Kingston 6GB Core i7 DIMMs tested and tweaked

Product: Kingston HyperX DDR3-2000 6 GB Core i7 memory kit
Price: £204

DESPITE SOME NAYSAYERS Nehalem-optimised DIMMs did manage in the end to come up with pretty decent performance figures - including top-notch bandwidth reaching DDR3-2000, without straying much from the stock voltage. Both Qimonda and Elpida (oh boy, both very troubled too!) have some lovely 1 Gbit DDR3 chips supporting such frequencies with decent latencies and within 1.5 to 1.65 volts.

Now, Kingston has put together some of these choice chips and impressively tall heat spreaders on an optimised PCB to create HyperX DDR3-2000 six GB tri-channel memory kits for those high end Core i7s we all love oh so much. Here we take a look at the kit in single-DIMM-per-channel setup on an Asus P6T Deluxe reference Core i7 mobo, and Intel's current desktop performance leader, the Core i7 965 while we await the Core i7 975.

We'll also check the dual-DIMM-per-channel setup on the Asus Rampage II Extreme enthusiasts' mainboard.

The installation is straightforward for three DIMMs, even under the tight height limits under the Thermaltake BigTyp 14Pro heat sink – the big silent giant moving nearly 90 cubic feet of air per minute, that we reviewed recently. The HyperX tall heat spreader in this case does help avoid the need for local ventilation of the memory area – some of the CPU fan's spare airflow does the trick.

In the setup, we managed to get the DDR3-2000 CL10 timing at 1.51 volts for DRAM. The problem here was that both the Nehalem core and the 'uncore' portion had to run at 4 GHz because of this. In the normal situation with DDR3-1333 for instance, Nehalem Core i7 cores may run at 4 GHz smoothly when overclocked, but the uncore portion clock (Level 3 cache, memory controller and QPI portion) has to run at double the memory speed setting, i.e. 4 GHz for DDR3-2000.

That seemingly upped the heat from the CPU by about 3ºC alone - so, if running Core i7 with very fast memory, do get some liquid cooling, Thermaltake Xpressar or Asetek VapoChill for your CPU first. The D0 stepping Core i7 975 should partly alleviate the heat problem.

As pushing of latency to CL9 may require much higher memory voltage, we left that attempt to Rampage II Extreme with its three dedicated DRAM power phases. There, at 1.66 volts, we managed to get CL9 DDR3-2000 running with three DIMMs. With all six DIMMs though, all I could get without major setup tweaks was CL8 DDR3-1600, at 1.66 volts as well. By itself, that's not bad, and we're assured we can do more. The ultimate goal is DDR3-2000 stable run across all six DIMMs - watch this space for more on that, including the Windows memory benchmarks.

In summary, Kingston HyperX are darn good-looking DIMMs without heat spreader design overkill, and with pretty impressive performance. Some of the Taiwan vendors are claiming even higher performance on Core i7, like CL8 at DDR3-2133, without stating the voltages though. Don't forget that you'll have to run the uncore, and therefore core, of the Core i7, at a blistering 4.27 GHz or more for that!

The limitations now start to show within the CPUs' memory controller basically. µ

The Good
Good looking, fast, not too warm to the touch
The Bad
Watch out your CPU heat sink clearance height
The Ugly
They do cost quite a bit, though what did you expect?


Bartender's Verdict
9 out if 10