Question RAM on an AM4 system - is the motherboard and/or QVL significant, or is it all up to the CPU's memory controller?


The subject line is pretty much my question.

I ask this because I have the following plan for my girlfriend, who will use this system primarily to work, though I plan to get her into some very light gaming.

  • Ryzen 5 5600G
  • Asus Prime B450M-A II motherboard (a BIOS exists to support
  • 2x8GB RAM
  • Corsair CX450 PSU
Her monitor is a 34" 2560x1080 with FreeSync in the range of 48-75Hz.

I was just going to go with 2x8GB of 3600MHz RAM, but, while I know the iGPU is a hair above the GT 1030 GDDR5 in performance (the card she has in her current system, R7 250E GDDR5, performs slightly below the GT 1030 GDDR5), I though that I might be able to squeeze a little extra out of the iGPU with faster RAM. The idea is to go as fast as I can with a 1:1 FCLK/memory ratio, and it seems that 2000MHz is readily possible based on the 5600G review.

That motherboard's RAM support QVL for the 5000/5000G series CPUs is here. It lists quite a number of RAM modules/kits at 4000Mhz and above.

Normally, I wouldn't pay much extra, but, there's a particular kit, the G.Skill Ripjaws V F4-4400C18D-16GVKC, that MicroCenter sells for $69.99 for the kit (and $3.50 off of that for using Micro Center's credit card). Unfortunately, that kit is NOT on the QVL list, though several other G.Skill 2x8GB kits at speeds of 4000, 4133, 4200, and 4266 are on that list.

I'm not looking to hit 4400MHz on the RAM... but, what are the odds that:
  • This RAM will work at all in that motherboard
  • AND that I can get it to run at 4000MHz, or, worst case, even 3800MHz?
If it takes loosening/lowering the timings, I'm fine with that. Just want to see if I can squeeze a little more out of the iGPU than the 3600MHz RAM would allow for.
The memory QVL documentation is simply what the manufacturer tested on the motherboard and said it was good. You can use any RAM you want as long as it meets the specs the motherboard laid out.

None of the RAM I've used was on a motherboard's QVL documentation and they all worked just fine.
Some limit is also imposed by BIOS. XMP is not "Exact science" just a suggestion to BIOS to use particular settings for best tested performance. XMP is also an Intel invention so BIOS for Ryzen system often has to improvise settings. It's best to have latest compatible BIOS.