Is Video RAM a good swap device?

sean4u writes: I use a 'lucky' (inexplicably still working) headless desktop PC to serve pages for a low-volume e-commerce site. I came across a gentoo-wiki.com page and this linuxnews.pl page that suggested the interesting possibility of using the Video RAM of the built-in video adapter as a swap device or RAM disk. The instructions worked a treat, but I'm curious as to how good a substitute this can be for swap space on disk. In my (amateurish) test, hdparm -t tells me the Video RAM block device is 3 times slower than the aging disk I currently use.
What performance do other slashdotters get? Is the poor performance report from hdparm a feature of the hardware, or the Memory Technology Device driver? What do slashdotters use to measure swap performance?