3 ms·
This is because Ryzen's "infinity fabric" or internal interconnect between the cores is tied to the RAM speed. This is kind of like the old days when CPUs used
by seabrookmx 9y ago
This is because Ryzen's "infinity fabric" or internal interconnect between the cores is tied to the RAM speed.
This is kind of like the old days when CPUs used a Front-side Bus (FSB). If you increased the FSB frequency it would increase the CPU frequency, the RAM frequency, and even PCIe depending on how it was wired up. It made things simpler to have the FSB be the sole clock-generator.
So despite the increased bandwidth moving from 2600 to 3200mhz RAM not having much impact on performance (in most applications), the increased frequency of the bus between the cores allows for greater performance beyond that.
IIRC Intel uses a ring-style bus with it's own clock, hence why it this effect only applies to AMD.
- floatboth 9y agoYeah, up until 3200 MT/s the IF has a lot of impact. > the old days when CPUs used a Front-side Bus (FSB) They still kinda do. It's not the bus, but there is one clock called BCLK (base clock) now and almost everything is derived from it. It's not adjustable on cheaper boards, but with a good board you can absolutely do the same adjustment :)
- seabrookmx 9y agoYeah I have an older box running an i7-920 which is overclocked from 2.6 to 3.6ghz with the base clock. Sandy Bridge and newer get extremely unstable when you toy with the base clock more than a few MHz though. You're basically stuck shelling out an extra few bucks for a "K" chip if you want to overclock on Intel now.
- floatboth 9y agoSkylake and newer have fixed this, they decoupled PCIe and stuff from BCLK. On Skylake you can actually do non-K (I ran a 6400 at up to 4.7GHz): https://overclocking.guide/category/intel-oc-guides/skylake-non-k-oc/ https://overclocking.guide/category/intel-oc-guides/skylake-... Of course on Kaby and later they closed the loophole...