In addition to providing higher data rates, another significant advantage of the Fly-by approach is that it is highly scalable in that multiple additional DRAMs can be inserted in a system to meet the needs of the relevant applications. With the added DRAMs, the Fly-by architecture is able to maintain high data rates on the Command/Address/Clock signals, whereas other topologies are limited by flight time skew, capacitive loading and impedance mismatches. Such non-Fly-by topologies often must reduce signaling rates on the Command/Address lines to accommodate the added DRAMs, thereby reducing system performance.
When used with FlexPhase circuit technology, the Fly-by architecture allows designers to relax PCB trace length requirements because the timing variations can be managed on the memory module with the FlexPhase circuit technology. Rambus has also developed Dynamic Point to Point technologies that, when used in combination with Fly-by, enable memory upgrades while maintaining bandwidth.
Fly-by architectures enable subsystems that require operational data rates that are significantly greater than those achievable with conventional approaches. Using Fly-by architectures allows designers to relax PCB trace length requirements allowing much simpler and more compact memory sub-system layouts.
In addition, Fly-by architectures provide system benefits by enabling DRAM systems to operate with GHz data rates. This superior DRAM system performance results in improved performance in desktops, notebooks, enterprise servers and storage, HDTVs, gaming systems, and handheld portable devices for end users.