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For some reason, my new laptop didn't come with a DVI port. What can be done about this situation? I'd like to be able to run a large LCD like the Apple/Dell 24" or 30" monitors - which are becoming remarkably cheap.

USB video

There are various USB to VGA adapters floating around; they're based on the PLX NET2280 part, which is a USB-to-PCI bridge. I'm guessing that that's coupled to a cheap video chip.

Unsurprisingly, people complain about laggy performance. I think that with some work, decent performance could be obtained - even with the 40MB/sec constraint on the NETS2280 chip, there should be enough bandwidth to provide good framerates.

It's still just VGA (not DVI), but there's no reason that a nice video chip couldn't be attached to the PCI side of the NETS2280. Something like the Geforce 5200 would probably improve performance a lot given more hardware acceleration in 2D mode.

I'm tempted to develop such a device myself, but it's a pretty big task.

ExpressCard video

So I have this ExpressCard slot. I have nothing to plug in there; the machine already has a card reader and onboard wireless everything. Theoretically, it should be capable of some pretty decent video performance - even some 3D.

The only problem is, there are no ExpressCard video cards yet. I found a Belkin laptop dock (more info at Engadget) that looks quite promising, but it's not available yet. It's also quite expensive - USD$199.99. No-one has tried the thing, so we don't know what the performance is like. But it looks like an excellent option - it also solves the problem of having lots of cables to plug in when moving.

What about an external high-performance video card, then? If we assume that ExpressCard is about equivalent to a 1x PCI Express bus, then we could actually do some reasonable 3D gaming.

Why not take something like an nVidia 6800, stick it in an external case, and connect through ExpressCard? That way, laptop users can upgrade their video adapters at will. They don't have to suffer reduced battery life when they're on the road. Fitting any sort of reasonable video inside an ExpressCard is a tricky proposition - especially given the typical heat dissipation - but the external case fixes that.

You'd still need an external monitor - but many people would relish the opportunity to run a nice high-res DVI monitor from their laptop. Like me!

Update 12 Dec 2006:

MaxiVista

I tried out MaxiVista for this purpose. It lets you use another network-connected computer as an external monitor. The website has a demo video showing a wireless laptop displaying video on a large external monitor.

I wasn't thrilled about the idea of buying another computer just to run a monitor, but I figured I'd find a use for it anyway.

My actual results weren't quite as promising. Normal Windows stuff worked fine - the performance wasn't stellar, but it would be tolerable. Videos didn't work at all, presumably due to the lack of overlay support in the MaxiVista video driver. SInce one of the main reasons that I want a large external monitor is to run videos, this is no good.

ExpressCard to PCI Express adapter

So I got to thinking about just making a small adapter between the Expresscard and PCIe buses. With that, you could just buy a standard PCIe video card and run it outside the laptop. This partially motivated by the fact that the 30" monitors require dual-link DVI, and the Belkin dock almost certainly won't provide that. They list a maximum resolution of 1600x1200 while there are plenty of normal DVI monitors with higher resolutions.

I did find one adapter - Catalyst Enterprises sells an Expresscard to PCIe adapter at the low low price of USD$275. No thankyou. The adapter appears to be very simple, which gives me hope that I can do something dodgy like solder wires directly from the video card to the ExpressCard plug.

Update 24 Jan 2007:

ASUS XG Station

Apparently, ASUS have announced a widget that will let you plug in an external video card via the ExpressCard slot. They expose it as a 16X PCIe slot. Due in Q2 2007.

Press release here

Pretty pictures here.

The comments going around are interesting. There's two major classes of commenter: the "OMG I NEED THIS NOW" (like me) and "why would you do that, just buy a desktop". I suspect that the former use a laptop as their primary computer, and the latter use desktop and don't know what a nuisance it is to synchronise computers together.

Update 25 Feb 2007:

Using the Dell M1210 laptop with the Dell 2407WFP LCD monitor

A friend suggested that I should go to a Dell store and actually see what the image quality was like instead of assuming that it'd be no good from the VGA port.

I used MonitorTest from PassMark to get an idea of the image quality. There's a little ghosting, but it's generally not noticeable. Running it from an actual DVI source is prettier, of course!

The M1210 has some... oddities... when running at such a high resolution. It's fine at 1920x1080x32bit (framebuffer is a fraction under 8MB), but wants to drop down to 16 bit colour at 1920x1200 (just over 8MB).

Using the NVIDIA drivers, you can get around this by adding a custom resolution. Go to "Add Custom Resolution", plug in 1920x1200x32 bit at 60Hz, and it should switch over without problems. You can verify that you really do have better colour depth by running MonitorTest again and looking carefully at the colour gradients.

The next problem is that the stock Dell/NVIDIA drivers will crash when you unplug the monitor, leaving you unable to actually use the computer without rebooting. The official drivers haven't been updated since June.

To get around this problem, I found LaptopVideo2Go, which lets you use regular NVIDIA ForceWare drivers with mobile chipsets. The latest stable NVIDIA drivers (v93.71) caused bluescreens on my M1210. This forum page suggested the v84.21 drivers, which worked perfectly for me. It remembers the resolution that I had the 2407WFP set to and doesn't crash, so I'm happy. Even the Fn-CRT/LCD key combination works as you'd hope!

One trick that I've figured out when powering up the M1210 is to press the power button and quickly close the lid before the BIOS password screen comes up (assuming you've got the BIOS password enabled). Everything will be set up to use the external monitor exclusively, so you won't have to reconfigure at all.