AMD: Overclocking CPU bus speed could impact SATA equipment?
AMD: Overclocking CPU bus speed could impact SATA equipment?
Hello everyone,
I’m thinking about boosting the "CPU Bus" standard frequency on my AMD 890FX board from 200 MHz to a higher setting. I’ve heard that doing so could cause HDD issues because of faster SATA speeds, but others mentioned that SATA devices are linked to the PCIe Bus and can be adjusted separately from the default 100 MHz.
It seems most sources focus on "FSB overclocking" in relation to SATA and drive problems, which feels outdated for this situation. Since I can change the SATA speed in another BIOS section to 3 or 6 GHz, it looks like the CPU Bus frequency likely won’t affect those settings.
Could this adjustment be risky, even on a relatively new board or chipset?
In fact, the MB contains two Jmicron (SATA2) controllers which also run a PCIe bus and are influenced by FSB frequency; stabilizing them is simple by setting the PCIe frequency to manual at 100MHz. The other SATA (SATA3) devices are managed differently, as their FSB settings do not impact them. You can observe these details clearly in the manual's block diagram.
First of all, the speed is measured in Gigabits per second, not Gigahertz. As you mentioned, this has nothing to do with the CPU. HOWEVER, overclocking the CPU bus does influence other components. It's a straightforward idea—all computer parts are built to function together using the CPU bus frequency as a shared reference. Yet each component can operate at its own speed by a different factor (such as the CPU). For instance, a 3GHz CPU on a 200MHz bus would have a 15x multiplier. (15x200 equals 3000MHz = 3GHz). When you overclock, it's usually best to follow the multiplier, since it only impacts the specific part you're adjusting. Changing the bus frequency then affects all other multipliers, making it difficult to pinpoint overclocking issues or failures, as they could randomly impact any component. It's not considered "dangerous" like fire or explosions, but it should only be done with full confidence in your actions.
In fact, on that MB there are two SATA controllers, one using Jmicron (SATA2) which supports PCIe bus and is influenced by FSB frequency; stabilizing it is simple by setting the PCIe frequency to manual at 100MHz. The other SATA (SATA3) devices are managed differently, as their FSB remains unaffected. You can observe these details clearly in the manual's block diagram.