we use for a while the IXP425 CPU, in general the chip works as expected. Now we started to use the crypt feature of the NPE.
We crypt 160 bytes packets with AES, each packets takes approx 2.8ms to encrypt. Almost 100% of this time is we wait for the NPE, so the access library on the Xscale seems to be not the problem. We use Version 2.4.
2.8ms for 160 bytes results in a performance of approx 160*8/2.8ms ~ 500Kbit/s. We expect around 10Mbit/s accoring to the tolly report on your website for small packets.
Is the NPE microcode that is on the intel web site an evaluation version with limited crypt speed ?