Just how bad performing was the slower running cpu L2 cache on the Slot A Athlons faster than 700MHz?

From Wikipedia:

"It became increasingly difficult to reliably run an external processor cache to match the processor speeds being released—and in fact it became impossible. Thus initially the Level 2 cache ran at half of the CPU clock speed up to 700 MHz (350 MHz cache). Faster Slot-A processors had to compromise further and run at 2/5 (up to 850 MHz, 340 MHz cache) or 1/3 (up to 1 GHz, 333 MHz cache)."