Hey - the Basho guys were aware and reproduced it pretty quickly. They saw the same response from their new bloom filter branch they're introducing soon too.

I was monitoring with iostat and a couple of other tools. It was certainly very heavy on io, with 80% util, 20% iowait, and that increased as the currency went up.

I was using protobuf, and a w value of 1, so I was out of things to optimize.

When I was inserting objects already in Riak's cache, it ran about 3 times faster, but of course that's not possible with new objects.