I recently upgraded my CPU from an R5 3600 to an R7 5700X, keeping the same 16GB DDR4 RAM and other components. I enabled the same XMP profile, but I noticed something strange: Memtest showed my memory bandwidth jump from 19.5 GB/s to 42.8 GB/s! I'm not complaining, just curious about why this happened and what benefits it might offer, especially in terms of gaming performance.
5 Answers
Given the variation in memory chips, you could be benefiting from a better chip layout on your new CPU. Sometimes the silicon lottery gives you components that perform better than expected!
It sounds like your new CPU might be handling RAM settings better than your old one. Can you check the specifics on your RAM kit like its speed and primary timings? Sometimes, without realizing it, the older CPU runs at a slower memory setting compared to the newer one. A lot of Ryzen CPUs also perform differently based on the memory frequency and settings, so that could be a factor here!
That makes sense! Ryzen CPUs often max out between 1600-2000 FCLK, which is below the standard for DDR4, so it's likely your old setup wasn't utilizing the RAM optimally.
The hardware is actually similar between the Ryzen 3000 and 5000 series, so it could be due to a BIOS misconfiguration. Sometimes resetting the BIOS or enabling XMP correctly can reveal hidden performance. Have you tried checking all your settings since the upgrade? You could have inadvertently fixed an issue by just swapping CPUs!
I actually reset the CMOS when swapping CPUs, which might have helped get a better score out of my RAM too!
Make sure you set the RAM to the correct gear. I accidentally had mine set wrong after an upgrade and that limited performance significantly.
Keep in mind that modern DDR4 RAM operates with a 64-bit bus and uses a double data rate, so memory bandwidth can impact performance significantly. If you're on dual-channel mode, make sure your speeds are configured properly!
There's a specific limitation on the original Ryzen CPUs that caused lower memory performance in benchmarks. Your actual speed may not have doubled, but your results definitely have due to how memory was previously configured.
I have Crucial Ballistics Sport LT with an XMP of 1600 MHz. My operating FCLK was also at 1600 on both CPUs, so I can relate!