## Bar Chart: Performance Comparison Across Architectures and Compilers
### Overview
The image is a bar chart comparing the performance of different compilers (icc, OpenMP 4, ISPC, and Assembly) on three different CPU architectures (IvyBridge-EP, KNC, and Haswell). Performance is measured in GUP/s (Giga Updates Per Second).
### Components/Axes
* **X-axis:** CPU Architectures: IvyBridge-EP, KNC, Haswell
* **Y-axis:** Performance [GUP/s], with a scale from 0 to 8 in increments of 2.
* **Legend (Top-Right):**
* Black: icc
* Red: OpenMP 4
* Black with diagonal stripes: ISPC
* Red with diagonal stripes: Assembly
### Detailed Analysis
**IvyBridge-EP:**
* icc (Black): Approximately 4.6 GUP/s
* OpenMP 4 (Red): Approximately 4.5 GUP/s
* ISPC (Black Stripes): Approximately 5.4 GUP/s
* Assembly (Red Stripes): Approximately 6.2 GUP/s
**KNC:**
* icc (Black): Approximately 6.3 GUP/s
* OpenMP 4 (Red): Approximately 5.6 GUP/s
* ISPC (Black Stripes): Approximately 6.3 GUP/s
* Assembly (Red Stripes): Approximately 8.3 GUP/s
**Haswell:**
* icc (Black): Approximately 1.4 GUP/s
* OpenMP 4 (Red): Approximately 1.4 GUP/s
* ISPC (Black Stripes): Approximately 1.7 GUP/s
* Assembly (Red Stripes): Approximately 2.0 GUP/s
### Key Observations
* Assembly generally provides the highest performance across all architectures.
* Haswell shows significantly lower performance compared to IvyBridge-EP and KNC for all compilers.
* icc and OpenMP 4 have very similar performance on IvyBridge-EP and Haswell.
* KNC shows the highest performance overall, especially with Assembly.
### Interpretation
The chart demonstrates the performance differences between various compilers and CPU architectures. Assembly language generally yields the best performance, suggesting that hand-optimized code can outperform compiler-generated code. The KNC architecture appears to be particularly well-suited for the workloads tested, as it consistently achieves the highest performance across all compilers. The Haswell architecture shows significantly lower performance, indicating potential architectural limitations or optimization challenges for the specific workloads. The similarity in performance between icc and OpenMP 4 on IvyBridge-EP and Haswell suggests that these compilers may be generating similar code for these architectures.
