REVIEWS

10/100 Fast Ethernet PC Card Adapters:
What Bang Do You Get For Your Bucks?

To view theReport card.

We tested the Xircom CreditCard Ethernet Adapter 10/100 and the Silicom 10/100 Fast Ethernet PCMCIA Adapter, as well as a pair of beta CardBus adapters from Digital Equipment Corp. and Xircom (see "CardBus Leaves PC Card in the Dust," on page 94). We also tested the Black Box Corp. Fast Ethernet PC Card, but discovered that it was an OEM version of Silicom's card.

We found that today's offerings are great for 32-bit environments in need of a 100-Mbps solution, though the DOS drivers riding on top of Card Services weren't much faster than a 10-Mbps Ethernet adapter. The verdict: A 32-bit client or operating system will give you a little more than twice the throughput you're getting with your current 10-Mbps Ethernet adapter, but if Fast Ethernet isn't mandated by your netwo rk infrastructure, hold onto your current adapter until 100-Mbps CardBus is an option.

Xircom CreditCard Ethernet Adapter 10/100

Unboxing the CreditCard Ethernet Adapter revealed a PC Card and large external adapter, as well as software drivers and a well-written 180-page manual.

The external connector for the Xircom Card is as big as the card itself and about an inch thick. The cable comes with two LEDs that indicate link status and network activity. Xircom told us that the external adapter was designed to allow users to buy the card as a 10-Mbps adapter that could be upgraded to 100 Mbps. The external connector contains the additional hardware necessary to handle the 100BASE-TX physical layer. In its CardBus adapter, Xircom has consolidated this external connector inside the PC Card.

We plugged the 10/100 CreditCard adapter into our laptop running Microsoft Windows95, and we were pleased to see that the card detected elements and installed itself without a hitch. The Xircom 10/100 card could sustain an average of 16.1 Mbps of traffic, with peaks at 16.8 Mbps. Performance differences between the Silicom card and the Xircom card were minimal.

Getting the Xircom card to function under DOS was a slightly bigger challenge. The DOS install utility requires that Windows 3.1 be installed to detect and set up the card. Since our test machine had only DOS installed, we were forced to set up the card without the install utility. Fortunately, both the manual and the driver programs are well-documented. We had the en tire system up and running in about 20 minutes.

The functions that really put Xircom's card out in front are its driver library, documentation and power usage. In addition to its support for all standard operating systems, the Xircom card ships with IBM OS/2 drivers, a packet driver for DOS TCP/IP applications and a 32-bit ODI driver for Novell NetWare 3.12 and 4.1 and SCO Unix.

Xircom's power consumption was quite a bit lower than Silicom's, running between 370 and 440 milliamps (ma)--a feature that keeps the card cooler and your notebook running longer.

Silicom 10/100 Fast Ethernet PCMCIA Adapter

The Silicom adapter comes in the familiar PC Card form factor, and its external connector is about half the size of Xircom's. The connector houses a Category 5 (Cat 5) connector and link- and traffic-indicator LEDs. At the time we were testing, Silicom said it had no definite plans for a CardBus adapter.

Configuring the Silicom adapter under Windows95 was quick and easy. After installing the software driver, we benchmarked the card with Novell's Perform3. Silicom's card performed equally as well as Xircom's, getting a slightly lower 15.5 Mbps of sustained throughput, with peak performance around 16.75 Mbps.

The Silicom DOS drivers were easy to install, and Silicom includes a DOS-based Wizard to help you along. Like the Xircom card, the Silicom DOS driver ships with an enabler to allow you to run the card without Card Services. Performance under DOS was slightly less than the Xircom card, averaging about 6.5 Mbps during our benchmarks. Silicom's product ships with a driver set that suits most users' needs, but it lacks OS/2 drivers and a 32-bit ODI driver for NetWare.

The Silicom Fast Ethernet PC Card card runs extremely hot. After running our benchmarks, we removed the card and found it was too hot to ha ndle comfortably. Consulting the 33-page manual confirmed our suspicions that the Silicom card consumes considerably more power than the Xircom Credit Card adapter--its rated operating temperature was 10 degrees warmer than the Xircom card.

The manual and drivers lacked the handy verbosity of the Xircom drivers. Fortunately, the Silicom adapter configured itself on the first try, so we didn't need to try and hunt down NET.CFG parameters for its ODI driver.

Joel Conover can be reached at jconover@nwc.com.

CardBus Leaves PC Cards In The Dust

To overcome this limitation, notebook manufacturers have designed a new interface, called CardBus. CardBus comes in the same form factor as a PC Card, but offers a 32-bit architecture, which is a subset of the PCI specification. The result is a new breed of PC Cards that rivals the power and flexibility of PCI cards without compromising the PC Card form factor.

During our test period, we received CardBus adapters from Xircom and Digital Equipment Corp. Both were beta versions, and support for CardBus is still minimal--even on notebooks that are CardBus-ready. Windows95 CardBus support will be available when Windows95 OEM Service Release 2 ships later this fall, so we were limited to DOS Open Data-Link Interface (ODI) testing. The Xircom card ran with fly ing colors, but we were unable to get the Digital card to function with our NEC Versa 6000. Again, at the time we tested, these versions were still in beta.

We used Novell's Perform3 to benchmark Xircom's CardBus adapter, and the results were astounding. The Xircom CardBus 10/100 CreditCard Ethernet Adapter averaged 70.3 Mbps of throughput using a 16-bit DOS ODI driver, with a peak throughput of 86.3 Mbps. That's five times faster than Xircom's 32-bit Windows95 PC Card driver, and 12 times faster than the DOS PC Card. At least two other vendors, SMC and TDK, are pioneering the CardBus frontier with 10/100 CardBus offerings under way.

Increased throughput isn't the only thing you'll notice with CardBus adapters. CardBus shares the same bus-mastering technology as PCI--allowing for bus-mastered DMA transfers, which result in ultra-low CPU utilization even under the most demanding applications. This produces a higher degree of usability and performance for the end user, further pushing the laptop as a sin gle-stop desktop solution.