Here's my detective work:
From the Fry's ad:
<< This module is tested and guaranteed to work on motherboards based on the AMD 760, VIA Apollo KT266, VIA Apollo Pro266, ViaP4X266, ALiMAGiK 1 and SiS 735 chipsets. >>
From the Mushkin page for the PC2100 DDR SDRAM:
<< This module is tested and guaranteed to work on motherboards based on the AMD 760, VIA Apollo KT266, VIA Apollo Pro266, ViaP4X266, ALiMAGiK 1 and SiS 735 chipsets. >>
From the Mushkin page for the PC1600 DDR SDRAM:
<< This module is tested and guaranteed to work on motherboards based on the AMD 760, VIA Apollo KT266, VIA Apollo Pro266, ALiMAGiK 1, and Aladdin-Pro 5 chipsets. >>
Clearly Fry's has copied the wording from the Mushkin PC2100 DDR SDRAM page, and not the Mushkin PC1600 DDR SDRAM page.
So I would conclude it is PC2100 at least. Whether High Performance or not, can't say.
I don't know if I could get 100% conviction on this evidence, but could probably convince a majority of a jury of my peers.
WebDude