Last month, Kingston Technology announced the release of a high-performance, low-latency 800MHz DDR2 fully-buffered dual-inline memory modules (FB-DIMMs). This memory kit should look familiar to our readers as we showed you the prototype heat sink last year at the Intel Developer Forum. These modules were built to run on the Intel 5400 chipset, which is the chipset used on the Intel Skulltrail platform. We first spotted the super fast Intel Skulltrail platform at IDF last year and finally got one to benchmark on our test bench in February of this year. The performance numbers of the system were stellar, but it did and still does have a weakness and that would be the memory picked for the system. Intel went with FB-DIMMs on the D5400XS workstation motherboard and while the board was one of the first to support quad channel memory the press kits were sent out with dual channel memory kits. This actually impacted performance, but at the time 800MHz FB-DIMM memory kits were still in development and very expensive. If that wasn’t bad enough, FB-DIMM memory kits run very hot since they have a controller IC on each module. Early adopters of the platform didn’t have too many memory choices when it came to this expensive enthusiast platform, but where there is demand, a product will arise.
Kingston Technology has been developing FB-DIMM memory kits from day one, so it was no shocker when they announced a HyperX part that was unlike any other module on the market. Kingston used a single U-shaped heat pipe to cool the FB-DIMMs’ controller IC. To help transfer the heat away from the heat pipe they then employed a set of nine cooling fins dissipate the intense heat from the controller IC.
Each module has the SPD timings set to 5-5-5-18 with 1.8V on bootup, but the timings may be tightened to 4-4-4-12 with a voltage increase (2.0V). Increasing the voltage on FB-DIMM modules used to be something only dare devils would do, but since the Kingston HyperX FB-DIMMs use an improved heat sink it can now be done safely. For those that want to push the limits with low latency timings we were able to reach 3-4-3-12 timings with full stability with 2.1V. At these voltages you will want to make sure the memory modules have a fan blowing across them!
The Intel D5400XS motherboard has four memory channels that can handle up to 16Gbytes in four fully buffered DIMMs (FBDIMM). FBDIMMs provide better signal integrity but with slightly more latency and are required in most server environments and high-end workstations. In theory, they can provide improved bandwidth over their non-buffered counterparts.
The Kingston 800MHz HyperX FB-DIMMs are significantly taller than standard FB-DIMM memory modules. This can be seen in the above image as the module in front is a standard Samsung 800MHz FB-DIMM memory module with a traditional heat spreader. The Kingston 800MHz HyperX FB-DIMMs are taller and thanks to the innovative cooling system, they can be used together without blocking airflow to the other memory modules cooling fins.
We were curious what memory IC’s were under the heat spreader, so we pulled off the clips and found Elpida branded memory chips with the part number E5108AJBG.