Asus Maximums z790 Hero > XMP

[RickJamesBish]

I have an Asus Maximus z790 Hero with an Intel i7 13700k with 

G.Skill Trident Z5 RGB Series (Intel XMP 3.0) DDR5 RAM 64GB (2x32) 6800 MT/s CL34-45-45-108 1.40v in  DIMM A2 / B2 as per the manual.

My system runs stable until I enable XMP.  I have never used this before so all I did was clicked enable and it appeared to load the correct settings. Game crashes within minutes of playing. Disable that option and game for hours with no issues.
Is there a trick to getting the most out of Ram with XMP? 

[Silent_Scone · Accepted solution]

Hi @RickJamesBish 

The crashing is due to an unstable overclock. XMP is classified as overclocking due to running the system outside of specification. 

Contrary to assumptions, XMP/EXPO doesn't ensure automatic overclocking. Tighter timings or higher frequencies may require manual adjustments for stability. Overclocking cannot be assured due to variance between parts when run outside manufacture specifications. XMP/EXPO success also greatly depends on the processor's Integrated Memory Controller (IMC) capabilities. More here

You can try XMP II. This is the default DIMM profile from the memory vendor and contains sub-timings stored within the SPD EEPROM of the memory module. 

Did you check to see if the kit is on the Memory QVL for the Hero? For better success in achieving "plug and play" overclocking, consider memory kits that are one to three frequency bins below the motherboard's maximum qualification on the QVL for the density you wish to run. The higher the frequency and tighter the timings, the more likely manual tuning might be needed to adjust for signal variance between parts. Success with memory kits at or near the top of the QVL validation table depends largely on the quality of the CPU memory controller.

[RickJamesBish]

Thanks. The memory modules are listed in the chart as compatible. I enabled XMP and chose XMP II. It did not crash but I noticed that in HWiNFO 64, it shows DDR5-6800 but says 3400.0 MHz (DDR5-6800 / PC-54400). Maybe I am interpreting incorrectly but it sounds like its running at 3400.

[Silent_Scone]

Just a quick clarification, HWiNFO doesn't show the DRAM frequency at "half speed." It displays the actual memory clock (e.g., 3400 MHz), and since DDR (Double Data Rate) RAM transfers data on both the rising and falling edges of the clock, the effective speed is double that.

3400 MHz clock = 6800 MT/s effective data rate.

[Nate152 · Accepted solution]

Hello RickJamesBish

HWinfo shows the Dram frequency in half.

3400MHz = 6800MHz