does the usb graphics adaptor work for videos with a lot of action

i have a dell precision m6400 with a nvidia fx 2700 video card (512 k on video card and 8 gig for the cpu)— but it only has a vga output— when i hook it up to my lcd HD sccreen (which has both vga and dvi and hdmi connectors) via the vga — the picture looks washed out---- i want ot use the computer for watching hd videos— and i was wondering if the connector you sell at amazon
Plugable USB 2.0 to VGA/DVI/HDMI Adapter for Multiple Displays up to 2048x1152 Each - DisplayLink DL-195 Chip would work— it gets good reviews— but some suggest it wouldnt be good for video d/t usb connector limits— expecially action movies— can you clarify
peter franks

thanks— that was helpful— at least i know what im dealing with now

Have you conisered a Village Instruments ViDock? These are designed for supporting multi-monitors in gaming or intensive video applications. They are more expensive and you have to get the video cards for the dock, but it should do the job for you. ……

Hi Peter,

Thanks for the question!

To be clear - no, USB graphics is not the right choice if your primary scenario is video playback, especially with a high resolution monitor.

These devices work by sending only the pixels that change over the USB bus to a framebuffer in hardware on the device. The monitor is refreshed at a high rate (not subject to USB bus limitations) out of that framebuffer.

So for scenarios where most of the pixels on the screen are changing, and changing at a high rate, the USB 2.0 bus is an unavoidable bottleneck - at 480 Mbps theoretical (~330 Mbps practical) bandwidth, there’s just no way to update every pixel on a 1920x1080 screen 24 or 30 times per second.

So when you have relatively static content as is typical with the web or business applications - it works great.

But with 3D gaming or HD motion video where every pixel is changing many times per second, not so much.

So based on how you’re describing your scenario, I’m afraid I wouldn’t recommend our product.

Unfortunately, that means if your main GPU is not doing the job (the washout), that doesn’t leave you many options - you may be stuck replacing the laptop to get the quality you’ll want for hd videos.

Sorry for the bad news - but we want to set clear expectations about what USB graphics adapters are good at, and not.

Best wishes and good luck,