PCI-Express clock rate: please help?
Moderator: General Discussion Moderators
- Slink
Not to be a dick, but...
- Posts: 1904
- Joined: Mon Aug 16, 2004 04:42 am
- Location: Niagara County, NY
PCI-Express clock rate: please help?
So, the first two links in this Google search lead to excellent helpful forum discussions, but I really must ask, WHY does my mobo BIOS give me the option to overclock my PCI-Express bus to 200 Mhz?? (The default is 100 Mhz.)
FROM GOOGLE.
All PCI Express slots use a 100 MHz reference clock to generate its clocking signals. This is where the PCI Express Clock BIOS option comes in. It controls the frequency of the PCI Express reference clock.
By default, the PCI Express Clock is set to 100 MHz. This is the official reference clock speed for the PCI Express interface. Some BIOSes allow you to adjust this reference clock, usually in steps of 1 MHz.
Adjusting the PCI Express reference clock changes its signalling rate and bandwidth. However, because the PCI Express x16 interface already has such high bandwidth, overclocking it would only have a small effect on real world performance.
In motherboards that suffer from the PCI Express x1 bug, adjusting the reference clock speed up or down can potentially "trick" the motherboard to restore the PCI Express slot to its full x16 mode. However, raising the PCI Express reference clock to 120 MHz can cause timing-sensitive PCI Express devices like SATA controllers to fail. Therefore, it is recommended that you do not exceed 115 MHz
All PCI Express slots use a 100 MHz reference clock to generate its clocking signals. This is where the PCI Express Clock BIOS option comes in. It controls the frequency of the PCI Express reference clock.
By default, the PCI Express Clock is set to 100 MHz. This is the official reference clock speed for the PCI Express interface. Some BIOSes allow you to adjust this reference clock, usually in steps of 1 MHz.
Adjusting the PCI Express reference clock changes its signalling rate and bandwidth. However, because the PCI Express x16 interface already has such high bandwidth, overclocking it would only have a small effect on real world performance.
In motherboards that suffer from the PCI Express x1 bug, adjusting the reference clock speed up or down can potentially "trick" the motherboard to restore the PCI Express slot to its full x16 mode. However, raising the PCI Express reference clock to 120 MHz can cause timing-sensitive PCI Express devices like SATA controllers to fail. Therefore, it is recommended that you do not exceed 115 MHz