With the introduction of AM2 socket by AMD all new high-end PCs are finally using DDR2 memories. Right now the standard DDR2 speeds are 533 MHz, 667 MHz and 800 MHz, but Patriot was one of the first manufacturers to release 1,066 MHz models. These models are not only targeted to both Intel and AMD overclockers but also to regular users that have an Intel CPU running externally at 1,066 MHz and want to match the memory with the CPU external speed to achieve the maximum performance your system can deliver. Patriot has released a 1 GB kit (PDC21G8500ELK, 2x 512 MB modules) and a 2 GB kit (PDC22G8500ELK, 2x 1 GB modules), both with 5-5-5-16 timings. We will review the 1 GB kit and compare it to its main competitor from Corsair, TWIN2X1024-8500, which is also a DDR2-1066/PC2-8500 1 GB memory kit with 5-5-5-15 timings.

Patriot PDC21G8500ELK DDR2-1066 PC2-8500Figure 1: Patriot PDC21G8500ELK 1 GB (2x 512 MB) DDR2-1066/PC2-8500 memory kit.

Patriot PDC21G8500ELK DDR2-1066 PC2-8500Figure 2: Detail of the sticker found on the reviewed memory modules.

The main problem with DDR2-1066 memories today is compatibility, as only a few motherboards are able to use them to their full potential. On AMD side, as socket AM2 CPUs only support up to DDR2-800, these memories can only be used for overclocking, so there is no point of buying these modules for a socket AM2 CPU if you are not going to overclock it. The regular user that wants to achieve the maximum system performance but without overclocking there are better solutions on the market for this platform, i.e., DDR2-800 memories with lower latencies – Corsair TWIN2X2048-6400C3 is a good example, as it is a DDR2-800/PC2-6400 kit where the memory runs with CL3 instead of CL5.

For the regular user that does not overclock his/her system, the main advantage of DDR2-1066 memories would be using them with Intel CPUs running at 1,066 MHz externally – for example, the new high-end Core 2 Duo and Core 2 Extreme CPUs. If you use DDR2-800 memories with these CPUs, the communication between the CPU and the memories will be taken only at half of the maximum speed it could be used. The problem, however, is that only very few socket LGA775 motherboards accept DDR2-1066. On almost all socket LGA775 motherboards your DDR2-1066 modules will run as if they were DDR2-800, even on the latest ones based on the new Intel 975X chipset.

Of course you can use your DDR2-1066 memory modules for overclocking your Intel CPU: even if your motherboard recognizes it as DDR2-800, you will have memory modules that are guaranteed to run up to 1,066 MHz.

But, just like AMD CPUs, if you don’t plan overclocking your Intel CPU and your motherboard doesn’t support DDR2-1066 but you want to have the fastest memory available, we’d recommend you to pick a low latency DDR2-800 memory, like the abovementioned TWIN2X2048-6400C3 kit from Corsair.

We decided to base our review on Intel side using a Core 2 Extreme X6800 CPU and an ASUS P5B motherboard (Intel 965 chipset), one of the few available today supporting DDR2-1066 memories, in order to simulate the two scenarios: a regular user wanting to use DDR2-1066 instead of DDR2-800 together with a 1,066 MHz external bus (FSB) CPU and an overclocker trying to achieve the maximum clock rate with his/her memory module.

Even though the reviewed modules have official timings of 5-5-5-16, you can lower these timings in order to achieve a higher performance – if your motherboard provides this option, of course.

Unfortunately the motherboard we used didn’t provide this option (even though ASUS may release a new BIOS version enabling this feature).

Patriot provides a lifetime warranty to all their memory modules. If your memory modules burn, just fill out the RMA form available at Patriot’s website and ship your modules to them that they replace the defective modules.

Let’s now take a closer look at Patriot PDC21G8500ELK (DDR2-1066/PC2-8500) memory kit.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.