PA-RISC Performance against RISC

The main competition of PA-RISC during the 1990s was other Unix platform vendors with their own RISC architectures: Sun SPARC (Solaris), Digital Alpha (Tru64 and OSF), SGI with MIPS (Irix), and IBM POWER (AIX and others). In the late 1990s, Intel Pentium and P6-based sucessors also became serious competitors (Windows and Linux).

While PA-RISC processors were usually faster than their competition at the same clock speed, they were expensive to fabricate. Their platform, HP 9000 on PA-RISC and HP-UX, was usually exclusively priced and was often used for specialized technical workloads that made use of their strengths in floating point and numerical processing,

Companies such as HP and IBM could justify developing very-high-end processor designs, even though the unit volume will be small, because the profits per system are far higher than the profits per microprocessor chip, as MPR put it in 1992.

So, how did PA-RISC fare in benchmark scores of the SPEC suite?

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PA-RISC vs. early RISC and CISC

In the RISC infancy in the late-1980s, PA-RISC was in the 32-bit RISC processors performance midfield. HP PA-RISC got stronger in the early to mid-1990s with higher SPEC scores than competing early RISC designs and improved CISC processors.

Typical PA-RISC SPEC92 and SPEC89 scores
* - approximate
Processor Clock Year SPEC89 SPEC92
int  fp
NS-1 30 MHz 1987 9.5
PRISM 18 MHz 1988 19
PA-7000 50 MHz 1991 49 31 47
PA-7100 75 MHz 1992 107* 82 127
PA-7150 125 MHz 1992 182* 136 201
PA-7100LC 100 MHz 1994 117 144
PA-7200 120 MHz 1995 167 269
PA-7300LC 180 MHz 1996 200* 275*
Based on old SPEC92 archives
* - unsure/unlikely
Processor Clock Year SPEC89 SPEC92
int  fp
MIPS R2000 16MHz 1986 11.8 8.4
DEC KA46 VAX 22MHz 1991 12 11.1 12.6
Motorola 68040 25MHz 1990 10.3 12.2 9.3
MIPS R3000 33MHz 1988 25 20.9 23.4
Motorola 88100 33MHz 1988 18 27.7 18.8
Intel 486DX2 66MHz 1992 25 35.8 16.1
IBM POWER 41MHz 1990 75 40.7 83.3
MIPS R4000 50MHz 1991 36 43.2 42.1
DEC KA49-C NVAX 100MHz 1995 45
Sun SuperSPARC 40MHz 1992 71 50.2 60.2
Intel Pentium 60MHz 1993 60.6 55.1
DEC Alpha 21064 100MHz 1992 59* 74.6 95.2
MIPS R4400 100MHz 1993 73 85.9 93.6
Intel Pentium 100MHz 1995 118.1 89.9
PowerPC 604 133MHz 1995 156.8 144.8
DEC Alpha 21064 200MHz 1994 184 135.8 160.5
DEC Alpha 21064A 266MHz 1993 198.6 262.5
Intel Pentium Pro 150MHz 1996 276.3 220.2

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PA-RISC vs. RISC and IA32

PA-RISC was a fast architecture compared to other RISCs in raw CPU power throughout the 1990s. When others like Alpha and Intel P6 increased frequencies in the late 1990s, PA-RISC soldiered on with lower clock but still high SPEC scores.

Typical SPEC scores of HP PA-RISC computers
Processor Clock Year SPEC95
int  fp		 SPEC2000
int  fp
PA-7000 50 MHz 1991 1.20 2.00
PA-7100 75 MHz 1992 1.53 2.46
PA-7150 125 MHz 1992 3.97 4.61
PA-7100LC 100 MHz 1994 3.76 4.06
PA-7200 120 MHz 1995 6.06 8.14
PA-7300LC 180 MHz 1996 9.22 9.43 87 60
PA-8000 180 MHz 1996 11.80 18.70
PA-8200 200 MHz 1997 14.20 21.40
PA-8500 440 MHz 1998 31.80 52.40 313 321
PA-8600 552 MHz 2000 42.10 64.00 432 433
PA-8700 750 MHz 2001 57.60 85.90 604 576
PA-8800 1 GHz 2004 1001
PA-8900 1.1 GHz 2005
SPEC95 and SPEC2000 scores of other RISC and CISC
Processor Clock Year SPEC95
int  fp		 SPEC2000
int  fp
Sun SuperSPARC 40 MHz 1992 1.13 1.38
DEC Alpha 21064 100 MHz 1992 1.48 2.79
Sun SuperSPARC II 75 MHz 1994 3.11 3.10
IBM PowerPC 604 100 MHz 1992 3.59 3.20
MIPS R5000 150 MHz 1996 3.97 4.20
DEC Alpha 21064A 266 MHz 1993 4.18 6.27
Intel Pentium 100 MHz 1994 4.04 2.35
Intel Pentium Pro 166 MHz 1995 7.11 6.21
DEC Alpha 21164 300 MHz 1998 7.33 12.20 161 158
IBM PowerPC 604e 166 MHz 1996 7.52 8.52
MIPS R10000 196 MHz 1996 10.1 8.7
Intel Pentium II 333 MHz 1997 13.0 9.4
Sun UltraSPARC IIi 333 MHz 1997 14.1 18.3 133 126
Intel Pentium III 500 MHz 1999 20.7 14.7 231 191
MIPS R12000 400 MHz 1998 24.2 43.5? 320 319
DEC Alpha 21264 500 MHz 1998 27.3 57.7 311 382
MIPS R14000 600 MHz 2001 483 499
Sun UltraSPARC III 1 GHz 2001 511 688
IBM POWER4+ 1 GHz 2003 617 862
DEC Alpha 21364 1 GHz 2001 689 975
AMD Athlon XP 2.2 GHz 2002 1080 873
Intel Xeon 2.8 GHz 2003 1249 1081
AMD Opteron 250 2.5 GHz 2004 1619 1652
Typical SPEC scores of HP Itanium computers
Processor Clock Year S’95 SPEC2000
int  fp
Itanium Merced 800 MHz 2001 365 610
Itanium McKinley 1.0 GHz 2002 807 1422
Itanium Madison 1.5 GHz 2003 1315 2106

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Documentation

Most of the SPEC scores are from official SPEC results websites, now archived. Some scores are from vendor product pages, now also archived or lost.

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