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Unformatted text preview: LSU EE 4720 Homework 1 Solution Due: 17 September 2003 Problem 1: Look at the following SPEC CINT2000 disclosures for these Dell and HP Itanium 2 systems: HP: http://www.spec.org/osg/cpu2000/results/res2003q3/cpu2000-20030711-02389.html Dell: http://www.spec.org/osg/cpu2000/results/res2003q3/cpu2000-20030701-02367.html . (Note: Links are clickable within Acrobat reader.) The CPU performance equation decomposes execution time into three components, clock frequency, φ , instruction count, IC, and CPI. For each component determine if its value on the two systems is definitely the same, probably the same, probably different, definitely different. Hint: The answer for the clock frequency is easy, the others require a little understanding of what IC and CPI are. Briefly justify your answers. Clock frequency: The same, the clock frequency is given in the disclosures. Instruction count (IC): definitely different because the benchmarks were compiled with different compilers. CPI: probably different. The HP system is faster, some of that difference may be due to the compiler and some may be due to the system (amount of memory, speed of memory bus, etc.). Both system details (such as memory speed) and compiler details (instruction mix and scheduling) affect CPI and since both are different on the two systems the only way CPI could be identical would be by coincidence. (If the CPIs’ were identical then the HP systems’s better performance would be due solely to the compiler.) Problem 2: Though one may normally think of an implementation as a microprocessor chip, the definition can also include other parts of the system, such as memory and even disk. Why is that important in the problem above? Because the two systems used the same implementation, a 1.5 GHz Itanium 2, but other parts of the system, such as memory and disk, differed and that could lead to different execution times (and CPIs). Problem 3: Differences in ISA, compiler, and implementation all affect the execution time of programs, and the impact of these factors can vary from program to program. For example, an implementation with faster floating point will have a larger impact on programs that do more floating-point computations.faster floating point will have a larger impact on programs that do more floating-point computations....
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This note was uploaded on 08/01/2009 for the course EE 4720 taught by Professor Staff during the Spring '08 term at LSU.
- Spring '08