Testing Method & Test Setup

To test the overclocking capabilities of the memory we are going to use Intel’s recently released Haswell platform. As memory overclocks are known to vary between different motherboards, we are going to perform the tests using two different platforms to be sure that our numbers are reliable.

Motherboard	ASUS Maximus VI Gene (BIOS 0607) Gigabyte Z87X-OC (BIOS F5q)
CPU	Intel Core i7-4770K ES @ 4.0 GHz
Graphic card	ASUS GTX 580
Memory	Patriot Viper 3 Black Mamba PV38G186C9K
SSD	Samsung PM840 Pro
PSU	Seasonic Platinum 660 Watts
OS	Windows 7, 64 bit SP1

Even though Haswell is very flexible on the memory frequency one can set, very few people actually do base clock (BCLK) overclocking on their daily setups. Therefore, instead of our previous procedure of fixing the voltage and raising the frequency in 10MHz steps we are now going to fix the frequency and minimize the voltage in 0.01V steps.
As usual, our stability method of choice is HCI Memtest. Since we are dealing with an 8 GB kit, we use eight 750 MB instances and call things stable if we see all of them to go past 100% without showing a single error.
Not to get things too complicated, we only set the primary timings, command rate (1T) and the memory voltage by hand while the rest of the settings is left for the motherboard and SPD to agree on.

Results

Traditionally, our aim is to see how memory reacts to voltage changes and in case with Hynix CFR this reaction translates in almost linear ability to run higher frequencies without having to raise the CAS latency. What comes to second and third entries in the primary timings list, tRCD and tRP, the main factor for lowest stable values of those is frequency, with voltage playing a role only in borderline areas. Lastly, the tRAS value we use in each part of the testing is a sensible value induced by an educated guess.
Whenever we set off for 1300MHz, we couldn’t get the memory to POST. Thinking that we achieved the frequency ceiling we were about to call it a day until an accidental attempt at DDR3-2666 has brought things back to life and we were eventually able to achieve full stability at 1400MHz. Even after a reasonable amount of time, we couldn’t get the memory to POST at DDR3-2600, hence the dotted line connecting 1200 and 1333MHz data points on CL11 and CL12 results.
Obviously, our kit shows lots of potential for stability at high frequencies but, unfortunately, it comes at a price of ultra-loose timings. As a result, pushing things past DDR3-2400 is likely to have a negative performance impact. For simplicity reasons, we don’t provide any timings vs frequency performance comparison in our memory reviews, so we’re going to let the users to play around with this aspect and choose the mode that suits their applications best.
Taking a wider view on situation, we see that this particilar set would fail specs if Patriot wanted to sell it as 2133C11 or 2400C10. In fact, it could barely clear its own rating of 1866C9 with less than 20MHz headroom to spare on the tRCD and tRP limits. This got us thinking; if there are modules that are slightly worse than the ones we have, then those should be going one more step down the spec hierarchy and ending up on DDR3-1600 rated modules, potentially turning those into overclocking monsters.

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Page 1 - Introduction

Page 2 - Closer Look

Page 3 - Photo Gallery

Page 4 - Results

Page 5 - Conclusion