The Microprocessor Report has put together a table of results comparing the performance of Intel Corp’s new Pentium processor against the leading RISC suppliers. It concludes that Pentium is not, as Intel would have us believe, a RISC in complex instruction set clothing. The fact is that the complexity of the iAPX-86 architecture – the variable length instructions, complex instruction formats, multifunction instructions, and so forth – has a pervasive effect on the chip’s design. It is accurate to say that the 80486 and Pentium processors use many of the same implementation techniques as RISC processors, but there is nothing in either processor that can be called a RISC integer unit without distorting the term beyond any usefulness. Although Pentium has roughly the same performance as MIPS Technologies Inc’s R4000, a mid-range RISC processor, Pentium is going into production more than a year after the R4000, and it has about 2.5 times as many transistors, even though the caches are the same size. The Report believes Pentium will cost substantially more than the R4000. On the benchmarks themselves, Pentium outstrips IBM Corp and Sun Microsystems Inc’s fastest processors on integer performance, and is closing the gap with the RISC chips on floating point, although all are still comfortably ahead of the Intel processor with the exception of SuperSparc, which has only a 10% advantage over Pentium.
System CPU Clock Cache SPECint92 SPECfp92 on/off chip
Intel Prototype Pentium 66MHz 16K/256K 64.5 56.9 Compaq Dskp/66M 80486DX2 66MHz 8K/256K 32.2 16.0 DEC 7000/610 21064 200MHz 16K/4Mb 106.5 200.4 HP 9000/735 PA7100 99MHz 0K/512K 80.5 150.6 IBM RS/6000/980 6264 62.5Hz 32K/64K 59.2 124.8 Si Graph prototp R4400 75/150 32K/64K 94.2 105.2 Sun Spcsn 10/41 SuperSpc 40MHz 36K/1Mb 53.2 63.4 Sun Spclassic microSpc 50MHz 6K/0K 26.4 21.0
