DDR4 performance ranking official version: 3
DDR4 performance ranking official version: 3
I view anything slower than JEDEC standards—like DDR4-2133MHz/CL15 or lower—as sluggish. Anything needing a higher voltage (most kits list 1.35V for DDR4, while 3200/16 models usually say 1.35V or more) is considered moderately quick. If it pushes beyond the voltage limits recommended by Intel or AMD, I’d label it as "blazing."
Spoiler: The Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-5000 CL18 runs at 1.5V, which is above the Intel Comet Lake CPU’s max of 1.35V plus a 5% buffer (about 1.417V). This could mean it slows down to meet the voltage spec or needs a higher voltage than recommended. You might see it run slower or demand more power.
Note: The Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-5000 CL18 operates at 1.5V, surpassing Intel’s suggested limit of 1.35V + 5% (1.417V). This might force it to operate at a lower speed or require a higher voltage.
If your BIOS lacks tuning options like XMP, I’d rate it as average/acceptable/fair/reasonable/adequate depending on your needs. For my setup—say an i7-6700K with Z170 chipset—I’d prefer more RAM that’s slower rather than less.
Choice between 64GB DDR4-2133 CL15 or 32GB DDR4-4000 CL18? I’d pick the 64GB 2133 for better performance. Even 32GB of DDR4-5000 would likely be inferior to 64GB DDR4-2133, unless cost is a factor.
My sticks are DDR4-3066MHz / CL14 (9.1ns) which is above average, followed by DDR4-2666MHz / CL13 (9.7ns) as average. It might be worth calculating sub-timings too—adding 14, 17, and 17 gives 48, divided by 3 equals 16. Also, 13, 15, and 15 sum to 43, divided by 3 is about 14.3.
You were asking about voltage guidelines from CPU makers for their memory controllers and JEDEC standards for speeds that non-Z Intel boards or AMD support out of the box, without XMP or BIOS changes.
He mentions a CPU maker, but I recall Intel mentioning up to 1.50V. I don’t know the exact model. The details seem unhelpful without proof. It’s also unclear why memory controller and RAM voltages matter. I’ve never heard of a CPU failing because of higher memory voltage.
(Strictly B-Die...) 2.0v would be intense or high voltages. For memory modules, 1.60-1.650v should work as long as it stays cool. Under 50c is ideal. I experienced it myself—they overheat at ambient 1.90v, so below that’s best. I keep at 1.60v or less and have no problems. Vccio and Vccia sit at 1.20v. VTTDDR reads 0.8v (if I recall right). Fast! Usually at 4000mhz CL 16-16-16, I handle 1.410v or all 14s at 1.60v. The sticks are rated CL19-19-19 4267mhz and I really enjoy adjusting them.