I have a complex php web app that on the larger pages will randomly segfault.
My memory operates in ECC Scrub mode and memtest showed no problems on this
machine before it was put in production. CPU's operate cool (for athlons), so
heat isn't likely a problem.
I finally was able to get it to be reliable after trying -O3 through -O1 and
finally just compiling with "-march=athlon-mp -pipe"
Not sure why it's so unstable on this platform, or if anything can be done about
it but it might help someone who finds this bug to figure out how to make it
work. (dual athlon mp 2000+ 1gb ECC RAM)
Not all optimizations are stable on certain platforms, and there is no real way to check.... Be careful on the CFLAGS used when compiling software.