> its especially visible in Linux where dual core
> (even quad core G5 exists)can be used.

Tabor is dual-core as well, so that's one of the few categories where there's no difference when comparing Tabor against MorphOS-supported G5 (which is dual-CPU at best).

> x1000,x5000/020 and even x5000/040 have been tested
> vs G5 and have failed miserably.

In certain performance categories, X1000 (memory bandwidth) and X5000 (non-SIMD integer math) are faster than most MorphOS-supported G5 PowerMacs. Tabor on the other hand is slower than even the slowest dual-CPU PowerMac G5 in each and every performance category, and slower than even the slowest PowerMac G5 in almost all performance categories.