SPXN

The same technology that goes into SPX is here: the acclaimed SPX 35-step Gutmann shredding engine. Except this time it ravishes your entire hard drive instead.
If you're in a hurry you can always opt for a 'quick clean', but for those who can only settle for the best, click the 'Weekend' switch.

It may take a while, but nothing can protect you better. The SPX shredding engine was the first available for OS X and it's still by far the fastest and the best.*