Both the Opteron and the Athlon 64 contain 8 extra registers useable only in 64-bit mode, which should increase application performance significantly.

One of the largest problems in modern computer design is the presence of bottlenecks, or areas of low performance which slow an otherwise fast system down.

In most modern computers, data intended for the video and main memory needs to be passed to and through the Northbridge chip on the motherboard, and data from other sources like USB connections, PCI slots or hard-drives must pass through the Southbridge chip, then the Northbridge.

With the amount of information that needs to be squeezed through the various data buses into the processor to be operated on, bottlenecks inevitably develop, where the processor is waiting for the necessary bits to be delivered by the I/O subsystem feeding it.

As processors get consistently faster every few months, while data bus breakthroughs are irregular, the issue perpetuates itself.

AMD has attempted to get around this constant problem by equipping its 64-bit processors with two advantages, internal DDR memory controllers and Hypertransport links. AMD has built the memory controller (normally a part of the motherboard to which the processor is attached), directly into their Opteron and Athlon 64 CPUs.

As you can imagine, this gives a considerably reduces the time it takes the processor to access memory, since while data still needs to travel between the processor and the physical memory, communication with the controller that arranges the data flow does not need to be passed outside the processor, reducing the amount of computing cycles lost while waiting for the memory.

Another benefit is the fact that memory traffic no longer needs to run between the processor and the Northbridge chip on the motherboard which traditionally provides the memory controller, reducing bottlenecks. The second part of the package is support for Hypertransport input/output technology.