Sonnet Technologies has announced its 466MHz processor upgrade for 1400-series Apple PowerBooks – the Crescendo/PB G3 466-1M.

The card is the fastest upgrade yet for this breed of PowerBook. As well as its 466MHz PowerPC G3 processor, the upgrade offers a 1MB L2 backside cache.

Together, these supply an eleven-fold increase in performance against the 603e processor originally supplied with this model of PowerBook, the company claims. The upgrade supports Mac OS 7.5.3–9.1, and costs £234 plus VAT.

The product is shipping in the US now. Sonnet's UK distribution is handled by Computers Unlimited.