That is the question regarding high-speed switch products.If you're looking to add\u00a010 Gigabit Ethernet to your corporate backbone, you might want to wait for the next generation of switches from vendors such as Cisco, Extreme Networks and Foundry Networks to ensure you're getting the most bang for your buck.That's because most existing Ethernet boxes have a kink: they really only deliver 8G bit\/sec. Vendors will make up for that speed with next-generation chassis upgrades - which could come as early as next year.Although some currently offer 10G Ethernet modules, "most vendors are using switch chassis that were designed three or four years ago to support Gigabit Ethernet," says David Newman, president of Network Test, an independent network equipment test lab and a member of\u00a0Network World's Global Test Alliance."Different boxes are designed in different ways . . . but the most bandwidth many of these products can offer is 8G bit\/sec of capacity" at best, he says. Newman adds that this limitation is because most chassis were designed with 8G bit\/sec interfaces between module slots and the chassis' switching fabric.Another industry watcher says even 8G bit\/sec is generous. Bad implementations of features such as flow control, which regulates the flow of high-speed packet streams to a port, can cause throughput to dip below 7G bit\/sec on some products, according to Brian Tolly, senior engineer and analyst with Tolly Group, a network testing and consulting firm.Price isn't right"For the price that 10 Gigabit is going for," says Sheng Guo, CTO for the State of New York Unified Court System, "I would want to make sure support for 10 Gigabit Ethernet really means I'm going to get 10 gigabits per second."Guo's network connects court and correctional facilities throughout New York over dark fiber and a mix of metropolitan-area Gigabit Ethernet and\u00a0SONET. Guo says that he's found 10G Ethernet to be cost-prohibitive. And the idea that the technology might not deliver as much bandwidth as it promises makes him inclined to put off any tests until vendors can support the real thing.The main reason most boxes don't really support the higher speeds is that switch platforms such as the\u00a0Cisco's Catalyst 6500,\u00a0Foundry's BigIron 15000,\u00a0Extreme's BlackDiamond 6800 and\u00a0Nortel's Passport 8600 have all been on the market for years. The 10G Ethernet standard was only ratified by the IEEE this summer.The limitations of these chassis for handling 10G Ethernet are widely known, vendors claim."We have 8G bit\/sec to each slot on our chassis," says John Erlandson, director of product marketing for Extreme. "That's well-documented, and we've never tried to disguise that in any way."In addition to providing full-duplex 8G bit\/sec, Erlandson adds, Extreme's products also can handle features such as quality of service and multilayer routing without affecting throughput."The performance our customers are getting now, at 8 gigabits per second on one pipe, is eight times as fast as Gigabit Ethernet, and almost as fast as SONET OC-192," which is about 9.9G bit\/sec. However, he adds, the cost for 10G Ethernet is about a quarter the price of its virtual SONET equivalent.So 8G bit\/sec instead of 10G bit\/sec - what's the difference? A lot when you consider 10G Ethernet pricing.Dell'Oro Group says that customers can expect to pay an average of $25,000 per 10G Ethernet port this year. Long-reach 10G Ethernet ports from vendors such as Foundry, Cisco and Extreme can cost in the range of $75,000 to $80,000 for a single port on a module that takes up an entire slot in a chassis.While Dell'Oro expects the per-port cost to drop to around $7,000 in 2005 (still five times what Gigabit cost in 1999), it is expected that the technology will appeal to only the largest shops. IDC expects that only 45,000 10G Ethernet ports will ship this year, as opposed to 8 million Gigabit ports worldwide.Meanwhile, eight 1G ports would cost about $10,000 to $16,000.Ten Gigabit might be on the distant horizon for many corporations, but users looking to make a chassis-switch purchase now could be caught in the middle of a major upgrade cycle by their respective vendors.Coming soon?In conference calls with investors last month, Foundry CEO Bobby Johnson alluded to his company's next-generation core switch, code-named Mucho Grande, which sources say will support more than 10G bit\/sec of bandwidth per slot and is expected to debut next year.Other vendors have hinted that chassis upgrades are around the corner as well."Will we be changing BlackDiamond to accommodate an extra two Gigabits of Ethernet bandwidth per slot? That's very unlikely," says Extreme's Erlandson, who hinted that a successor to BlackDiamond also could be expected next year.Alcatel's OmniSwitch 8800, which was announced in February and is scheduled to ship this month, supports approximately 13.2G bit\/sec per slot, according to the company. Modules with single-port 10G Ethernet ports will be released from Alcatel in the second quarter.Users and analysts say a wait-and-see approach might be wise if 10G Ethernet is in their game plans."If 10 Gigabit is in the long, long-range plan, [users] should work with their vendors and get some [nondisclosure agreement] information and" work out a timetable for when the vendor will release a true 10G Ethernet switch, says Lawrence Orans, senior analyst with Gartner. "If [users] need 10 Gigabit now, they should only make tactical investments on older switching platforms" that are available today.For now, many analysts say market newcomer Force10 Networks is one of the few options for high-density 10G Ethernet switching. "If you want to buy a high-end switch with 10 Gigabit Ethernet, Force10 is really the only option," says Zeus Kerravala of The Yankee Group.Force10, which debuted its E1200 switch in September, says it can provide up to 40G bit\/sec of bandwidth between switch modules in its chassis. The company is shipping dual-port 10G Ethernet cards, which cost about $110,000."But on the other side of it," Kerravala adds, Force10 "is a start-up that's debuting in a market that's very young - and very expensive - while in the middle of a down economy. The question is, are they going to hang in there long enough for the market to come around."For users working on the most cutting-edge network technologies, the performance boost of Force10 is worth any risks.Two Force10 E1200s were recently installed at the San Diego Supercomputing Center (SDSC) to support a cluster of 512 Gigabit Ethernet servers. The servers are part of the Teragrid project, an effort by the SDCS, along with the National Center for Supercomputing, to build the world's largest distributed supercomputer, according to Kevin Walsh, senior network engineer at the SDSC."There is no other manufacturer at the moment that has combined this kind of performance and capacity," says Walsh, adding that he has tested 10G Ethernet switches from other vendors. He did not name specific companies.