Upgrading to HDMI
Like upgrading to DVI (described in the previous article) upgrading to HDMI is made easier with backwards compatibility. Most computer monitors and graphics cards that have an HDMI port also have a DVI port. But even if they didn’t, you could use HDMI and DVI equipment together, with the full functionality of a DVI connection, by simply using a DVI/HDMI cable or adapter.
One thing to keep in mind, however, is that HDMI is not backwards compatible with analog devices. VGA, or more accurately, D-sub (specifically DE15HD) ports can not be connected to HDMI ports with a cable or cheap adapter. Changing analog signals to digital or digital signals to analog requires a converter that needs its own separate connection to a power source. More importantly, plan on spending 200-400 USD. Finally, you won't be getting anywhere near the quality available from the HDMI monitor or source. You can probably find a mid-range digital product to replace the analog one for less than the price of the converter. And get better results doing it.
So, as we described for upgrading to DVI, you can do it one piece at a time. Unlike the difference between VGA and DVI (explained in the first article) however, HDMI isn’t an upgrade in terms of video quality; you’re just getting a smaller connector with better home theater integration potential. Also unlike DVI, HDMI hasn’t become ubiquitous yet. Insisting on HDMI equipped computer equipment will limit your selection somewhat, though it won’t necessarily increase the price.
There are relatively few graphics cards with an HDMI port, but they are spread up and down the performance and price spectrum, so you can probably find one that suits you. Monitors with HDMI are proportionally more common, but they seem to be concentrated in the mid-range, so you might have to forget about an HDMI screen if you want either the top or bottom of the market.
If you don’t see yourself using the equipment in a home theater context, don’t spend more on HDMI equipped gear. And don’t sacrifice other features you want to get it. Where all else is equal however, you may as well get HDMI’s extra functionality, just in case. If you are planning to integrate the PC and your home theater, though: definitely make an effort to find HDMI equipment.