Performance comparison of Tonatiuh releases 0.9.4 and 0.9.5

One way to quantify the advances in performance obtained with every new release of Tonatiuh is to compare the time each release of the program takes in tracing the same number of rays throughout the same solar concentrating geometry and sun position configuration.

We decided to do this by measuring the time each new release of the program takes in tracing 6 million rays over the geometry of the NREL Solar Furnace and the sun position configuration defined in the file “SolarFurnace_normal.tnh” that can be found in the Downloads section of the Tonatiuh website at Google code.

Since the execution time of a program strongly depends on the computational capabilities of the computer in which the program is run (i.e., the CPU type, the frequency of its clock, the amount of RAM available, etc.), and in the operating system used, we have selected a sample of three computers in which to measure the time each new release of Tonatiuh takes in casting 6 million rays over the NREL solar Furnace configuration previously mentioned, under both Windows 7 and Kubuntu 9.10.

The results of the comparison between the current release of Tonatiuh (version 0.9.5) and the previous one (version 0.9.5) are shown in the following figure.

From Tonatiuh Blog Figures

From these results the following conclusions can be drawn:

• The two releases of Tonatiuh run almost two times faster under Linux than under Windows. This may be due to a difference in the quality of the executable code generated by the Windows C++ compiler (MinGW) and the Linux C++ compiler (GCC).
  
• Since neither of the two releases make use of parallel computing capabilities within their ray tracing loop they run faster in the computers operating at the higher frequency rates.
  
• The increase in ray casting performance of release 0.9.5 with respect to the previous release of Tonatiuh is substantial. In casting 6 million rays towards the NREL Solar Furnace, it takes of the order of 18.5% less time under Windows 7, and of the order of 6.7 % less time under Linux, than Tonatiuh release 0.9.4.