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post #2 of (permalink) Old 02-06-2019, 05:23 PM
jfriend00
Memory Overclocker
 
Join Date: Nov 2018
Posts: 461
Rep: 20 (Unique: 9)
Quote: Originally Posted by Jaz11 View Post
Hi
I am working on a stable 24/7 memory clock. I bought a high end Trident Z 4000c17 17 17 37 2T kit (2x8gb). I had high expectations that i could either push frequency much higher or timings a good bit lower. So far not having a great deal of luck. I presume its samsung Bdie

Im using memtest86 version 8.1 boot from USB in bios which seems to be the most accurate and recommended way of finding errors. Memtest64 in windows does not. Aida 64 benchmark doesnt either.

Ive managed to get 4000mhz c16 16 16 37 2T no errors. i set Dram to 1.49v as im happy to run that daily. VCCCIO and VCCSA to 1.27v.

I can boot windows and run games and stress tests fine with 4133 c16 16 16 36 but memtest86 finds errors so doesnt seem like it would be a good daily clock.

I have tried pushing 4200mhz and over but cant seem to get a boot. even up to ridiculous timings eg 20 20 20 40 2T. Is this just the limit of my memory controller?

Any tips to help me get either higher frequency or lower timings?

Cpu: 9900k 5ghz all core
MB: Maximus XI formula
I have Samsung B-die TridentZ 2x8 sticks (XMP rated for [email protected]) on a ASRock Z390 Taichi with i7-9700k. I can do [email protected] with very tight secondary and tertiary timings at DRAMV 1.45V and VCCIO and VCCSA at 1.18V. I can do [email protected] at DRAMV 1.50V and VCCIO and VCCSA at 1.25V.

Both configurations are stable with RAMTest to 20,000% (which is an overnight memory test) and with PassMark's MemTest86 (booted from USB) for 8 passes, all tests, all CPUs (not running in parallel). It was definitely harder to get stability at 4133 than at 4000 and, in fact, my AIDA64 memory benchmark numbers are better at 4000 so that's where I'm running for 24/7. I could not find any configuration that would boot at 4200. I suspect it might run at 4200, but the motherboard doesn't train properly at 4200 to get things started (it has a hard time training at 4133 too). I may try again sometime with more manual settings (just for fun).

Going above the XMP rating on your sticks is just silicon lottery and your motherboard's ability to figure out secondary and tertiary timings that will work. Sometimes you can go way above what the sticks are rated at and sometimes only a bit higher - it all depends upon what sort of chips you got. With memory sticks, it only takes one memory chip out of all the ones on a stick that's holding things back to hold the whole set back. You can nearly always improve benchmark numbers by tightening secondary and tertiary timings, but that is a real time sink activity because you've got to run long stability tests over and over again to find how far you can go on each of the important timing numbers.

[email protected] (-1 AVX offset) on ASRock Z390 Taichi with Noctua NH-D15 air cooler
CPU offset voltage of -25mv, runs VRVout 1.240-1.313V on full AVX load, 1.225-1.275V on non-AVX load
2x8GB [email protected] at 1.45V, G.Skill F4-3733C17Q-32GTZKK (XMP rated [email protected])
EVGA GTX 1060 6GB OC with Corsair RMx 750W power supply
Samsung 970 EVO 500GB NVMe boot SSD and four other drives all in a Fractal Design R6 Case
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