700MHz Shoot-Out, Intel comes out on top (Part 1)

AMD beaten in ultra fast chip battle

It no doubt has been quite frustrating to be an Intel employee, watching AMD slowly ratchet up the clock-rate game. Here's plucky AMD, getting all the attention from the computer press. First, it ships the 600MHz Athlon, which easily outpaced the 600MHz Pentium III in most benchmark tests, both synthetic and application based. Then came the 650MHz Athlon, which opened the gap even more. And just recently, AMD announced the 700MHz Athlon, driving Intel deeper into despair. About the only bleak part of this picture for AMD has been the relative dearth of Slot-A motherboards for the upgrade market.

For a while, it looked like Intel was retreating , when in reality, the world's largest chip company was just falling back and regrouping. Now Intel is launching a two-pronged counterattack: one prong aimed right at AMD's weak spot, core-logic chipsets for motherboards, the other aimed right at AMD's key strength, the Athlon CPU.

The core-logic attack was actually supposed to have come last month with the launch of the Intel 820 chipset (code-named Camino). But Intel ran into some snags with the implementation of the new RAMBUS memory on the Camino chipset and thus pushed back its launch. Now it looks like the 820 will be out in late November or early December. The fiasco was embarrassing for Intel due to the last-minute nature of the delay, but it's only a temporary setback.

The second prong of Intel's attack is the launch of the new Coppermine processor line. Although there was some initial speculation as to its final name, the Coppermine CPU will still be called Pentium III. There are two key differences between Coppermine and past Pentium IIIs:

There's now 256KB of on-chip L2 cache. In the old Pentium IIIs the L2 cache wasn't part of the chip but was integrated onto a printed circuit board inside the Slot-1 cartridge. In addition, Intel spent a lot of time tuning the caching algorithms of the Coppermine for greater efficiency. The new CPU is built with Intel's 0.18 micron manufacturing process. This enables the new breed of Pentium III to run at a higher clock rate and lower voltage, and it generates less heat. The actual die size of the new Coppermine is smaller than the old Pentium III (0.25 micron), despite having a far larger transistor count due to the onboard L2 cache.

We had the opportunity to extensively test a 733MHz Coppermine CPU and compare it with a 700MHz Athlon system. The Coppermine ran on an Intel 820 motherboard with 128MB of 800MHz direct RDRAM. At 733MHz, the Coppermine was running with a 133MHz frontside bus and AGP 4x. The Athlon ran on AMD's reference system. We tried running the Athlon on several off-the-shelf motherboards but had fairly serious stability problems, so we stuck with the AMD reference board, which has been very solid thus far. However, the AMD chipset is limited to a 100MHz memory bus, though it does run 200MHz to the north bridge and is limited to AGP 2x. The graphics card used in both cases was a Diamond Viper 770 TNT2 Ultra card running Nvidia's 2.08 reference drivers. The Viper 770 is theoretically capable of supporting AGP 4x.

The Athlon is interesting because it has 128KB of integrated L1 cache, but the L2 cache is offboard, in a manner similar to older Pentium IIIs. Available shipping Athlon processors have 512KB of L2 cache, although AMD claims that later versions will have upwards of 8MB. AMD has been somewhat tightlipped about the cache timings on the Athlon CPUs, however, which seem to vary from one CPU speed grade to the next. Current Athlons are still manufactured with a 0.25 micron process, which means the die size is pretty large. More significantly, a 700MHz Athlon will run quite a bit hotter than a 700 or 733MHz Pentium III.

As noted above, the AMD system was supplied by AMD, and the Intel system by Intel, so neither can be considered an "off-the-shelf" system. Both had identical Western Digital Expert 18.1GB IDE hard drives. The Intel system came equipped with a Hitachi DVD drive, while the AMD test bed had a Toshiba DVD drive. The Athlon came equipped with 128MB of PC100 SDRAM, while the 820 system had 128MB of PC800 SDRAM. (Note that PC800 doesn't necessarily mean the RAM is eight times faster, you can't directly compare the clock rates of direct RDRAM with SDRAM). Both systems had Windows 98SE installed, along with DirectX 7.0. Both cases came equipped with Sound Blaster Live! cards. We used the following tests:

WinBench 99 CPUMark and FPUMark scores. 3D WinBench 99 Processor tests. These benchmarks use a null driver to test CPU performance in two tests. One is a transform-only test, while the other is a transform-and-lighting performance test. The 3D WinBench WinMark score was collected at a refresh rate of 100Hz. GameGauge 2.0 tests (all at 16-bit color) and a subset of GameGauge run at 32-bit color. Q3Test 1.08 run in several different modes.

700MHz Shoot-Out (Part 2)