C. Miscellanea

We encountered several challenges while researching and writing this thesis, many of which had little to do with the research-at-hand. The problem of radically different BIOS images was explained in Section 5.1.5. We also discovered that the Intel Pentium 4 was unable to handle floating point exceptions efficiently unless the multimedia SSE2 registers were used for computation. Otherwise, a 1.7GHz Pentium 4 Xeon (circa 2001) was outperformed by a 200MHz Pentium MMX (circa 1997) on a robust Cholesky decomposition of a random symmetric matrix. [20,35].

The most expensive problem was the repeated air conditioning outages in our computer lab. The root causes ranged from cracked chilled water coils to incorrect software configurations. The final four weeks of computations for this thesis were made possible by renting a portable air conditioner; see Figure C.1. Unfortunately we were too late - within hours of the air conditioner arrival, our file server refused to POST consistently, and shortly thereafter it was never heard from again.

Figure C.1: On the right is a rack of computers, including our nine dual Opteron 242s used for this thesis. On the left is the portable air conditioning unit needed to keep our computers from combusting.