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 |
GSkill Ares Blue F3-2400C11D-8GXM |
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 a 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 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.
From the numbers we managed to achieve, it is immediate that our sample is not a good clocker. For a start, neither of the modules could POST at DDR3-2600 regardless of settings and voltages tried. With Hynix CFR memory chips being able to scale in an almost linear fashion using CL11 up to 1.8V, booting at 1300MHz should have been a walk in the park but for some unknown reason it did not happen in our case. More disappointment comes from the situation in sub-1200MHz modes, which wouldn’t allow G.Skill to sell this particular kit as 2133C9 or 2400C10 with a voltage rating of 1.65V.