I seem to recall it was a SparcStation 10. No clue about the clock speedm but I believe it was more. Note: my first PC was a 386/25MHz, which was considered blazingly fast (and a cool 10k including the Nec MultiSync 3D monitor, a 256 color EGA video card and 24 bit P2200 printer).

PS A different topic altogether, but for quite a while it seemed that whatever clock speeds we gained was wasted on pushing pixels around on the screen...