Since around 2001 I made the switch to digital flat panel displays and never looked back. My first display predated DVI by about a year instead utilizing a Digital Flat Panel (DFP) adapter.
I was always annoyed by the whole Digital <-> Analog <-> Digital process when using an analog VGA adapter with a flat panel. I found it crazy that you had to convert to analog when the display was digital to begin with. All Laptops have always had a native digital interface to their displays. So why should external displays be any worse?
When DVI hit the scene it got much easier, but it’s rare to see a laptop with a DVI adapter (that’s not a Mac of course). This always annoyed me.
Now some docking stations for laptops do have DVI, which is great, but not all (like my Lenovo X61).
The reasons why laptops don’t have DVI adapters? Size. It’s much larger than VGA. Although DVI is backwards compatible with VGA, and Apple has figured out a way to shrink DVI, PC maker still don’t bother and stick to Analog. Another excuse? projectors are mainly VGA at most companies.
If size is a problem, you could theoretically add HDMI ports (which is backwards compatible with DVI) but apparently many laptop makers don’t do this either due to cost and needing to also have VGA (projectors).
Supposedly, DisplayPort will solve this all, but I have yet to see someone like Lenovo move to DisplayPort even though Dell is.
DisplayPort is a digital display interface standard (approved May 2006, current version 1.1 approved on April 2, 2007) put forth by the Video Electronics Standards Association (VESA). It defines a new license-free, royalty-free, digital audio/video interconnect, intended to be used primarily between a computer and its display monitor, or a computer and a home-theater system.
[wikipedia]
In the meantime, what can you do if you want DVI on a laptop that only has a VGA port? And what are the advantages to DVI anyway? Well I like DVI because:
- Ghost Free images (no horizontal or vertical sync)
- No calibration necessary (only brightness and contrast)
- Pixel for Pixel perfection

A few months ago I purchased a novel solution to this problem, a DisplayLink Adapter made by Sewell.
DisplayLink is a company that produces the chipset that supports DVI and VGA over USB and it’s licensed to a number of companies including Samsung, Sewell,
When I first got it I had a number of problems mainly due to their driver. The good news is that in the last few months, their driver support (particularly on Vista) has improved a great deal. In fact when I got the device the driver didn’t even work, but their tech support staff is extremely competent and they fixed the driver in a matter of days.
So how does it work? Well, it’s OK. The main issues I have with it are:
- It uses quite a bit of CPU, and the CPU usage will occasionally spike which interrupts my Bluetooth mouse which I find annoying.
- Occasionally when undocking I get a message saying the USB device is in use and I can’t undock.
- It doesn’t work during boot of course, which means that if you need to interact with your BIOS or say enter your BitLocker PIN you are SOL.
- Max resolution of 1600 x 1200.
I hope that in the future that Windows adds native support for USB style display adapters, but for now, these are some serious limitations.
Furthermore, USB doesn’t have the same bandwidth as DVI so no high frame rate activity like Games. Video works ok (not HD) though.
I should have blogged about this earlier, but I saw Ed Bott referenced DisplayLink on a post about using 3 monitors.
In closing, this technology is pretty good today but not perfect. If you are a VGA snob like me, then this is a viable alternative with some gotchas.