We've been here before. When Gigabit Ethernet arrived in the late 1990s, network managers could take the order of magnitude leap to true Gigabit or create "fractional" Gigabit links by using multi-port Fast Ethernet and "bonding" software. Now, with 10G Ethernet becoming common on LAN switches, a similar choice awaits us. And it's the same - except that it's different.The part that is the same, naturally, centers on cost. With 10G Ethernet, as with any new technology, initial costs are high. It's not until volumes increase that prices tend to drop.Although with 10G Ethernet, market forces already have seen per-port switch prices "plummet" from the $25,000 range to a mere $13,000 today. So it's still pricey. Knowing that, vendors are typically targeting high-end clustering and data center applications where speed is the need and price is no object.Network interface cards (NIC) of 10G Ethernet aren't inexpensive, either. One of the few "general purpose" 10G Ethernet NICs I could find was the Intel Pro\/10G Ethernet LR Server Adapter. One site will get you this NIC for "only" about $3,500. That's for one - not a 20 pack. Did I mention that it's pricey?Let's also not forget that, currently at least, all 10G Ethernet is optical (and not copper). Even in the Gigabit world, fiber-optic connections are more costly than copper.Now let's look at current Gigabit pricing. I'll grant that when one compares a 24-port Dell or a 3Com fixed-port switch to some high-end datacenter beast, it's not a true apples-to-apples comparison. But, it is a valid comparison in the sense that it provides wire-speed Gigabit connectivity to your servers and endstations.While the "sale ends soon," as I write this piece, a humble, unmanaged PowerConnect 2624 offering 24 Gigabit Ethernet ports can be bought for $299 - or about $12.50 per port.Given that the current price for a 10G Ethernet port is about 1,000 times greater, you definitely have something to think about there. It might be time to "go fractional."From Intel, for example, you can buy a Pro\/1000 MT Quad Port Server Adapter. You get four Gigabit copper ports for roughly $450 - or a little more than $100 per port.In theory, then, for less than $500 - including the four switch ports you'd eat up - you'd get 4G bit\/sec, that is 40% of the bandwidth, for about 3% of the cost of a 10G Ethernet solution.Now there are complications with dealing with multi-port NICs. You need to grapple with "teaming" software to make them act as one. You might require special switching capabilities such as Link Aggregation (which, by the way, our $12.50 per port switch supports). But my point is that with such a jaw-dropping price difference it's worth considering whether fractional 10G Ethernet can do the job for you.Let's not forget, too, what's different. With the rise of 10G, we are hearing serious discussion about things like storage over IP and clustering. To help us reach those goals, we have vendors such as Ammasso and S2IO that are building specialized NICs - that implement advanced features such as Remote Direct Memory Access or TCP\/IP Offload (and more). While they cost more, they do more.So look to use 10G Ethernet and the specialized NICs for the jobs that both are targeted for, but don't overlook the potential benefits of "fractional" 10G Ethernet that you can enjoy today.