SPEC CPU 2000 Integer Performance Analysis
Compiler and other software related changes.
As stated in the original article, factors other than processor architecture and core frequency that influence overall performance include: compiler, bus speed, cache size and other factors.
Figure 1 shows SPECint_base2000 scores for the Pentium 4 processor, 1.5GHz, 256K L2 cache, 400MHz FSB. The November 2000 (Intel C5.0) and August 2001 (IC5.0.1) results are on the Intel D850GB motherboard. The November 2001 (IC5.0.1) result is on the D850MD motherboard and the May 2002 (IC6.0) result is on the D850EMV2. The first measurement used the version 5.0 compiler, the second and third used version 5.0.1 and the last used version 6.0.
Figure 1: Pentium 4 1.5GHz performance with compiler improvements.
Figure 2 shows the SPECint_base 2000 scores for the Pentium 4 2.0GHz/512K processor with the 5.01 (Nov-2001), 6.0 (May-2002), 7.0 (Jan-2003), and 8.0 (Sep-2003) compilers. The motherboards for each system are the 850MD, 850EMV2, and 850EMVR respectively.
Figure 2: Pentium 4 2.0GHz performance with compiler improvements.
Figure 3 shows the Pentium 4 1.5GHz percentage performance change from the version 5.0 to 6.0 compiler, along with other chipset and motherboard refinements. The composite score gain is 6.9%. Five programs show 10% or larger performance gain, but three programs, EON, PERLBMK and TWOLF, show a performance drop.
Figure 3: Pentium 4 performance gain from complier improvements 5.0.1 to 6.0.
Figure 4 shows the Pentium 4 2.0GHz/512K percentage performance change from the version 6.0 to 8.0 compilers. The Intel version 8.0 compiler recovers the performance lost in 6.0 on the twolf application, but not the perlbmk application. The combined overall performance gain from version 5.0 to 8.0 compilers, released over a 3 year interval, is approximately 12%.
Figure 4: Pentium 4 performance gain from complier improvements 6.0 to 8.0.
Processor Frequency
Figure 5 shows the Pentium 4 performance from 2.26GHz to 3.06GHz. All processors have 512K L2 cache, 533MHz FSB and use the Intel D850EMVR motherboard, and the compiler is version 6.0.
Figure 5: Pentium 4 performance from 2.26GHz to 3.06GHz, 533MHz FSB.
Figure 6 shows the Pentium 4 percentage performance gain from 2.26GHz to 3.06GHz. The overall percentage performance gain is 24.3% for a frequency increase of 35.2%. The Eon performance gain is 37.7%, which is more than what should be possible, unless there is some thing else happening. Overall performance gain is 0.69% per 1% frequency increase. The mcf application scales poorly with frequency, indicating that it may be heavily dependent on memory access latency.
Figure 6: Pentium 4 performance gain from 2.26 to 3.06GHz, 533MHz FSB.