Dropping a technology for another

Sep 20, 2007 12:29 GMT  ·  By

Intel's server intended central processing unit, the Xeon family of products, were designed from the start to work best with a special random access memory standard named FB-DIMM that offers high level of computing performance in shared bus architectures, like the one which is currently used by Intel. The downside of that standard is that FB-DIMM memory modules are using a lot more power than traditional DRAM memories and at the same time they are hotter, which poses a whole new series of problems to server manufacturing companies.

Well, after a long time of dedicated support for FB-DIMM memory modules, Intel starts to adopt new standards and in the near future some of its servers, based on dual processing unit motherboards, will slowly but surely begin to offer DDR2 memory support. The choice to implement this extended memory support only for dual processor servers makes sense as the DRAM standard can only accommodate up to 8 memory slots per channel, while FB-DIMM is easily scalable to more than 24 DIMM memory slots.

At this point the biggest hardware architectural gap between Intel and Advanced Micro Devices intervenes as the AMD solutions are based on an integrated on-die memory controller while Intel must go through the memory controller found on the north bridge in order to access all the memory modules.

In all tests, FB-DIMM memories are running hotter and need more power than the DDR2 modules and this trend is increasing as servers are now using increasing amount of random access memory. According to the site geek.com when scaling from 2GB to 8GB of DDR2 modules the energy consumption goes up with around 11W but at the same time when making this move with FB-DIMMs, the energy footprint is going beyond 26 watts.

While Intel claims that its processors are more energy efficient than the solution provided by its rival company, AMD, all such energy savings are quickly negated by the fact that FB-DIMM memory modules that are usually found in Intel based servers need a lot more power that the typical DDR2 memories which are common to the AMD based machines.