Jerry Scharf wrote:
One thing I know to watch for is periodic battery replacement. It turns out that running a laptop with a battery in it with AC on all the time will slowly erode the life of the battery. I have no way to know how long you can do this before the batteries won't do what you were expected.
As a single data-point, I have a 3.5-year-old old Dell Pentium-150 laptop in my office that is almost always running off of AC. AFAIK, it is still on the original battery. According to the Windows APM battery meter, it won't hold a charge beyond 85% of capacity. When I run it on battery, I get about 45-60 minutes before the low-battery warnings go off.
The other is that the I/O on laptops sucks compared to PCI. For things that aren't major traffic handlers (like your DNS and DHCP examples) this is not a hit. Do any of the O/Ss out there get full rate out of a 100bT PC card?
According to http://www.pcmcia.org/papers/new_bus.htm (a white-paper on CardBus from 1997), an old-standard (PC Card-16) slot is 8- or 16-bits wide at 8MHZ - similar bandwidth as an ISA slot. The newer CardBus standard allows for a 32-bit channel (muxed address and data) at 33MHz - for a theoretical top speed of 132M/s, similar to 32-bit PCI. CardBus also supports bus-mastering, whereas PC Card-16 does not. IOW, it should be possible for a CardBus (but not PC Card) device in a CardBus-compatible PCMCIA socket to get equivalent performance to a PCI card. I have no clue, however, whether vendors are actually shipping devices that actually make use of all this. -- David