Introducing Corsair DHX Technology

In case you missed it on Monday Corsair Memory unveiled the latest innovation in high performance module design, Dual-path Heat Xchange (DHX) technology. From the outside it looks like Corsair changed their heat spreader, but it's a bit more complex than a minor heat spreader switch!

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It looks like the PCB is based on the PC2-6400C3 module that overclockers around the world crave and has a taller PCB.  This extra PCB has a partially exposed copper layer that actally connects straight to the a heat sink that will later be attached.  This layer is known at the "thermal pad" and is where the magic happens.

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Due to the thermal pad the Dominator series has four heat sinks attached to each module as you can see in the side view below.

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To get a better view of what all is going on this cut away view is worth a million bucks.

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According to this slide Corsair actually designed the heat sinks to be attached to the PCB by either solder or epoxy.  The production modules will all be attached by epoxy which will allow for easier rework if something goes awry during it's life.

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If you have a heat sink you must have a fan right?  Corsair has a clipped on triple fan cooling unit that will help cool off the heat produced by the memory. Why does all this matter?  Corsair has officially launched DHX XMS2 DOMINATOR PC2-8888 C4 memory. This memory runs at 4-4-4-12 timings at 2.4 Volts, which tends to get warm during periods of long use. Corsair has been able to overclock modules with Dominator heat sinks to over 1250MHz on retail motherboards!

The Internal Performance Numbers

Corsair did publish some performance number with and without the DHX heat sinks and provided them to the press to look over. The first testing they did was using the AMD AM2 platform.

Corsair Memory DHX Technology

The test system was a retail ASUS M2N32-SLI Deluxe motherboard running an AMD FX-62 processor and the latest and greatest modules from their labs.

Corsair Memory DHX Technology

Testing with and without heat sinks showed roughly a 24MHz difference in frequency gains thanks to using heat sinks versus nothing. Corsair is still testing like this and is killing a ton of hardware testing in an oven like this, so the results are taking a long time to achieve.

Corsair Memory DHX Technology

For the next test they ran it on the Intel based ASUS P5WD2 motherboard to look at the thermal aspects of the new heat sink design.  For this they measured temperatures in the middle of the module in slot number three, which is normally one of the hotter modules in the system as it's the furthest away from the airflow caused by the processor and case fans.

Corsair Memory DHX Technology

They didn't test against the Pro or XMS heat spreaders, but did run a test against a module with no heat spreaders at all.  Adding active cooling was good for another 4C as the final test showed. What's all this going to cost you? 

Corsair Memory DHX Technology

If you want the new PC2-8888 modules that run at 1111MHz you will be happy to know they come with the Dominator airflow fan, but also have an MSRP of US $650 with an expected end user price at US $599 as the retailers set their own pricing.

If you like the heat spreaders and don't have $600 to spend on memory Corsair offers the Twin2X2048-8500C5D modules for just $10 to  $20 more than regular heat spreaders would cost you.  An extra $20 for an innovative design like this doesn't seem too bad seeing how it's different from the PCB up. The PC2-8888C4 modules are now the best IC's that Corsair sells besting the sort on the PC2-6400C3's.   Rumor has it that the only 50% of the IC's that pass screening for PC2-6400C3 modules would make the cut for PC2-8888C4.  If we had to make a random guess we would expect the fallout on the Micron IC's would be between 95-97.5% for these modules, which is why Corsair charges so much for these modules.  The IC's that didn't pass screening for PC2-8888C4 modules has to go someplace!

Getting Answers From The Man Behind The Memory: John Beekley

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LR: Welcome John, and thanks for taking the time to talk with us. Tell us a little about yourself, your role with Corsair Memory, and the company itself. 

John: Well, I'll try to keep it short and sweet, since I know that many of your readers are probably pretty familiar with us already. Corsair is quite simply the supplier of the world's finest computer memory, and has been around for twelve years. I am one of the three cofounders of the company, and have worn various hats in Marketing and Engineering. Right now I am VP of Applications Engineering, which means that my crew and I are in charge of product definition, component characterization, technical publications, partner relationships, tech support, web-based knowledge tools, and other fun stuff.

LR: Six months ago Corsair sent out Application Notes number AN601, which tested heat spreader type on the Overclock-ability of a single memory module in a highly controlled environment. It was found that the use of a heat spreaders on modules increase the overclock-ability in all cases. Did you start designing the therminator, later renamed dominator, around this time period? Basically what made you go through with this idea?  

John: We started work on this concept around the same time. Basically, the testing that we did on existing heat spreader types started spurring some serious thinking about what we could do to create a module thermal solution with truly superior performance. So we started brushing up on thermodynamics, doing some designs, and running some experiments.

LR: Corsair has referred to the Dominator modules as having heat sinks. A heat sink is usually a metallic heat exchanger designed to absorb and dissipate excess heat from an object. Can you explain why a heat spreader is not a heat sink and why the DHX based modules have a heat sink?

John: The distinction is perhaps a little subtle. A heat spreader is designed to take heat from a point source and spread the heat over a larger area. A good example is the heat spreader on the CPU, the part on the package that you install the HSF to. A heat sink, on the other hand, is designed specifically to not only absorb and spread the heat, but also to radiate it. And, in my mind, heat sinks must have specific design features for heat radiation, such as fins.

LR: Does this mean that non-DHX modules can?t be upgraded with these heat spreaders?

John: DHX modules have a custom PCB as well as heat sinks. So, while you could put DHX heat sinks on a standard module, you will not get the benefit of the conductive thermal path through the copper in the circuit board. Not something we're really considering...

LR: Are these the first true heat sinks for memory modules?

John: The first heat sinks on memory modules? I'm sure this distinction belongs to something from the mainframe days, perhaps the first solid state computers. In the PC enthusiast world, the Corsair PRO series would have to take that distinction, as its design incorporated fin-like ribs to radiate heat. And, performed pretty well, I might add. DOMINATOR's better though.

LR: The Dominator Airflow brings something old back to being new again. We have seen active memory cooling now for years. I remember using a Thermaltake Active Memory Cooling Kit back in 2002 on my Corsair PC-3200 and PC-2700 memory modules and never noticed a difference. Why are you bringing back active cooling to the enthusiast community?

John: It's pretty simple. Airflow helps dissipate heat. And dissipating heat improves performance and reliability. A small fan with no heat sink is not going to do much good. But a fan unit with three fans that provides impinging airflow to heat sinks that are specifically designed to take advantage of this airflow, that provides real benefits. And we believe these benefits are worth bringing to the community.

LR: Speaking of high performance memory cooling where are the memory module water blocks to use in conjunction with the Nautilus 500?

John: They are still on the drawing board, I'm afraid. Water cooling memory provides some real challenges. Memory sockets are only three tenths of an inch apart, and some popular performance boards use adjacent sockets. That means, you have three tenths of an inch for the memory module and TWO cooling blocks, one for each side. It simply can't be done. Theoretically you could put a long and thin block at the top of the memory, and try to draw the heat up to it. But efficiency would really suffer here. So we are still scratching our heads...

LR: Looking into the future will all high performance Corsair XMS modules feature these heat sinks meaning the end of heat spreaders for Corsair?

John: Our existing heat spreader continues to be very popular with our customer base. I think we'll still be selling that product for quite some time.

LR: Some of our readers are having sticker shock when it comes to the Twin2X048-8888C4DF memory kit, which is priced at $650 MSRP. Can you explain to our readers why such high pricing for your new flagship series?

John: Flagship parts are generally very difficult to produce, it takes extraordinary effort to build them. First, there is lots of engineering time spent developing the necessary RAM screens, then lots of laborious RAM screening that goes into each module. There are inventory issues also - if, say, only 5% of the very expensive RAMs you just bought will yield the flagship part, you need to figure out what to do with the other 95% of the RAMs you just paid extra for. So, a lot of the screening and fallout costs get built into the top-end part.

LR: It?s obvious that not everyone can afford PC2-8888 memory, so what?s in store for everyone else.

John: DOMINATOR materials and assembly are not intrinsically expensive, and will reduce in price as we ramp into volume. Right now we are launching an 8500C5D DOMINATOR that will sell for a premium of only about ten bucks over the non-DOMINATOR part. My guess is that over time, this premium will get even smaller. So, over time our goal is to have a DOMINATOR for every enthusiast system and budget!

I'd like to thank John Beekley and everyone at Corsair for taking the time out of their busy launch schedule to sit down and brief Legit Reviews and our readers about their new technology.  I'm sure you'll see more of John Beekley and I the next time a new innovative product is launched!