Accelerated Graphics Port

The test machine initially arrived with an AGP-equipped Matrox Millennium II, which is essentially a port from the PCI version. However, Elonex was also able to provide an AGP card sporting the new X2 technology with Sideband Addressing, the ATI 3D Rage Pro.

To take advantage of more than just the extra bandwidth of AGP, the card will need Windows 95 OSR 2.1, DirectX 5, an appropriate driver, and the AGP VxD. During the testing period, DirectX 5 wasn't yet available, so there was little point in trying to assess any improvement in 3D performance. Windows NT 4 doesn't support Direct3D under DirectX 3. At the time of writing, however, DirectX 5 has arrived and we'll be looking at 3D performance differences in a future issue.

AGP does have performance advantages for 2D. Comparing the Elonex sporting the AGP Millennium II with the machines in this month's Labs, it would have been placed fourth. However, of the machines that are faster, one has a Pentium II/300, another 50ns EDO RAM, and the third 128Mb of RAM, compared with the Elonex's 64Mb. Unfortunately, when I tried running the Elonex with a standard PCI Millennium II, the drivers hung the system on bootup, so I was forced to compare the Elonex to similarly-specified Pentium IIs in the Labs. The comparison implied as much as a ten per cent performance improvement with AGP.

The ATI card also performed well, but not as well as the Millennium II. Its score is no indication that the new X2 and Sideband Addressing technology is delivering any benefit to 2D performance. Clearly, the extra bandwidth and higher sustained throughput afforded by these features are directly aimed at 3D. Fast 3D is all very well, but only a small percentage of PC-using professionals really need it, until the distant future of VRML GUIs arrives. Although Intel tries to highlight the professional application of 3D, this is really only for specific niche markets like 3D animation.

The real application for AGP is gaming. Pentium IIs are currently for the professional, previously Pentium Pro-buying market. But prices are dropping rapidly. The design of the Pentium II makes it much cheaper to produce than the Pentium Pro because the Pro's on-chip Level 2 cache is a more complicated design. Pentium II/233s are already available for less than £1,500, and Intel is dropping its prices almost every month.

Although AGP will initially be available for Pentium IIs only, other chipset manufacturers are already finalising Socket 7 and hence Pentium-compatible motherboard designs. Sample boards should be with manufacturers by the time you read this. This should keep Intel on its toes and help reduce the cost of AGP-empowered systems.

If you've just bought a Pentium II, you might be feeling a little unhappy, especially if you're a 3D professional or games junkie. AGP looks as if it's worth waiting for. Apart from the two cards on test, an AGP version of the Number 9 Revolution 3D (see p178) is also already available, and there are cards promised by a host of other manufacturers. Unless you're desperate for a Pentium II, consider holding off that purchase for more LX chipset-based models to arrive next month.

Author: James Morris