Overclocking is never guaranteed so the presented results may vary from results on other memory kits. I am not recommending overclocking if you do not know what are you doing. High voltages may damage hardware and it will not be covered by warranty.
You have to remember that tested Patriot Viper 4 memory is not a quad channel kit and it wasn’t designed for the Intel X299 chipset. It doesn’t change fact that there are no issues with stability and overclocking.
I was able to set DDR4-4000 CL17-17-17 1.35V on ASRock X299 Taichi XE and DDR4-4100 CL18-20-20 1.35V on ASUS X299 TUF Mark 2. Performance on ASRock motherboard is better and also it’s easier to set DDR4-4000. The Taichi XE is a new motherboard so I assume that results will be better when new BIOS will be released.
Both results are great and there is nothing to complain about. I was even surprised how easily Patriot Viper 4 DDR4-3733 was able to reach DDR4-4000 mark on both motherboards. It wasn’t possible on couple of other memory kits based on the same Samsung IC.
I have to add that overclocking results were made on safe voltages. Higher voltage is not really helping to improve memory frequency as it’s limited by the used platform. We can tighten the timings what will help to lower latency but it’s also not so big performance gain.
One more difference between overclocking on ASUS and ASRock motherboard is that ASUS requires additional settings to pass DDR4-3866. I mean manual training settings which you can find on the bottom of the timings list. Some other settings may also help to keep stability.
ASRock Taichi XE somehow didn’t need above settings and motherboard seems a bit more user-friendly, especially when you are not advanced in memory overclocking.
Patriot Viper 4 DDR4-3733 for sure has high overclocking potential and I assume that DDR4-4200+ is possible using Kaby Lake or Coffee Lake platform. Skylake-X is harder to overclock but memory runs in quad channel mode so its performance is much higher.
The Viper 4 DDR4-3733 memory is offering impressing performance and I think that all who are looking for fast DDR4 memory will be satisfied regardless if memory will be overclocked or not.