What's new in the VLSI Microprocessors

Intel has launched new Pentium-4 processor.
The Pentium-4 is fabricated in Intel's 0.18 micron CMOS process. Its die size is 217 mm2, power consumption is 50W. The Pentium 4 is available in 1.4GHz and 1.5Hz bins. At 1.5GHz the microprocessor delivers 535 SPECint2000 and 558 SPECfp2000 of performance. Currently it is the second-performing general-purpose microprocessor. The world champion is Compaq/Digital Alpha 21264B CPU delivering 544 SPECint2000 and 658 SPECfp2000 at 833 MHz. The previous Intel chip, Pentium-III "Coppermine", had 442 SPECint2000 and 335 SPECfp2000 results at 1GHz.
Pentium-4 is the first completely new x86-processor design from Intel since the Pentium PRO processor, with its P6 micro-architecture, was introduced in 1995. Pentium-4' micro-architecture is known as NetBurst. It has many interesting features.
- Compared to the Intel Pentium-III processor, Intel's NetBurst micro-architecture doubles the pipeline depth to 20 stages. In addition to the L1 8 KB data cache, the Pentium 4 processor includes an Execution Trace Cache that stores up to 12 K decoded micro-ops in the order of program execution. The on-die 256KB L2-cache is non-blocking, 8-way set associative. It employs 256-bit interface that delivers data transfer rate of 48 GB/s at 1.5 GHz. The Pentium 4 processor expands the floating-point registers to a full 128-bit and adds an additional register for data movement. Pentium-4' Net Burst micro-architecture introduces Internet Streaming SIMD Extensions 2 (SSE2). This extends the SIM D capabilities that MM X technology and SSE technology delivered by adding 144 new instructions. These instructions include 128-bit SIMD integer arithmetic and 128-bit SIM D double-precision floating-point operations. Pentium 4 processor's 400 MHz (100 MHz "quadpumped") system bus provides up to 3.2 GB/s of bandwidth. The bus is fed by dual PC800 Rambus channel. This compares to 1.06 GB/s delivered on the Pentium-III processor's 133-MHz system bus. Two Arithmetic Logic Units (ALUs) on the Pentium 4 processor are clocked at twice the core processor frequency. This allows basic integer instructions such as Add, Subtract, Logical AND, Logical OR, etc. to execute in a half clock cycle. The integer register file runs also runs at the double frequency. Interesting is that the this method was firstly introduced by Elbrus team in their E2K processor design. The E2K design was described in Microprocessor Report article by Keith Diefendorff in Feb 1999.
For more information on the new Intel Pentium-4 processor see official Intek press-release