Logitec DisplayLink-certified USB-to-DVI dongle handles QWXGA
By Darren Murph 
posted Aug 12th 2009 9:46AM
posted Aug 12th 2009 9:46AM
[Via Akihabara News]
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Wouldn't a nice video card with Dual display be a better option....?
These are mainly built for people who can't expand their video card lineup, mainly laptops. In my opinion at least it would be easier to buy one of these than to buy another laptop if I just need the ability to keep a spreadsheet open on the other screen.
Can't cram a new video card into a laptop ...
On a laptop?
....and where would you stuff the large video card into a small laptop?
Oh, I missed that. : )
I guess for a laptop that would be nice.
I assumed being dual display a desktop would be the primary focus.
Running 5 screens on my laptop at the moment. Four are connected to the EVGA UV Plus+ and the 5th is connected to VGA out.
laptop comment
This would be a easy way to add a third monitor for some sweet driving or flying sim action. Two monitors is so 2002.
If that runs in Linux (RHEL) then I'm in for 3...
It says OS X support but idk about Linux.
EVGA UV+ doesn't support Linux, and they have no plans to add Linux support.
@tuaamin13: see http://libdlo.freedesktop.org/wiki/HowTo
hmm, says "Video resolution: 640x480". What does that mean? Does any one know what frames per second does it achieve at full HD? DisplayLink mentioned that these are suitable for "office" applications and they are working for video/gaming suitable solutions
that should read "they are working on a video/gaming solution..."
Think about it... USB bus speed is only 480Mbps (PCI-E is 8GBps and even the SLOWEST PCI is 133MBps)....There is no way you could transfer a constant stream of information @ 1080p resolution over a bus that small. Obviously what this device is doing is upresing the 640x480 (I have never seen a USB videocard get above a true 800x600...)
I don't see how this could push those resolutions, anyone care to explain?
@Grammar
1920x1200 pixels @ 4bytes per pixel = 9,216,000 = 9.2MB = 73Mbpf.
That means that completely uncompressed, the external display at peak USB2 speeds would reach ~6.5FPS. DisplayLink, however, uses compression to achieve slightly better FPS. I currently have the first generation DisplayLink (with poorer, slower compression) and the frame rate is pretty crappy. The next generation that this adapter and the current Lenovo adapter uses promises better refresh rates.
I *believe* that DisplayLink also takes cues from technology like VNC where it actually transfers only "updated" parts of the screen to the adapter which then translates the updates to the screen buffer. Works great for office apps where not much of the screen changes frequently, but terrible for gaming.
sweet! thanks for the explanation Timb!
Logitec? Wait, does Logitech know about this? Man, I thought Japan didn't pull this Chinese crap.
Logitec has been around a long time. Maybe longer than Logitech.
Logitec Japan founded in 1974, Logitech founded in 1981.
Logitech products sound in Japan carry the Logicool brand name.
Logitec was around before Logitech, so Logitech is called Logicool in Japan.
Woops, cake beat me to it. Should've refreshed first! :)
LogitecH? Wait, does Logitec know about this? Man, I thought America didn't pull this Chinese crap.
:P
....and where would you stuff the large video card into a small laptop?
how do these things work? I thought displaylink was a graphics connector format.. does all of the GPU heavy lifting get done by the processor?
I was wondering that too
That's DisplayPort.
These all use chips from DisplayLink.com. This newest version of the chip is faster and supports higher resolutions. Lenovo has had one based on this new chipset out for a while, I've been using it for a couple of months. Works great.
That's displayport.
I just don't get why you would need this. Somebody please explain it's practical uses.
If you have an HDTV that doesn't have a VGA input(like mine), and you want to play emulators & such on your big TV from your laptop.
I would love to play MAME and such on my TV with just a laptop for hardware overhead. Plug in my 360 controller(via USB) and play some classics.
Or do presentations.
Someone has a small form factor PC and needs to connect a second monitor to it.
Something like this would work well with my Dell XPS One 24". The question is how good is the performance.
Based on other displaylink uses (e.g. in USB laptop docking stations with video), the display looks fantastic, but for video the word "choppy" is probably the best descriptor. Several proprietary docking stations (e.g. those used by lenovo) employ displaylink internals.
The good news is that support from displaylink is excellent. They had windows 7 drivers up for download almost as soon as the RC was available, and said drivers work great!
This is significant because it allows you to use two external monitors with a laptop using USB.
The concept has been around for a while, but the higher resolution is relatively new. Lenovo came out with their version about a month ago for $129.
FPS? refresh rate? something? maybe its a slideshow
i don't see how it could be anything other then that...even if it wasn't doing the video processing, a video stream @ 2048 would not fit over a 480Mbps bus.
question: can i plug this into a netbook and use this to play 1080p on the tele? what about games?
MATH Time
(Given no over-head, 8 bpc, 24 bit per pixel )
2,048 x 1,152 x 24 = 56,623,104 bit per frame=54 megabit x 60 fps = 3240 Mbps=3.2 Gbps?
That's 6.75 USB 2.0 max theoretical speed of 480Mbps!
But why bother with DVI? Why not just grab the audio while you're at it and push it out through HDMI? You could always throw in a HDMI to DVI adapter to accommodate those with old monitors.
Because of the bandwidth bus you nincompoop (sorry i love using that word in context)
a USB bus can barely push out video anyway (we are talking 6fps refresh rate max) and you want to put audio on top of that?
I use something similar at work and the refresh rate is horrible. Using 1440x900, I get ghosting and occasional stuck images (have to run your mouse over the screen to get it to refresh).
Not bad if your staring at office apps all day, but forget about using it for entertainment purposes.
USB-connected monitors are not for video or action games. USB just doesn't have that kind of bandwidth.
They are for people who want lots of open browser windows, for people watching lots of stock market activity in real time. Might also be useful for people who need really big fonts and thus lots of screen area.
I'd like to protest them calling the largest format QWXGA. If it were QWXGA, then that should be quad-wide XGA. Normal XGA is 1024x768. Wide XGA is 1280x768. QWXGA should then be 2560x1536.
If all they can do is 2048x1152, then that's pretty much QWSVGA, where SVGA is 800x600, wide SVGA is 1024x600, and QWSVGA is 2048x1200. They're in that ballpark.
Better yet, let's stop using these arbitrary confusing letters and just call it what it is in numbers? The letter way is kind of like the Roman numeral system.
I believe its WQXGA, like WUXGA or WSXGA, and WQSVGA is not a resolution. You cant have a Q and an S.
There are four parts - the base (VGA or XGA), the prefix (S, U, or Q), the possible W to indicate Wide (usually just 16:10), and the possible + to indicate a non-standard resolution.
16:9 resolution tend to be refered to with a P, as in 720p, 900p, 1080p, etc.
not the most precise system, but it makes sense for the most part.
I just don't know what to call 2048 x 1152. 1152p just doesn't have that ring to it
There's also an H, for Hexadectuple, but that's not anywhere near current use. Or for half, which is.
And, mixing multipliers is allowed, although sometimes multipliers are dividers (but I don't think I've ever seen multipliers and dividers mixed.) Example:
QVGA is a divider (320x240,) QXGA is a multiplier (2048x1536.)
And H is so much fun. HVGA is 320x480 (half,) HUXGA is 6400x4800.
Also, QSXGA (quad super) is a standard resolution fair and square - it's used in the medical field.
So, WQSVGA is OK under the convoluted naming system.
But, no, the monitor manufacturers had to define QWXGA as being different from WQXGA. Please tell me how that's any different. (I know why they did it, people wouldn't touch an SVGA resolution monitor today, but just call it 1152p and be done with it, then you don't have the name to deal with. And, it's a 16:9 ratio anyway, so it SHOULD be 1152p, not even WQSVGA.)
Adaptors like this will probably take off in the next year or 2 when usb 3.0 is released. 5.0gbps would be more than enough for a smooth 60fps based on peoples calculations. Assuming of course the device could actually keep up with that. Youll probably be seeing some "External video cards" that everyone with a laptop using integrated video has been begging for for the past couple years.
Is it possible to do better than this using a ESATA port?
eSATA isn't for all peripherals like USB - it's just for drives. eSATA is pretty much just an SATA for in a smaller form factor with a few extra pins. The computer couldn't use eSATA to communicate with an adapter like this - at least not by any regular means.
Lenovo already has this. I ordered mine a few weeks ago for $129 to use on a Macbook Pro to add a second external monitor. Displaylink doesn't have a Mac (10.5.8) driver to run full resolution (2048x1152) yet, but the Windows driver works fine at full res. Good solution if you want to run more than one external monitor from a laptop.
Not only does Lenovo have the USB Dongle, they just came out with a USB Hub with the same video chip for about $30 more.
http://shop.lenovo.com/SEUILibrary/controller/e/web/LenovoPortal/en_US/catalog.workflow:item.detail?GroupID=38&Code=45K1610¤t-category-id=34851FD360E5473EB9DFEB639312E18E
I wonder if they could drop an h.264 decoder chip on there and have a driver to just send compressed video over usb 2. That would allow just about any laptop to play 1080p.
Long term usb 3.0 is needed for sure. If they can make a chip fast enough to push that many pixels then it's all good, but that still doesn't solve the 3d problem.
your mixing up a lot of stuff dude....inorder to push h.264 to the card (live) you would have to encode h.264 on the fly (which is very processor taxing), I don't think any OS/software has been made that is "smart enough" to use the GPU to process video and then send it back to the USB bus, so all the video processing is done on the primary processor.
It would work for pre-rendered video being sent via a proprietary streaming software.
get to work and make it dude. haha