Question 128G DDR5 3600Mhz Ram

[Victory Pete]

I bought a Dell XPS 8950 and was surprised to see it came with the slower 3600Mhz Ram. 64G and 32G come with 4400Mhz. Why is this?

 

[mdd1963]

I rather doubt any versions of XMP options for Dells are going to have any settings to accommodate all that far above 3600 MHz, especially with 4 RAM sticks; regardless of what alleged speeds of RAM (4800/5600/6200, etc) are installed, the BIOS selects what access speeds are chosen.

 

[Bob.B]

Right, but if the 128G was 4400Mhz I bet it would be a different story.

Dell has their reason why they down clocked the ram.
It may be as simple as with all 4 slots in use that was the max ram speed that was reliable.

 

[Karadjgne]

In that bios screen, Dell shows Memory Reference Clock : 133, everyone else (aftermarket) will use 200/266, which is essentially the same base. What you might be able to change is the Memory Ratio. It's on Auto. My guess is that ratio is currently 27, which multiplied by 133, will give you 3600. If you change that to 30 (or 15, depending on if they are going by data rate or dual data rate) that'll give you 4000. You'll most likely need to also raise the Memory Voltage to 1.1v from default.

If that works, you can keep bumping the ratio up, until it hits 4800 (ratio 36) and bump voltage up to 1.2v±