While it was discussed when the Athlon64 first hit, a refresher isn't a bad thing when it comes to the HyperTransport bus. HardwareSecrets has an article up giving the low-down on HTT for the n00b or as a refresher for the more seasoned guru. There's also some info regarding the upcoming HyperTransport 3.0 that should hit with Barcelona. Besides providing AMD64 processors with separated datapaths for memory and I/O, HyperTransport brings another advantage: it provides separated links for the CPU input and output operations, allowing the CPU to transmit (“write”) and receive (“read”) I/O data at the same time (i.e. in parallel). On the traditional architecture using a single external bus since the external bus is used for both input and output operations reads and writes cannot be done at the same time.
