It’s already been well established that AMD’s Ryzen CPUs love high frequency, low latency RAM modules. That’s because the speed of the system memory being used directly affects the speed of Infinity Fabric (IF), AMD’s high-speed interconnect between CPU core clusters, chiplets, GPU cores (in case of APUs) and memory.

According to AMD, the optimum performance is attained when IF and DRAM frequency is in the ratio of 1:1. For example, if you are running 3200MHz DDR4 RAM, the DRAM frequency will be around 1600MHz (since DDR = Double Data Rate) and in turn, the IF frequency(FCLK) must also be 1600MHz. However, it has come to the notice of some users that the majority of motherboard BIOSes fail to auto-alter the speed of IF corresponding to the set frequency of DRAM and in turn lessens the performance gains. So if you want to extract that additional juice of performance, this little tweak in BIOS settings should be very handy.

Popular YouTuber JayzTwoCents recently noticed the same issue in his 3900x video and upon applying the changes, gained significant performance across all CPU dependent workloads.

Memory Frequency is double of DRAM frequency, as explained earlier. So for the 1:1 ratio, FCLK has been set to half of the Memory frequency.
DOCP =ASUS’ AMD equivalent of Intel XMP.
DOCP Only = only Mem OC; DOCP + IF OC = Mem OC + FCLK OC

In the next few images, we look at the improvement in performance across a few applications between DOCP only and DOCP + IF OC.

+0.7% vs +1.3%, ie, approx 2x additional gain.
+0.1% vs +1.3%, ie, 13x additional gain.
+7.8% vs +10%, ie, approx 28% additional gain.
Avg FPS 124 vs 135, ie, approx 9% additional gain.
Min FPS 98 vs 109, ie, approx 11.5% additional gain.

So, there you have it. Quite impressive considering that you are getting around 10% extra performance without even overclocking your CPU core.

Read more:

Leave a Reply