• Nick Sabalausky (11/11) Aug 19 2014 Apologies for going so far OT, but couldn't think of a better place to a...
• Justin Whear (10/27) Aug 19 2014 I'm using Plugable's USB 2.0 UGA (model UGA-2K-A). Kernel support has

Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:

Apologies for going so far OT, but couldn't think of a better place to ask.

Anyone know if those USB->VGA devices out there are any good? Also, 
reasonable Linux support with them?

I imagine HDMI->VGA is likely junk, since they'd presumably be limited 
to 60Hz output, which is just masochistic on a true VGA monitor (ie CRT).

But I dunno about the USB stuff. They would essentially be their own 
independent video card, right? Bypassing the PC's internal GPU. Or do 
their drivers take the framebuffer from the GPU and send it out through 
USB? In which case, would there tend to be some display lag?

Heck, I wouldn't even be asking, but it seems that getting native 
VGA-out on a laptop these days limits your options somewhat.

Justin Whear <justin economicmodeling.com> writes:

On Tue, 19 Aug 2014 16:44:50 -0400, Nick Sabalausky wrote:

 Apologies for going so far OT, but couldn't think of a better place to
 ask.
 
 Anyone know if those USB->VGA devices out there are any good? Also,
 reasonable Linux support with them?
 
 I imagine HDMI->VGA is likely junk, since they'd presumably be limited
 to 60Hz output, which is just masochistic on a true VGA monitor (ie
 CRT).
 
 But I dunno about the USB stuff. They would essentially be their own
 independent video card, right? Bypassing the PC's internal GPU. Or do
 their drivers take the framebuffer from the GPU and send it out through
 USB? In which case, would there tend to be some display lag?
 
 Heck, I wouldn't even be asking, but it seems that getting native
 VGA-out on a laptop these days limits your options somewhat.

I'm using Plugable's USB 2.0 UGA (model UGA-2K-A).  Kernel support has 
come and gone with various regressions, but it's working great with 
3.14-2-amd64.  It outputs DVI but comes with a VGA and HDMI adapter--
haven't tried either of them.  I've got it outputting 1920x1080 and 
framerate seems fine, though I haven't tried watching video or anything 
on it.  With past kernels it's been plug-n-play, currently have to 
execute a single xrandr command when I plug it in:

xrandr --setprovideroutputsource 1 0

but it hasn't bothered me enough to track down why.