Overclocking
Lowest Stable Timings @ 1.35V (Max)
Header Cell - Column 0 | DDR4-3000 | DDR4-2400 | DDR4-2133 |
---|---|---|---|
Corsair 128GB Vengeance CMK128GX4M8A2400C14 | N/A | 14-14-14-28 (2T) | 11-12-12-24 (2T) |
G.Skill 64GB Ripjaws 4 F4-2666C16Q2-64GRB | N/A | 13-13-13-26 (2T) | 11-11-11-22 (2T) |
Adata 32GB XPG Z1 AX4U2400W8G16-QRZ | 15-15-15-30 (1T) | 12-12-12-24 (1T) | 11-11-11-22 (1T) |
Crucial 32GB DDR4-2133 CT4K8G4DFD8213 | N/A | 12-12-12-24 (1T) | 10-10-10-20 (1T) |
Every time we doubled the number of modules or the density of its ICs, we had to increase latency by one clock cycle to maintain stability. Four 8GB modules (Adata and Crucial) needed 12 cycles, eight 8GB modules (G.Skill) needed 13 cycles, and eight 16GB modules (Corsair’s 128GB kit) needed 14 cycles, to remain stable at DDR4-2400.
Rated at DDR4-2400, Corsair’s 128GB Vengeance LPX reaches DDR4-2600 without much difficulty. Testing at 1.0 BCLK strap might have been easier at these low data rates, but the previous 1.25x strap was maintained so that readers could compare previous reviews.
We could blame the density of the modules for the relatively low overclocking capability, but Asus instructs us that DDR4-2666 is roughly the maximum data rate currently achievable with any 128GB kit at moderate voltage settings, due to limitations of the CPUs memory controller. Given this limitation, we’re looking forward to improved timings rather than higher data rates on future generations of 128GB kit.