by Ilya Gavrichenkov
11/17/2005 | 03:34 PM
Not so long ago we started paying special attention to DDR2 SDRAM overclocker’s memory modules. As a result we have already offered you a couple of detailed reviews, where we discussed the features and performance of a few overclocker’s memory kits from the most popular memory makers of solutions targeted for hardware enthusiasts. Even though no one will argue about the fact that DDR2 technology is very promising, our reviews of DDR2 memory products didn’t win all the readers’ attention we would expect them to. Looks like most hardcore users interested in the latest and greatest stuff from the hardware market are still favoring AMD CPUs, which explains the relatively calm attitude towards DDR2 SDRAM. As you know this type of memory is currently used only by the contemporary Pentium 4 platforms.
However, in the nearest future the majority of users will change their mind and give due credit and attention to DDr2 SDRAM. There are a few reasons that are going to determine this change. One of the most important ones is the higher working speeds and broader availability of DDR2 products that are just around the corner. Moreover, the price of DDR2 memory modules has already decreased significantly, so that we cannot claim that this promising memory a whole lot more expensive than the standard DDR SDRAM any more.
All in all, there is not a single worthy reason for us to refrain from paying due attention to DDR2 SDRAM solutions, so we decided to enlarge our experience with these products and got down to testing a few corresponding solutions. Today we are going to tell you about overclocker’s memory modules from one very well-known memory maker – Kingston Technology Company. Before we start, I would like to mention that the memory products from this manufacturer are among the most widely spread memory solutions in the today’s market, so we regret sincerely that we didn’t manage to get to test this great memory earlier. Today we are going to correct our mistake and reveal a lot of interesting details about the Kingston HyperX KHX7200D2K2/1G memory. This article promises to be even more interesting because our today’s heroes from Kingston, the DDR2 overclocker’s memory modules, do not resemble the DDR2 overclocker’s solutions from Corsair, Crucial, Mushkin and OCZ, which we have already reviewed before (for details see our articles called DDR2 SDRAM for Overclocking Fans: Getting Beyond 1GHz and Crucial Ballistix PC2-8000 (BL2KIT6464AA1005) Memory Modules Review).
Kingston Company was very kind to give us the opportunity to test one of their fastest DDR2 SDRAM memory kits targeted for overclocking fans. The kit is intended for systems with a dual-channel memory controller and includes two identical DIMMs, each 512MB big. Kingston HyperX KHX7200D2K2/1G kit is shipped in a small plastic package, which also contains a brief installation manual.
As you can see from the name of the kit this memory belongs to the HyperX series, which has been developed specifically for overclocker’s systems. The evident peculiarities of the HyperX series modules are the aluminum heat-spreaders covering the memory modules from both sides. These heat-spreaders are designed in a traditional way: most overclocker memory makers use the same heat-spreaders for their products, too. However, the heat-spreaders on Kingston’s memory modules are of blue color (they use special anodization technique for bringing the color on) and are decorated with the company logo, DDR2 logo and HyperX name. This adds to the unique exterior looks of these memory modules.
The heat-spreaders are securely fastened on top of the memory chips due to sticky conductive tape and are also locked with steel brackets. Each memory modules has a special sticker that marks that these modules belong to KHX7200D2K2/1G series and carries some technical details, which will hardly be of much help to the majority of users.
Although the marking of each memory module suggests that they have something to do with 1GB capacity, you shouldn’t be misled, as in reality it is referred to the entire kit, not to an individual module. In other words, the memory modules you see on the photographs are of 512MB capacity each.
The sticker on the plastic package of the Kingston HyperX KHX7200D2K2/1G memory kit is more informative. It contains the product part number and its major specifications, such as: capacity, number of modules in the package, speed and memory type.
If we combine this info with the data we managed to get on the manufacturer’s web-site we will get a full formal specification of this product. Although, I have to admit that there were a few contradictions here: the package sticker features CAS# Latency 4, while the manufacturer’s web-site suggested it is CAS# Latency 5.
The second value is most likely to be the correct one. Here is the formal technical specification of the Kingston HyperX KHX7200D2K2/1G DDR2 memory kit:
I would like to stress right away that the specifications we have just seen are somewhat different from what we could see by overclocker’s memory solutions offered by Kingston’s competitors. Most products of the kind support 1000MHz nominal frequency (PC2-8000), while Kingston set the nominal frequency of its modules to 900MHz (PC2-7200). And it is with even less aggressive timings of 5-5-5-15! Maybe it can be explained by the fact that the nominal voltage all Kingston HyperX KHX7200D2K2/1G memory modules are tested with during the production process is set to 2.0V. As you know many other manufacturers have no problem setting the nominal voltage to 2.1V and even 2.2V. However, I honestly don’t think that Kingston reduced the speed parameters on purpose, especially today when the competition in the memory market has become really aggressive. I believe that we should look deeper at the roots of things if we want to find out why the specification of these memory modules is so much different from the specs of alternative solutions from other memory makers.
And where are these roots in our case? Well, they are right under the heat-spreader. Here I would like to specifically stress that the sticky conductive take Kingston uses to fasten the heat-spreaders to the chips is of excellent quality. As we will see during the test session its conductive features are truly great, but besides that it holds the heat-spreader in place with perfect security. It turned out a tricky task to remove the heat-spreaders from the Kingston HyperX KHX7200D2K2/1G memory modules. However, our curiosity was overwhelming, so finally our efforts were rewarded :) When we removed the heat-spreaders we discovered that the DDR2 SDRAM Kingston HyperX KHX7200D2K2/1G memory modules are based on Infineon chips. Their full marking is HYB18T512800AF3S.
This turned out a sensational discovery for us: it was the first time we saw these chips in an overclocker product. Moreover, all other memory manufacturers of well-overclockable DDR2 SDRAM solutions have always used Micron D9DQT chips in their modules. Does it mean that Kingston engineers managed to find a worthy alternative to the good old Micron chips?
According to the specification, Infineon HYB18T512800AF3S are intended to support CAS# Latency 5 at 667MHz frequency. However, it doesn’t really mean anything yet. The official specifications of the Micron D9DQT chips are exactly the same.
As for the information we managed to read from the SPD of these memory modules, there is nothing that would indicate their higher overclockability.
The SPD of these memory modules contains timing settings for all DDR2 frequencies approved by JEDEC. If we believe the screenshot above, Kingston HyperX KHX7200D2K2/1G can work at 400MHz with 3-3-3- timings, at 500MHz with 4-4-4 timings, and at 667MHz with 5-5-5 timings. In fact, this is none other but the Infineon memory chips characteristics, these memory modules are built with. However, the memory modules SPD should first of all minimize the number of compatibility issues when the memory module is first installed into the motherboard. Therefore, SPD should contain the timings settings, with which memory modules are guaranteed to work at the DDR2 nominal voltage of 1.8V. This task is definitely fulfilled by the SPD of Kingston HyperX KHX7200D2K2/1G memory DIMMs, because it contains exactly the official chips specification data.
Overall, I would like to specifically point out that Kingston engineers did a very good job on filling out the SPD data. Besides the “correct” timing settings, you can also find the time these memory modules were manufactured and their unique part number.
To test the overclocking potential of Kingston memory kit, we assembled the following platform:
The motherboard BIOS settings were as follows:
This is exactly the same system as the one we used for our tests of other overclocker’s memory modules. Therefore, we will be able to compare the results we will obtain today with the performance of the competitor’s solutions, to get a clearer picture.
We tested the memory for stability in two steps. At first we resorted to the Memtest86+ utility version 1.60 to make sure there were no errors during operation. Then we reconfirmed this result by running S&M 1.7.2 and Prime95 24.13 utilities in Windows XP. This two-step approach ensures that we get trustworthy results.
We tested Kingston HyperX KHX7200D2K2/1G memory kit at 2.0V nominal voltage. I have to say that most motherboards out there, even those not positioned as overclocker’s solutions do support this DIMM slots voltage. Therefore, we will be able to use these overclocking-friendly memory modules in a much wider range of systems, which is their indisputable advantage.
So, here come the results. The diagram shows the maximum frequencies we managed to achieve with different timing settings.
In fact, I don’t think we can call these results impressive. The records set by the overclocker’s DDR2 memory modules built with Micron D9DQT chips outpace significantly the performance of Kingston HyperX KHX7200D2K2/1G. Unfortunately, Infineon chips didn’t turn into a remarkable alternative to the Micron D9DQT that has stood the test of time already. Although, there is no reason for drama.
Of course, the major drawback of Kingston HyperX KHX7200D2K2/1G memory modules is the fact that they didn’t work with the most aggressive timing settings of 3-2-2-8. Besides, their working frequency with the timings set to 3-3-3-10 leaves much to be desired. Looks like these memory modules will suit better for reaching higher working frequencies rather than supporting aggressive timing settings. By setting the timings to 5-5-5-15 we managed to reach 908MHz, which is pretty good.
We cannot deny that DDR2 overclocker’s memory modules from other manufacturers can reach 1GHz frequency at these timings already, but Kingston HyperX KHX7200D2K2/1G supports lower voltage, which is a definite advantage. Lower voltage ensures better compatibility, lower power consumption and heat dissipation, and guarantees less aggressive working conditions for the memory chips and the chipset memory controller.
Moreover, according to the results you can see on the diagram above, we cannot state that we have already exhausted the entire performance potential of our today’s hero. No one can actually prevent us from increasing the memory slots voltage and reach higher working frequencies. And this is exactly what we did. We increased the voltage on the memory modules to 2.3V (this is the maximum Vdimm value you can set on ASUS P5WD2 Premium motherboard without performing any modifications) and decided to see if Kingston HyperX KHX7200D2K2/1G memory kit will be able to reach the 1GHz bar (with 5-5-5-15 timing settings), just like the overclocker’s modules from Corsair, Crucial, Mushkin and OCZ.
However, Kingston HyperX KHX7200D2K2/1G reacted in a very strange way to the voltage increase to 2.3V. While with 2.0V these memory modules worked perfectly fine at 900MHz with 5-5-5-15 timings, the increase in memory voltage resulted into dramatic instability even at this frequency. To tell the truth, this is a pretty curious phenomenon, I should say: we haven’t seen any DDR2 SDRAM modules behave like that yet. By reducing the frequency little by little at the same 2.3V voltage we managed to find out the maximum frequency Kingston HyperX can work stably at: 848MHz. In other words, Kingston HyperX KHX7200D2K2/1G modules based on Infineon HYB18T512800AF3S chips act completely different from their fellows based on Micron chips. In this case, increasing the voltage will not help improve the overclocking potential of the memory modules.
Now that we discovered this regularity, we thought it would make a lot of sense to find out what is the most optimal voltage setting, i.e. at what voltage will the working frequencies of these Kingston modules be maximal? Therefore, we tested Kingston HyperX KHX7200D2K2/1G at different voltages but with the same 5-5-5-15 timings. Every time we tried to get the maximum working frequency, when the memory modules could operate stably and reliably. Here are the obtained results:
2.2V appeared the critical voltage for Kingston HyperX KHX7200D2K2/1G: this is when these memory modules work at the top of their power. Further voltage increase causes very severe performance issues, as we may see from the diagram above.
At 2.2V our today’s hero managed to reach 976MHz. It is very close to what Micron based memory modules for overclockers could do at the same voltage. But nevertheless, Kingston HyperX KHX7200D2K2/1G gets defeated by the competitors based on Micron chips. This statement would be best illustrated by the diagram where the Kingston performance results are compared against the competitors we have already tested earlier (all memory modules were tested at their nominal voltage, as set by the manufacturer).
Here Kingston HyperX KHX7200D2K2/1G is definitely losing. Unfortunately, Infineon chips didn’t prove up to our bravest expectations and failed to compete with Micron chips even at the least aggressive timing settings. However, if you are looking to set high working frequencies for your memory in the first place, then Kinston HyperX solution will not be yielding to the competitors that much any more.
In conclusion I would like to say that if you would like to read more on the influence timing settings and memory working frequency can have on the overall system performance, you should check out our article called DDR2 SDRAM for Overclocking Fans: Getting Beyond 1GHz .
The 1GB kit from Kingston we have just reviewed turned out a very interesting product. These memory modules are the first DDR2 SDRAM overclocker’s kit built from Infineon chips. These chips determined all the peculiarities of the tested memory.
According to our testing results, Kingston HyperX KHX7200D2K2/1G appear slightly behind their competitors from other memory manufacturers. Although they are a top of the line solution from Kingston available at this point, the alternative solutions from other memory market tend to be faster. With Infineon chips Kingston didn’t manage to make its memory work at 1GHz frequency. Other memory market, such as Corsair and OCZ, do offer 1GHz-ready solutions, however, their products use Micron chips. Moreover, the memory modules we tested today proved unable to work with aggressive timings. So, we cannot recommend Kingston HyperX KHX7200D2K2/1G as an optimal solution for those who hunt for high frequencies and low timings.
However, we shouldn’t forget about some indisputable advantages of the Kingston HyperX memory. They boast excellent compatibility with different motherboards and support low voltage.
So, we can conclude that Kingston HyperX KHX7200D2K2/1G will hardly become the choice for extreme overclocking fans. However, it doesn’t at all mean that Kingston made “bad” memory. Kingston HyperX KHX7200D2K2/1G is a good product, suitable for commencing overclockers and mainstream overclocking-friendly systems.