I just ordered a barebones Minisforum UM690S and am currently trying to find some RAM-chips and an SSD to put in it, but apparently these RAM-chips were a bit more complicated than I had imagined.

It runs an AMD Ryzen 9 6900HX, which on its site says it supports DDR5-RAM up to 4800 MHz. On the Minisforum spec page, it also says that it uses the SODIMM form factor.

So my questions:

  1. Am I bound to 4800 MHz? Could I go for 5600 MHz and accept that I won’t get to utilize the full power? Minisforum sales rep says I should get 4800 MHz, but I’ve also read that higher is OK, it is just wasted. In my case, I can get 5600 MHz cheaper.
  2. The sales rep also specifically stated CL40. I can’t see that elsewhere, neither on the AMD-site nor Minisforums spec page. From my preferred retailer, I can either get 4800 MHz with CL38, or 5600 MHz with CL40. But not the stated combo of 4800 MHz and CL40. What are my choices here?

The specific chips I am considering are the Kingston FURY Impact-chips:

  • Kingston FURY Impact DDR5 4800MHz 32GB, CL38 (38-38-38)
  • Kingston FURY Impact DDR5 5600MHz 32GB , CL40

I am lost 🫠

  • @hperrin
    7•1 year ago

    Get whichever of those two is cheaper, because they both will work. The rated specs are the maximum/minimum. 5600MHz sticks will run at 4800MHz just fine. And CL38 sticks will run at CL40 just fine.

    After selecting their XMP profiles in the BIOS, you can either try booting and see if it’s stable at their max speeds, or lower the corresponding thing to the max the CPU says is ok.

    Btw, if it’s not stable at all at max speeds, and you can’t get back into BIOS, just reboot it like 5 or 6 times and the BIOS should reset.