The Saleae software includes optimizations using the SSE2 instruction set. These optimizations were hand-written to optimize the analog graph rendering, as well as optimize filters.
We do not intend to support CPUs without SSE2. In the future, we do plan to support, but not require more modern SIMD instructions, and at that time, we may add a fall back system to support normal math instructions.
Unfortunately, it's a non-trivial change. Significant changes would need to be made to support falling back - it would not simply be a compiler settings change.
The system requirements have been updated to reflect this:
What are the system requirements for the Saleae products?/139-what-are-the-system-requirements-for-the-saleae-products
trello ID: 56d5bf8fbe33036f006cb249