At 11:04 PM 10/22/03 -0700, Lucky Green wrote:

I fail to understand why VIA bothered adding AES support into the CPU. When was AES last the bottleneck on a general-purpose CPU? The bottleneck tends to be modular exponentiations, yet VIA failed to include a modular exponentiation engine. Strange.

Lucky, the VIA chip is for SOHO not servers. Therefore modexp is not a bottleneck, its a "one time" cost well performed by the x86 in a few hundred msec. On the other hand, the AES hardware could provide a substantial relief for the CPU for VPN apps, despite its relative ease in software compared to DES. Remember that the modexp cores out there are generally intended for "high end" apps like commercial-server cards. Though their gate count isn't too bad, they tend to require a large number of RAM controllers and embedded RAM for the operands. If you've got a good fraction of a second to spend, and have a general purpose CPU, you don't need hardware acceleration for modexp. As I wrote previously, I'd expect to see better integrated peripheral support (eg integrated ether or two) before I saw modexp support. --- "The generation of random numbers is too important to be left to chance." -Robert R. Coveyou ORNL mathematician