timtom33

I think thats a very good summary, thanks for explaining all of that. The last point you make is key, stability has to be number 1, i have been having crashes for a long time and it's because my ram has been unstable ever since i installed windows about 6 months ago and swtiched on the XMP profile. Everything i have since installed has probably had some errors baked in due to the ram instability. As you say, thats really incidious to the system and litters everything with errors and these build up more and more over time. Tomorrow i am taking off all ram overclocks and installing windows and all drivers again from scratch and then only using the 3600Mhz profile thats passed a full memtest, (or only use other profiles i have proved are 100% stable in memtest). I think i just took XMP as a gaurentee and when i saw 4000Mhz displayed in windows assumed that would be stable and never thought to test it. My mother board is not anything super high end, because i am using mATX and there are only a small choice in this space. Definately very ambitious of me buying such high frequencey ram even though i saw the motherboard spec saying it could suppprt up to 4133, but when you look at the QVL list they only have 1 set of ram listed as tested at that speed! Probably just to be able to market the board as "speeds up to 4133Mhz". I will be happy if i can push the timings down very low on 3600Mhz, as you have said, real world performance is not massive when going up to the super high frequencies. I have seen lots of charts saying ram speed is more or less irrelevant when gaming at 4k as its all VRAM on the GPU at that res.

Hi, thanks for the helpful reply. I appreciate it. I suspect you might be right. Seems my ram is not on the QVL list for the motherboard either, and not many even are on the list once you get over 3600Mhz. There are only 5 on the list for 4000Mhz and only 1 for 4133Mhz! I will try the suggestion about increasing the DRAM voltage and see if that works. I am not sure if i want to run over 1.35v 24/7 so I may just have to live to 3600Mhz and try and go for tighter timings. I tested 3600Mhz 16-18-18-36 last night and that passed memtest86! As you said i guess XMP is not a guarentee as there are lots of other factors at play which ram manufactures cant possibily account for. Just out of curiosity, why does the mother board have such a large effect on ram stability? CPU i can understand...

Hi, My system has been a bit unstable so i decided to perform memtest to see if the issue was ram related. I have since discovered than my ram is not stable when set to XMP Profile 1 - which is dissapointing. I have since run memtest for 8 passes (12 hours of testing) with no XMP profile selected at the standard 2133Mhz and it passes no problem. Can some tell me if there are some additional settings i need to change to get the ram stable? My understanding was the XMP Profile was meant to mean it would be stable on that profile and change all the settings needed for you? I have tried increasing VCCIO to 1.25v and System Agent Voltage to 1.3v and this didn't fix it. By the way - I have no CPU overclock and my cooling is average with temps hitting 80c when gaming. So i dont want to OC the CPU at the moment. ***Any help on how to get the ram stable at 4000Mhz on XMP Profile 1 would be greatly appreciated?*** PC Spec below: CPU: Intel i9 9900K GPU: nVidia 2080Ti Founders Edition RAM: Corsair Vengeance RGB PRO DDR4 32GB 4000MHz CL19 CMW32GX4M4K4000C19 Motherboard: Gigabyte Z390 M GAMING Storage: Samsung 970 PRO M.2 1TB + 860 PRO SSD 4TB