The A6-3400M APU will hit 2.3Ghz on only a few cores (turbo mode) and a light load.
Under a normal multi-threaded, moderately heavy work load it's going to run 4 cores at 1.4Ghz.
i3-2410 CPU will run at 2.1Ghz all the time except when it slows to to save power under a light load.
A i3 CPU @ 2.1Ghz core will do a LOT more IPS (instructions per second) than a APU core @ 2.3Ghz. i3 CPU with 2 cores will do more IPS than A6 with four APUs, which is why it's benchmark scores are higher.