With the arrival of the new chipsets from Intel, the i915x and i925x, a new memory technology was unleashed in the process. DDR2 made its debut together with new technologies like PCI-Express and Intel’s new LGA775 processors. All of this offer one major performance advantage and that is more bandwidth.
As you know, DDR1 has been around for quite some time now. The transition from SDR to DDR created a significant performance boost to the way we do our computing, gaming, etc. With the introduction of DDR2, can we expect the same thing? First, one has to understand the way SDR, DDR and DDR2 works. SDR works by carrying data only one way, only at the rising point of a clock cycle. DDR does it both ways, both at the rising and falling of each cycle, thus, doubling the bandwidth. That’s why you can see quite a big advantage when the benchmark scores from this 2 types of memory are compared. As for DDR2, it is pretty much like DDR1 except for its 4-bit prefetch feature and of course its ability to work at higher frequencies. It also uses less power compared to its predecessor. Technically with the 4-bit prefetch feature, the read and write is 4 times the amount of data per clock cycle as compared to DDR1′s 2-bit. That’s double the data bus speed. Sounds a lot faster, doesn’t it? But you also have to remember that although DDR2 delivers twice as much data per clock, it is doing it almost twice as slow as well. This is because of its slower latency timings. What this means is that if we compare a DDR1-400 running at CAS 2-2-2-5 to a DDR2-400 running at CAS 4-4-4-10, you’ll probably have the same performance. The DDR2 may deliver twice the amount of data but by that time, the DDR1 has already done a return trip resulting in the same amount of data trasferred as the DDR2.
So why buy DDR2? Well, the answer is scalability. At the moment, DDR2 comes up to 667MHz already. DDR1 cannot scale up to this high due to its limitations. Most DDR2 modules available now operate at stock DDR2-533MHz. Theoretically at this speed, you can expect a slight advantage performance wise over DDR-400 counterparts. But in the real world, it is not always so.
Today we will try and test that theory. Now that DDR2 is already beginning to hit the streets, it would be nice to know what you can expect before taking the plunge. One of the first companies to have DDR2 available in the market is Corsair. As always, this company is always the first in line to deliver a retail product to the performance seekers out there. This company needs no introduction when it comes to producing top notch memory modules. So without further ado, let us have a look at Corsair’s latest DDR2 offering, the TWIN2X1024-5400C4PRO.
Since mid-2003, Corsair has been involved with DDR2 development through the JEDEC association, which establishes industry standards for electronics. Their participation has allowed them to be among the first companies to reach the market with DDR2 memory modules. They’re calling the family XMS2. This particular DDR2 1Gb Matched Pair belongs to the unique Pro Series which features 24 activity LEDs and platinum heat spreaders.
The TWIN2X1024-5400C4PRO is a 1024 MByte matched pair of DDR2 SDRAM DIMMs. This part delivers outstanding performance in the latest generation of DDR2-based motherboards. It has been tested extensively in multiple DDR2 motherboards to ensure compatibility and performance at its rated speed. This memory has been verified to operate at 675MHz at the low latencies of 4-4-4-12.
Packaging is your normal plastic enclosure type. The modules come with instructions in 5 different languages, a current newsletter and a “powered by Corsair” case badge. The modules are a matched pair of Corsair CM2X512-5400C4PRO 240-pin DDR2 DIMMs tested up to 675MHz in high performance DDR2 motherboards. Each module is tested in an Intel-based motherboard before being packaged together.
SPD is programmed at 4-4-4-12 latency values and tested at 1.9V. It defaults at 266MHz (DDR2-533) but is rated at 667Mhz. So there is a lot of headroom for overclocking. Corsair’s high efficiency platinum heat spreader was custom designed for optimum thermal efficiency. Made from cast aluminum, it offers excellent thermal qualities. Through the mini fins, its air surface contact area is maximized and draws away heat from the memory chips for quick thermal dissipation. Corsair says that the new design offers an estimated 95% greater surface area than standard memory heatspreaders. The heatsink is bonded to the memory chips with a thermal adhesive, unique to Corsair, apparently.
Belonging to the Pro Series, we again see the innovative diagnostic LEDs Corsair pioneered. It’s a feature unique to Corsair that gives an instant, at-a-glance estimate of the level of memory activity. While not a performance booster per se, we can’t argue against a feature that looks damn cool in a windowed or clear-case box.
There are a total of 24 Activity LEDs on each XMS2 Pro module, 12 per bank. They line the top edge of the module and displays the real-time memory activity level. These LEDs light up as the level of memory activity increases.
This is definitely Corsair’s strenght based on all our previous experiences with their memory products. Will their DDR2 pick up where their DDR1 left off? We were very confident that there will definitely be heaps of headroom for pushing current hardware to the extreme with these DDR2 modules. Why? Because Corsair’s Twin2X1024-5400C4 PRO are 100% tested at 675MHz before being packaged. But of course there’s no best way to find out but to try it ourselves.
Using our current setup, we were able to push Corsair’s Twin2X1024-5400C4 PRO to a rock solid 321MHz (642MHz-DDR2). The maximum we can get it to run though is up to 334MHz (668MHz-DDR2) but the system was unstable. However, we are 100% sure that it wasn’t the DDR2 memory limiting us but either the processor or its cooling. We have verified though that it can run at its claimed rated speed of 667MHz and probably even more. Now that is indeed very good news for overclockers and enthusiasts aiming to push their systems as far they could.
To find out the potential of DDR2, we overclocked a P4 2.8GHz LGA775 to 3.2GHz (229MHz FSB) to give us a CPU bus speed of 916MHz (FSB916) and a memory bus speed of 305MHz (610MHz-DDR2). We then compared the scores generated from this overclock to a stock P4 3.2GHz LGA775 running with a CPU bus speed of 800MHz (FSB800) and a memory bus speed of 266MHz (533MHz-DDR2). Here we will find out if the future will be great for DDR2 and if it would warrant buying DDR2 modules now and futureproof your investment in the process as well.
Here we can finally see the advantage of having a higher memory bus speed. Imagine what more can Corsair’s Twin2X1024-5400C4 PRO DDR2 do once its full potential is realised when systems having CPU bus speeds of 1066MHz are matched with this DDR2′s 667MHz memory bus.
By now you probably have an idea of what performance gains you can get out of DDR2 through Corsair’s impressive offering, the Twin2X1024-5400C4 PRO. Though it didn’t whip DDR1 as one might have hoped for at stock speeds, it definitely showed us its potential and what it can do for computing and gaming in the very near future. As always, Corsair has never failed to impress us by delivering to the enthusiast market what it asks for, when it asks for.
Overclocking wise, it showed us the gains by moving to DDR2 sooner. With a huge headroom to play with, current systems employing such technology will find that Corsair’s Twin2X1024-5400C4 PRO is what they need to push their systems to the limits. In our case, it’s the other components maxing out before the memory could show how far it can go. With its current rating of 667MHz, these modules will definitely last you till your next few upgrades. If you want more bandwidth now, then there’s only one route to go.
Though the review is about Corsair’s DDR2 offering, it also highlighted the performance difference between DDR1 and DDR2. It showed us what we can get out of the new DDR2 and how it compares to its older brother. Overall, we can say that for those who have just updated to an i865/i875P system and recently bought DDR1 modules for it to wait until your next upgrade. Those who are due for an upgrade soon can either hold on to their DDR1 modules for the time being and spend the money on some other component or sell their DDR1 modules and make the big jump to DDR2 and futureproof their investment. I mean let’s face it, DDR2 is here to stay. It may not provide a huge boost to current systems as when SDR was replaced by DDR at stock settings but when Intel releases its FSB1066MHz processors, expect DDR2 to completely overpower DDR1.
For those wanting the latest DDR2 technology out of their systems, then Corsair’s Twin2X1024-5400C4 PRO is the DDR2 to get. Its stability is nothing short of spectacular. It worked like a dream throughout the entire duration of our testing. If you want to be sure that your DDR2 memory won’t be the limiting factor in your overclocking, then we strongly suggest you order yourself a few sticks of Corsair’s DDR2 Twin2X XMS2 Pro Series. Not only will you have one of the fastest DDR2 out there but also the coolest. A must have for the real enthusiast.