The SA-725's caching features gave this product an edge: No other device offers caching of Web content via SSL. In addition, the ability to re-encrypt data to back-end servers, also found in the iSD, will allow the SA-725 to move into a broader range of markets.

On the scalability side, the SA-725 runs on CacheOS, which includes a round-robin forwarding mechanism. Using this mechanism, you can negate the need for a secondary Layer 4 load-balancer by configuring the SA-725 to perform the task. All but the SA-725 and iSD 2.0 require a load-balancer to scale beyond a single device. But the SA-725 is also more expensive than its rivals, and a centralized management tool for configuration and management of multiple units is not available.

The SA-725 performed well in our tests, but we had some difficulties during configuration. The documentation we first received was not up to snuff, though the later drafts were much more helpful in configuring the device.

CacheFlow Server Accelerator 725, $19,995. Available: Now. CacheFlow, (888) GO-CFLOW, (408) 220-2200; fax (408) 220-2250. www.cacheflow.com