Since our Vengeance™ DDR3 memory kits overclocked well when I tested them originally, I decided to see how well the 16GB kit would overclock. The Vengeance 16GB CMZ16GX3M4A1600C9 kit is high density and uses four 4GB modules, so I chose to pair it with the new 2nd genereation Intel® Core processor family (Sandy Bridge). This new platform allows for memory clock speeds all the way up to 2133MHz. It also has a fairly strong memory controller which is required to run 16GB at high speeds.
For the CPU I chose the Intel® Core™ i5-2500K, along with an ASUS® P8P67 PRO motherboard. To power the machine the Corsair Professional Series Gold™ AX1200 was chosen, along with the Corsair Hydro Series™ H70 for cooling the processor. At stock settings the Corsair Vengeance CMZ16GX3M4A1600C9 kit is rated at 1600MHz, with timings of 9-9-9-24. Just like the previous Vengeance kits I tested for overclocking, these were rated at 1.5 volts. This meant that raising the voltage should allow for even higher overclocks.
After several hours of testing, overclocking the modules to 1866MHz and above seemed possible. However in order to reach these clock speeds, the timings needed to be loosened to 10-10-9-27 and the memory voltage needed to be set to 1.7v. With these settings the memory was able to be overclocked to 1921.8MHz. It was able to easily pass Intel Burn Test for 20 minutes using all 16GB of memory. It also passed HyperPi 32m without any issues as well. This made for a very impressive 321MHz overclock from the stock 1600MHz.
The 1.7v that was required to get the modules to overclock to 1921.8MHz is not recommended to run 24/7 however you can lower the memory voltage to 1.65v and still get great overclocks. With the same timings just the voltage reduced to 1.65v the 16GB Vengeance kit was able to run 1866MHz speeds. This was a 266MHz overclock over stock, something that is not common especially with a high density kit.
I was impressed the 16GB Vengeance kit was able to be overclocked 20% over the standard frequency. It is also impressive is how well it overclocked with all of the memory slots filled, filling all of the slots and overclocking is not something that used to go well together. Even though it required a higher voltage that may not be safe for daily usage, the modules still overclocked well using 1.65v.