Product examination and discussion
There are currently two Dominator products being launched by Corsair. One is TWIN2X2048-8500C5D, basically the same as their existing PC2-8500 but with the new heatsink cooling solution, and the product we're testing - TWIN2X2048-8888C4DF - which comes with the new heatsink and Dominator Airflow. We'll show you the modules first.
They're big critters, we know. The PCBs have been extended and above them protrudes the fins of the DHX cooling.
Each module is clearly labelled with its size, along with the frequency and timings it's been tested to run at, providing the host system will allow it.
So how does the cooling work? To help us explain, we'll go back to the cut-out image you saw on the first page of this review.
The outer part of Corsair's new cooling solution is best described as a beefy heatspreader with fins on top (or, as somebody aptly observed, a comb for dear Rys' beard). This makes it more of a heatsink than a heatspreader, where a heatspreader simply distributes the heat along a wider surface area, a heatsink goes some way to actually removing that heat. The outer heatsink interfaces with the BGA RAM chips; the traditional way, if you will.
The PCB has been heightened to make room for a long strip of copper to run across the top of it. This is connected to the ground plane of the PCB. A lot of heat from components ends up being conducted through a PCB, by virtue of the copper tracks running within it. By creating a copper surface on the PCB itself, Corsair is attempting to remove some of the heat that has left the BGAs via the board. The inner heatsinks connect to this copper strip. The end result is that the BGAs are cooled directly through the outer heatsinks and the whole module is cooled by the inner heatsinks.
To ensure that Dominator modules can sit side by side in any system, the cooling has been built up, not out. This does, however, mean that some CPU coolers might get in the way of these modules. We raised this issue with Corsair and they said they were looking into producing a list of compatible products.
Heatsinks trump heatspreaders no matter which way you look at it, but heatsinks with airflow over them are better still. Corsair's Dominator PC2-8888 modules comes with just that...
The Dominator Airflow unit clips over the top of a motherboard's DIMM slots.
Three 40mm fans then blow air down onto the memory modules beneath. Corsair say their DHX heatsink fins have been designed to work best when air blows down onto them. However, even without DHX, Airflow provides extra cooling for any RAM module and as such will be available separately.
There's no speed control for the fans on the Airflow itself, but the fans are powered via a 3-pin connector, with the tachometer lead present, so a motherboard with RPM and temperature based speed control should be able to control the Airflow. During operation, we found the 40mm fans to be fairly quiet.
Ready for some testing?