A few days ago I ordered the Matrox DualHead2Go Digital Edition. You are probably wondering what I am talking about. It's a cool device that allows a laptop, or a regular PC for that matter drive two monitors in one of the Windows Vista "Multimon" modes. I've been wanting one for a while now.
I've been watching some internal email discussions on the Lenovo ThinkPad T61p and its use with a docking station to drive multiple monitors. I have seen a number of issues reported around resume issues, the laptop "forgets" it's display configuration, black screen of death, etc. In short, it seems the docking station isn't working out very well for some people. I don't believe the root cause of the issues have been identified. It is not apparent yet if it's the Windows Vista TMM service, Lenovo hardware and drivers, or the video chipset and drivers.
So while the powers that be triage the issues, I got off the fence and purchased my device from jr.com. My shipment arrived late this evening and after cooking some kabobs on the grill, I decided to check it out and see if it worked as advertised. It does.
My first round of tests was with my personal ThinkPad T61p. The picture above is misleading because there is a missing cable that is required. The device is powered and controlled via a USB cable. This is depicted more accurately in the picture to the left.
Input to the unit I have is VGA. Output is DVI. I thought this was a bit strange since it's supposed to be the DVI digital edition. Therefore if you are going to use this with a Mac, you'll have to use the dongle. Since my monitors are already having their input converted via DVI->VGA dongles, I just stuck them right on the unit. I did that because my KVM is VGA.
After installing the Matrox PowerDesk SE software I was able to fully control the display modes desired. I have a Dell 2007FP 20" LCD, and a Dell 2407WFP 24" Widescreen LCD. You can configure the modes a variety of ways, but I set the DualHead2Go to drive the external monitors at 3360x1050 resolution. I was hoping to drive them at 3520x1200 but I haven't yet figured out if it will do that. I think it won't. 3360x1050 looks pretty good. I am planning on replacing the 20" with another 24" LCD and at that point I should be able to drive the twin 24" displays at 3840x1200 which would be the native resolution of both displays.
The next set of tests I ran involved my el cheapo KVM switch. I have the IOGEAR GCS632U which is a 2 port USB VGA switch. For this series of tests, I used my Dell XPS 420 and my work ThinkPad T61p. As before, I installed the PowerDesk software on both machines. I fully expected this to fail but much to my surprise, it works pretty well. The best resolutions for the mismatched monitors ended up being 3360x1050. Matched 24" monitors are looking like the ticket.
The DualHead2Go unit will supposedly drive the two external displays as well as the laptop display for a total of three displays as shown in the screenshot at right. I have not tested that yet. I have also not tested this with my Apple MacBook Pro and OS X 10.5.2. I'll probably get around to both of those tests later and report back.
The USB cable and connection serves two purposes. It powers the unit and provides persistent setting control. When you use the KVM I have, you lose some of the persistent settings on the machine that is not connected via the USB cable. The two settings I particularly like are the setting to specify where dialog boxes are centered, and how applications behave when maximized. Not having full control of either of those settings is a minor nuisance to me. A better KVM switch with full USB uplink support would likely solve that issue long term.
So far I have not hit any issues. I have set all of my machines to suspend and after resume the monitors remember the extended display settings. You can easily drag an application from one monitor to another. I tested HD playback of Windows Vista recorded TV content and that played without issue.
Keep in mind all of my machines are running 64 bit versions of Windows Vista Ultimate so I assume this is going to work with the x86 versions as well. Pretty impressive technology. The unit itself is pretty small so if you want to take it on the road for a trade show or conference, this will be a handy gadget for booth demos. I'll update this post in a few weeks after I get another 24" LCD panel and have a chance to test the twins.
For those of you that want multimon but don't want a full docking station, this is an interesting option. Now obviously it doesn't have the drive bays, USB ports and other docking station features, but if your main goal is to drive multiple monitors, it works rather well. Be sure to check out the compatibility wizard to see if your laptop or desktop will work.
[UPDATE for 5/12/2008] Bad news. Although this works well directly connected to my ThinkPad T61p, or via my KVM switch, I noticed an unacceptable amount of degraded performance on live and recorded HDTV playback on the Dell XPS 420. I’m pretty sure this was due to the Matrox driver that is installed and in use. Your needs may be different. If you want dual monitors for a laptop, this is certainly an attractive alternative to a docking station.