10 you go System – Display – Multiple Displays. She gives links to the components she's trying to use. I've
never had more than one monitor on my pc and can't advise her. So I'm
coming to you gurus for any useful intel I can pass along. I'm just
going to copy in her two emails on the subject, maybe you can see
what's she's trying to do and pick some nits.
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Now that I know a little more about all the USBs, I did some trial and
error with my USB C connections, and I still don't understand why it
won't do what I want and how to figure out if all these things will
work before I buy them.
ÿ
What I have now: my 2 screens, the mini projector and portable monitor
hooked up to rhe HDMI splitter pllugged into the HDMI slot of my HP
Pavilion.ÿ But that gives me only Mirror screens and I'd like to used
them as extended display.
ÿ
I can get the extended display by connecting to the projector by WiFi
but this slows down my mouse soÿ much it's useless.
ÿ
I can't get the monitor to work using the USB C connection, with or
without the projector connected, and I thought it would.ÿ Nor can I
use the docking station for the displays, although it works fine for
USB and ethernet.
ÿ
Is there any way to get two independent displays?ÿ Any way I can make
use of the two Display Ports?ÿ Looks to me like there's no such thing
as an HDMI to Display Port adaptor, only the other way around.
ÿ
https://a.co/d/3dg7TaE - [Geforce RTX 3060] 2022 HP Pavilion Gaming
Desktop PC, 32GB RAM, 1TB SSD+2TB HDD, Intel i5-10400F, Wired Mouse & Keyboard, Bluetooth, Wi-Fi, USB Type-C, Display Port, HDMI, Windows
11, Mouse Pad
ÿ
https://a.co/d/9fckIvj - Mini Projector, Magcubic HY300 Auto Keystone Correction Portable Projector, 4K/ 200 ANSI Smart Projector with
2.4/5G WiFi, BT 5.0, 130 Inch Screen, 180 Degree Flip, Round Design,
Home Video Projector
ÿ
https://a.co/d/8mzgesH - KYY Portable Monitor Latest 15.6'' FHD 1080P
USB-C HDMI Laptop Monitor w/Smart Cover Bag & Dual Speakers, External
HDR Computer Screen, Travel Gaming Monitor for PC MAC Phone Xbox PS4/5
Switch
ÿ
https://a.co/d/gblheSc - USB C Docking Station Dual Monitor, 11 in 1
Laptop Docking Station USB C Hub Dual HDMI Adapter Dongle with Gigabit Ethernet 2 HDMI VGA 5 USB PD Audio for HP/Dell/Lenovo/Surface/Chromebook/Thinkpad
ÿ
https://a.co/d/3cKSwAt - Amazon Basics HDMI Splitter 1 in 2 Out,
4K@30Hz for Dual Monitors, Mirror Only, Black
ÿ
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Sorry.ÿ Pavilion=Henry=my Win 11 =
https://a.co/d/3dg7TaE - [Geforce RTX 3060] 2022 HP Pavilion Gaming
Desktop PC, 32GB RAM, 1TB SSD+2TB HDD, Intel i5-10400F, Wired Mouse & Keyboard, Bluetooth, Wi-Fi, USB Type-C, Display Port, HDMI, Windows
11, Mouse Pad
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
ÿ
You've never used multiple extended screens?ÿ Oh, they're great fun.ÿ
It makes me feel like a master of industry, or aÿ security guard,
watching multiple live screens while I work on other things, keeping
up references so I don't have to keep switching back and forth on
tabs.ÿ Keeping a live stream of a birdfeeder up all the time.ÿ It's
like having a larger display with multiple windows.
ÿ
I found an old FB post "I'm playing with using my third screen to give
me a multiple feeder watch including Blue Jays and Cardinals I
remember from my childhood and miss now I'm on the West Coast.
And I haven't been able to figure out how to get a clock on my
computer screen big enough for me to read, but I discovered this
Youtube video of a clock running for 12 hours. Start it and set it to
the current time, and it works just like a real clock."
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
There should be a control panel in the tray.
I can plug in my fake monitor, and get the second item to show.
Doing this, I don't have to dig a monitor out of the junk room
and find a table for it.
[Picture]
https://i.postimg.cc/zB0xcQVy/NVidia-Tray-Control-Panel.gif
Because the native resolutions don't match, the Surround option
isn't offering me anything.
The video card can take one head of output, and spread it over three monitors. This is Surround, and should be tear-free from a head-to-head timing perspective.
+--------------------------+
| 5760x1080 | Single head output inside video card
| |
+--------------------------+
[AKA Surround or Eyefinity]
+--------+--------+--------+
| 1920 | 1920 | 1920 | Crossbar spreads that over three monitors
| 1080 | 1080 | 1080 |
+--------+--------+--------+
The largest surround you can do with one card, is generally six monitors, without resorting to tricks (using products that may not be in production
any more).
+--------+--------+--------+
| 1920 | 1920 | 1920 | You arrange your monitors as a 3x2 matrix and
| 1080 | 1080 | 1080 | sit the monitors in front of a "driving throne".
+--------+--------+--------+
+--------+--------+--------+
| 1920 | 1920 | 1920 |
| 1080 | 1080 | 1080 |
+--------+--------+--------+
The crossbar has dimensional limits (for the scan counter),
so a lot of "checking" is required, if working with say
3x4K monitors, deep color, 140 FPS :-) If you're a wacko,
you have to do the research. One of the recent (expensive)
NVidia cards, is actually missing the necessary link speed
to do deep color and 140 FPS at the same time, which is
why doing your research is still important.
The speed of wiring between FPGAs, has achieved speeds such
as 56Gbit/sec or 112Gbit/sec. That's a means of making arrays
of FPGAs (chips which are $1000 each) and joining their functions.
When you try to do an HDMI cable and achieve similar results,
the loss budget does not allow the cables to be very long.
The launch amplitude of the signal, it's going to be difficult
to make that 1 volt tall at speeds like that, and you need
the height to get the "reach". And if you can't have cables
with a decent length, it's hard to arrange your "driving throne".
The Wikipedia articles on HDMI and DisplayPort, are essential reading
before doing a wacko config. Just so you can ask the right questions
at your computer shop. The staff there aren't going to know either,
but you may get lucky.
*******
Just because you have USB-C, does not mean you have USB4 or
Thunderbolt or Alt-Mode.
https://www.cablematters.com/Blog/USB-C/what-is-usb4
"USB4 uses DisplayPort Alt mode to transmit video to an external display,
and can even be used to daisy chain multiple external displays together.
Introduced with the USB-C connector in earlier generations of USB technology,
USB4 leverages DisplayPort Alt mode in much the same way, although to an
advanced standard. The original USB4 specification supported DisplayPort 1.4,
but the newer USB4 80Gbps standard unlocks the option of DisplayPort 2.1 <=== Exists ???
support, giving it the ability to transmit 4K video at up to 240Hz,
or even handle a single 10K display at up to 60Hz."
This stuff is mostly Sparkle Ponies, and meant to sell "Intel Shit".
On a desktop, you start with a "Thunderbolt Ready" motherboard. What makes it Thunderbold ready, is it has a low-speed "administrator cable", which is cheap logic to slap on the motherboard and is a "zero investment" on their part. Then, you buy a Thunderbolt card for $100-$200 or so, and run two DP cables from your high-end video card to the Thunderbolt card. The video signals
are then carried on the two USB-C connectors on the Thunderbolt card.
https://kmpic.asus.com/images/2020/06/17/ac66317c-db02-4d09-aced-8268c078dd81.png
https://www.asus.com/support/faq/1043485/
You can see this Pyrrhic victory, costs you money, a card slot you
can't afford to lose, some cables, and all so a stinking video signal
comes out on a USB-C. (That's if the monitor can decode it.)
Now, on a laptop, perhaps there is a Thunderbolt chip on the laptop motherboard,
and a DP is already looped through there. The TB chip of course, is going to burn power and waste battery life, but you're a rich cat and who cares
if the laptop to do this costs $3000.
If you bought all sorts of dinky stuff like this, um... good luck.
Gelsinger (tech chief at Intel) is laughing his ass off.
*******
The cheapest HDMI splitter is a passive. It takes a differential R+, R-,
G+, G-, B+, B- and runs R+,G+,B+ to one monitor and R-,G-,B- and
references them to a "static" reference signal. This represents a
lower amplitude HDMI signal, and the two outputs (of course) are
Mirrors.
The other kind of HDMI splitter, amplifies the diff signals and
buffers them, for true/original amplitude outputs. No compromises.
That is an active HDMI splitter. Some of the Chinese 1920 ones
were HDCP strippers, and not only did they split the signal,
they removed the HDCP so that it was more practical to make
the two outputs. Otherwise, whatever protocols run there, may not
be able to configure two monitors at the same time, to do the same
thing. It all depends on the crypto, as to whether two monitors
could support HDCP and Mirror Mode. If you tried to split 4K signals
passive, I have my doubts that would work. Maybe one monitor would
work and the other would get "colored snow".
This thing is more likely to be a three channel Chinese DisplayLink knockoff. Run Uwe Siebers USBTreeView and get a dump of the composite devices and
what is behind them. Behind the hub might be some Chineseum USB to Display chips using compressed data and some amount of CPU to do it (sloow).
https://www.amazon.com/dp/B08K7GLGYT
The first generation of DisplayLink, the USB2 was heavily compressed
and your sale projector shooting stuff on the wall, was only suited
to PowerPoint. There would be a "pixel wake" until the next slide appeared.
Later USB3 DisplayLink were good enough to play video, but not necessarily
with the highest quality. Video is tolerant of shenanigans.
A DisplayLink can have a fake CD behind the USB Composite item, and that
"loads a Windows driver but not a Linux driver" for one of those display
chips. You may receive a notification on the computer window, that
a CD with an autorun.inf is present. That's the DisplayLink (or Chineseum) driver trying to load.
The displays done that way, are not synchronous to the NVidia, so the
frame change on them is not related to a frame change on the regular
displays. The displays/projectors hosted that way, are
"poor cousins but good enough for a salesman".
*******
The portable display, claims to support video over "USB-C" but
there is no mention of any standards. It is apparently the customer/engineer buying the kit, to figure out all the protocols and whether their machine
works with the shitty item.
https://www.amazon.com/dp/B0BKKLV9HY
Running USBTreeView against that, is unlikely to tell me anything.
Even people in the industry are a bit pessimistic.
https://imagescience.com.au/knowledge/how-to-get-the-right-usb-c-cables-for-your-monitor
So that article refers to an "Alternate Mode", versus full on Thunderbolt passthru.
https://www.benq.com/en-us/knowledge-center/knowledge/usb-c-introduction-what-is-dp-alt-mode.html
"As a consequence, a lot of users with devices that feature USB-C ports
are entirely unaware of whether or not those ports support DisplayPort over USB-C."
And this is why we have a Tech Industry, to make this stuff simple by putting the correct icons next to the connectors.
A rough rule of thumb might be that a desktop is unlikely to be
ready to do it. Only with the equivalent of the (retrofit) Asus
thing (actually made by several motherboard companies for their
motherboards), could you do DP over USB-C (which is likely a Thunderbolt
versus just an alt-mode). Alt-mode might be "repurposing the
differential signals for a completely different protocol".
Paul
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* Origin: A noiseless patient Spider (3:633/280.2@fidonet)
