AMD strictly moderated (AMD)

[mas]

"A scale-out architecture provides more capacity by adding a greater number of smaller servers, while a scale-up architecture provides more capability by adding a smaller number of larger servers. Workloads that do not share data extensively and can be decomposed and executed in parallel as independent subprocesses are best supported by a scale-out architecture. Workloads that do share data extensively but are inherently multitasked or can be decomposed into dependent parallel tasks are best supported by a scale-up architecture that calls for a more powerful server. For many applications and workloads, both scale-up and scale-out solutions will be technically viable and price/performance ratios will play the final role in IT decision making."

http://www.intel.com/technology/64bitextensions/4071_intel_xeon_rev3.pdf