Then I tried siege on five node/n paths. Ran this a few times before taking results so that registry/menu cache generation had already been done: Drupal 6: Lifting the server siege... done. Transactions: 629 hits Availability: 100.00 % Elapsed time: 120.10 secs Data transferred: 3.94 MB Response time: 0.08 secs Transaction rate: 5.24 trans/sec Throughput: 0.03 MB/sec Concurrency: 0.44 Successful transactions: 629 Failed transactions: 0 Longest transaction: 0.18 Shortest transaction: 0.06 HEAD: Transactions: 579 hits Availability: 100.00 % Elapsed time: 120.02 secs Data transferred: 5.32 MB Response time: 0.12 secs Transaction rate: 4.82 trans/sec Throughput: 0.04 MB/sec Concurrency: 0.56 Successful transactions: 579 Failed transactions: 0 Longest transaction: 0.31 Shortest transaction: 0.08 Patch (with primed cache): Transactions: 605 hits Availability: 100.00 % Elapsed time: 120.05 secs Data transferred: 5.56 MB Response time: 0.11 secs Transaction rate: 5.04 trans/sec Throughput: 0.05 MB/sec Concurrency: 0.55 Successful transactions: 605 Failed transactions: 0 Longest transaction: 0.24 Shortest transaction: 0.08 Patch (starting with empty cache): Lifting the server siege... done. Transactions: 591 hits Availability: 100.00 % Elapsed time: 119.71 secs Data transferred: 5.43 MB Response time: 0.11 secs Transaction rate: 4.94 trans/sec Throughput: 0.05 MB/sec Concurrency: 0.54 Successful transactions: 591 Failed transactions: 0 Longest transaction: 0.33 Shortest transaction: 0.08 Patch (TRUNCATE cache_path; * 20 during benchmarks): Transactions: 579 hits Availability: 100.00 % Elapsed time: 120.44 secs Data transferred: 5.32 MB Response time: 0.11 secs Transaction rate: 4.81 trans/sec Throughput: 0.04 MB/sec Concurrency: 0.52 Successful transactions: 579 Failed transactions: 0 Longest transaction: 0.25 Shortest transaction: 0.07