RAM DDR3 VS DDR4 1080P

So does anyone know WHY the CAS latency is so much higher on DDR4? Why don't we have DDR4 2133MHz CL7 kits when we had DDR3 2133MHz C7 kits? I can only guess it's because of the lower power?Д¬PU:i7-2600K 4751MHz 1.44V (software) -> 1.47V at the back of the socket Motherboard: Asrock Z77 Extreme4 (BCLK: 103.3MHz) CPU Cooler: Noctua NH-D15 RAM: Adata XPG 2x8GB DDR3 (XMP: 2133MHz 10-11-11-30 CR2, custom: 2203MHz 10-11-10-26 CR1 tRFC:230 tREFI:14000) GPU:В Asus GTX 1070 Dual (Super JetstreamВ vbios, +70(2025-2088MHz)/+400(8.8Gbps)) SSD: Samsung 840 Pro 256GB (main boot drive), Transcend SSD370 128GB PSU: Seasonic X-660 80+ Gold Case:В Antec P110 Silent, 5 intakes 1В exhaust Monitor: AOC G2460PF 1080p 144Hz (150Hz max w/ DP, 121Hz max w/ HDMI) TN panel Keyboard: Logitech G610 Orion (Cherry MX Blue) with SteelSeries Apex M260 keycaps Mouse: BenQ Zowie FK1 It seems the only real advantage to DDR4 is the lower power draw. It wasn't a cheap kit, either, and it's handily beaten by both the DDR3 2200MHz CL7 kit and the 2133MHz CL7 kit in first word, fourth word, and eight word, and both of those kits were similarly priced to my kit. I've also included my own kit at the bottom, 3200MHz CL14. The chart below demonstrates what I'm saying.

The only place DDR4 is able to claim a victory is with the 4600MHz CL18 kit and the 4800MHz CL 19 kit, but even then it only wins on the eight word transfer, and one can argue that the first word transfer is the most important because the words are sent in critical word first order which allows the CPU to begin work immediately using that first word.

Basically, DDR3 2200MHZ CL7 is still the best overall RAM given that it's able to transfer the first word to the CPU in 7.82ns, the fourth word in 7.73ns, and the eight word in 9.55s. So it's been almost 5 years since the launch of DDR4 and I'm kind of surprised that we still don't have great CAS latency on most kits.

Ram ddr3 vs ddr4