Today I received a Sewell Direct USB to DVI adapter which uses the DisplayLink technology. The other day my father received his new iMac and said that I could have my 20" flat panel display back that he had hooked up to his Windows box. At the same time I saw that DisplayLink had released beta drivers for the Mac, so I couldn't resist trying out this technology. I haven't used 2 displays in a long time since I've been using laptops (I don't like using the built in laptop display as a second display as it feels awkward). Installing the drivers was a breeze, but the release notes kind of scared me and I realize that performance is not going to be that of a regular display, but I figured I'd give it a try. I hooked up a Dell 20" display and it was immediately recognized. It seems to work well, but you can definitely notice the lag. I wanted to get it to have fairly static stuff displayed on it like my iChat buddy list, probably some iChat windows and maybe iCal. It won't be very usable to Safari or things that change rapidly. It seems to work OK for mail and even composing a message wasn't all that bad.
I have very high hopes of liking this and if I do, I might have to get another one for a third monitor. Of course, I'll be pushing the limits of USB; I already have 2 USB hubs that are almost filled.
UPDATE: Setting the desktop picture to solid white makes a HUGE speed difference. While this sounds obvious, I just went with the default which is the same picture as on my main display.
Comments
April 12th, 2008
Lewis
Glad to hear this worked out for you. I would suggest that the lag was indeed an issue of a USB i/o bottleneck. I’ve found that (provided I don’t have a bunch of most of my USB ports in use) the lag is almost undetectable. But then, I’m a PC user, so maybe I’m just not as quick to notice performance differences :).
Anyway, we at Sewell appreciate the review.
April 12th, 2008
Scott Gruby
I’ll have to give it a try plugged directly into my MacBook Pro. It may make a difference. Most of my USB devices aren’t in use all the time, so bandwidth may not be an issue. The DisplayLink release notes seem to indicate that performance is definitely an issue. I’m sure if I was on a Core 2 Duo MacBook Pro (and not a 2 year old machine), I’d see a big performance difference. However, I’ve decided to wait until the next round of MacBook Pro updates to bite.
April 13th, 2008
Jason @ DisplayLink
Thanks for the comments. The DisplayLink Mac drivers are definitely still in the beta stage and you’ll find that the Windows XP version is significantly faster. On XP it’s very difficult to tell the difference between a DVI connected screen and a DisplayLink USB connected screen.
We are of course continuing development of the OS X drivers, but it would go a lot faster if we had some support from Apple. If you think that USB graphics for your Mac would be useful, we would appreciate it if you would let Apple know this:
http://www.apple.com/feedback/macosx.html
Also, we always like getting feedback (and bug reports) on our OS X beta. Please feel free to let us know how it’s working for you through our own feedback form:
http://www.displaylink.com/mac
I hope the Sewell adapter continues to be useful to you!
Jason @ DisplayLink
April 13th, 2008
Scott Gruby
While I will leave feedback for Apple, in many cases developers just have to figure stuff out on their own. The company I used to work fro, Critical Path Software http://www.criticalpath.com/ did a lot of work with video drivers and might be able to assist you with optimizing your drivers.
April 13th, 2008
TJ
With a DualHead2Go you wouldn't have any of these performance issues and you could hook up two external monitors to have a symmetrical workspace on your Mac or laptop.
April 13th, 2008
Scott Gruby
If I understand the Matrox solution, the displays must have the same resolution. If that is correct, that wouldn’t work for me as I have a 24” 1920x1200 display and a 20” 1600x1200 display. From my reading of the Matrox specs, the adapter makes the Mac think it has a much bigger display and then splits the signal into 2 displays.
April 14th, 2008
TJ
You’re right, both monitors need to be at the same resolution. You’d have to run your 24” monitor at 1600x1200 (or get yourself another 24” monitor :-)
Personally I find it easier to work with identical monitors.
April 14th, 2008
Scott Gruby
If you’d like to send me another 24” display and one of your DualHead2Go adapters, I’d be more than happy to give it a spin!
(I haven’t used 2 displays in so long, having different sized displays isn’t an issue; one is being used for email, RSS, and IM and the main display is used for web browsing and work.)