Comparison of Intel Pentium III and Pentium 4 Processor Performance White Paper | 5 |
On the surface, the architecture of this new class of Pentium 4 processor looks the same as the Pentium III, but after one drills further down, the Pentium 4 is significantly enhanced to give better levels of performance in terms of frequency and instructions execution per clock. These are the two variables that measure the level of how fast an application executes and is defined in the following performance equation:
Performance = MHz (Frequency) x Instructions executed per clock (IPC)
The Pentium 4 processor addresses the two variables in the performance equation with the new underlying silicon/logic implementation of what Intel calls NetBurst micro-architecture. The NetBurst micro-architecture more specifically attacks the frequency and IPC variables of the
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technology, its redesigned architecture of the complete instruction pipeline, its execution engine, and its extension to the existing instruction set. As we move forward through this paper, the benefits of this is will be more clearly explained
More detailed information can be found after the summary section.
Case for Performance
Applications generally can be divided into two classes: 1) floating-point-based applications that are memory- and bandwidth- intensive and, 2) integer-based and basic office productivity applications. Recalling the performance equation mentioned above, the IPCs achievable by the above two classes of applications vary greatly due to the variation of branches in application code. This variation of branches affects the predictability of code flow. A higher probability of correct prediction yields a higher potential IPC and, therefore, higher performance. Floating- point-based multimedia applications tend to have branches that are very predictable and thus have a higher IPC potential. As a result, these applications scale very well with frequency and benefit greatly from the new architecture of the Pentium 4. However, integer-based and basic office productivity applications tend to have more random branches in application code, thus are more difficult to predict. The result is less efficient use of the Pentium 4 architecture on these applications. However, since Pentium 4 processors are available at higher frequencies than Pentium III, performance is still enhanced according to the performance equation.
SYSmark 2001
SYSmark2001 is a suite of application software and associated benchmark workloads developed by Applications Performance Corporation (BAPCO). It is a tool that measures system performance on popular business-oriented applications in the Microsoft Windows operation system. SYSmark contains twelve (12) application workloads that are divided into two categories: Office Productivity and Internet Content Creation.