DDR4 do not reach native frequency in ASRock Fatal

Hello guys.

I am facing a problem with my DDR and would like your help in solving it.

I bought 32GB of RAM, 4 x 8GB, G.Skill Trident Z RGB 4266mhz (F4-4266C19D-16GTZR). But I can not get them on the native frequency. I got a maximum of 3866mhz, with 2-DIMM (16GB) and f 4-DIMM.

I'm using a 8700k at 4.8mhz, with cache at 4450mhz and BCLK at 103,250. CPU Vcore is at 1.23v.

My mobo is an ASRock Fatality Gaming Professional. I saw videos on youtube and reports in forums that the guys are getting good overs in RAM with this model and in Taichi.

ASRock reports up to 4333mhz of frequency supported on its QVL, including a model exactly like mine (F4-4266C19D-16GTZR).

In the memories I got to set 1.5v, I raised the VCCIO to 1.4v and VCCSA to 1.45v, but I did not succeed.

My BIOS is upgraded to P1.70

I would like your help for an eventual solution that I have not yet taken.

Thank you .

I'm in the same boat (tridentz 4266 19-19-19-39 kit) but I'm not complaining because I understand the risks of overclocking. I can get 4000MHz RAM running fine, boots every time. Anything higher than that has an extremely low chance of POSTing, but if it does POST, it POST's every time after that. But I'm heavily into changing RAM timings too, so if I use a RAM timing that is bad, it'll fail RAM training and I'm back to square one of trying to get the RAM to post at a speed higher than 4000MHz.

Maybe you should concentrate more on modifying timings at the highest possible speed. After all, it's still a great kit. While I can't get 4266 working reliable, I have 4000 working at CAS16 at a reasonable 1.5v. Also, most of my RAM speed improvements come from an aggressive tRFC and tREFI, as well as minimizing all tRDRD, tRDWR, tWRRD, and tWRWR timings, especially tWRWR timings. The auto timings of tWRWR are very loose, and minimizing those timigns hugely increases the speed of sequential writes. I gained 50% write speeds minimizing my tWRWR timings (41GB/sec -> 60GB/sec)

Try a speed that you knows works good for you and just decrease voltage of VCCIO until it no longer POSTS, then bring it back to the previous voltage. Do the same for VCCSA. Then you'll have an idea of what to run at. If you want to try higher speeds then, work from there. Immediately injecting 1.4v to both rails is not good (unless you just want to get the system to POST at all, then start dropping voltages if you do get a success). Working on RAM takes a long time since stability testing can take a logn time, especially if a timing you are working on throws very rare random errors