Intel will launch the Pentium III on Friday (2/26/99), releasing a processor that in essence is a P6 core similar to that in the Pentium Pro, Pentium II, and Celeron with SSE added.

Don't skip past that description lightly -- the Pentium III architecture is a Pentium II core with modifications for the new SSE instructions. Same caching, same front-side bus. Initially similar clock speeds. If you don't run software that exploits SSE, you're running the equivalent of a Pentium II. You may have seen other reviews of the Pentium III on the net released before Intel launched the Pentium III chip and released before Intel lifted non-disclosure agreements. Many of those reviews say that the Pentium III technology is comparable to Intel's release of the MMX-enabled Pentium, and conclude that the chip is no big deal.

Before you buy into what they said, consider that those pre-release reviewers were not under NDA with Intel, and did not have SSE-enabled software. We're going to show you here that they completely missed out, sacrificing accuracy and responsible reporting to be first. Far from the yawner they report, the Pentium III is a hot chip with new functionality that will change the games you play.

Here's why the Pentium III will be a winner for gamers and why MMX only had limited impact. The 3D shooters like Quake required a Pentium or later for decent performance because the calculations of what's where in the game all use floating point values. The floating point processor in the Pentium chip was very fast, so it made things possible that couldn't be done with earlier chips. (This is why the earlier AMD K6 chips -- before the 3DNow! improvements -- didn't perform as well: their floating point implementations weren't as fast as Intel's). MMX had no effect on the floating point part of the games, because it was a completely integer-based technology. SSE extends the MMX idea into floating point, avoids the problems MMX presented programmers, and adds the capability for very fine control of how cache memory is used. The result will be that the entire game code base, from world model through triangles delivered to 3D accelerator hardware, can benefit.

Here's a preview of what you should expect: a program provided by Intel that flys a character through a complex 3D environment showed a 2:1 gain in frame rate on our test machine without video card drivers optimized for the Pentium III. The game developers have work to do to exploit the Pentium III, but the payoff is there if they do. (If that weren't true, why would id Software want to be associated with the chip and have shown Quake 3: Arena at the Intel Pentium III preview event?)

The Pentium III ships in a Slot 1 cartridge the same as that for the Pentium II. The unit we tested was an engineering sample of the OEM version of the processor, using a massive heat sink (see the photo at the right) to keep the chip cool. Expect to find cooling fans on boxed retail versions of the chip.

Both the 450 and 500 MHz Pentium III chips are 2 Volt parts. The 450 MHz version requires 14.5A (your motherboard has to comply with VRM specification 8.2-1); the 500 MHz part requires 18A (VRM specification 8.2-3). Intel says the Seattle2 motherboard complies with VRM specification 8.2-5 (but didn't have the differences at hand). Existing BX chipset boards should meet VRM specification 8.2-1, so any should host the 450 MHz Pentium III with no more than a BIOS update.

The Pentium III installs on the motherboard exactly like the Slot 1 Pentium II cartridges, connecting into the motherboard connector while being supported and retained by the plastic clips on either side. The photo at the right shows the Pentium III after installation on the motherboard. The metal rectangle below the processor heat sink is the BX chipset. The white connectors to the left of the processor are the PCI sockets (you can see the AGP socket between the processor and the PCI sockets). The DIMM memory sockets are the black connectors below and to the left of the chipset.