AMD A-series northbridge clock

[Insert_Nickname]

I've just joined the APU owners club. Roaming around in the BIOS I found an item labled "northbridge clock". Obviously it controls the clock frequency of the northbridge, but what does it affect? I'm kind of curious, never having played that much with APU systems. My experience has been limited to pre-builds without too many BIOS options...

 

[ShintaiDK]

I assume it refers to the uncore part. L3, memory controller etc.

 

[Durvelle27]

It controls the memory controller

 

[Insert_Nickname]

I assume it refers to the uncore part. L3, memory controller etc.

My thinking too.

It controls the memory controller

So higher speed for faster memory and vice versa, or...?

 

[Warsam71]

Hi there
The northbridge is a chip that normally sits on the motherboard. Its purpose is to control/direct the "traffic" between the CPU and memory (RAM). By traffic I mean data that needs to be stored and/or accessed by the CPU (to perform a function/task) and other components when running programs, pretty much everything. The NB and CPU are on the same chip in our APUs - improving the performance, faster access to memory (data). You can overclock the NB to increase the number of tasks/functions, boosting the overall performance of your system. There are lots of posts, articles on "Overclocking the NB", just do a search I'm sure you'll find lots of info on this topic.

 

[Insert_Nickname]

Hi there
The northbridge is a chip that normally sits on the motherboard. Its purpose is to control/direct the "traffic" between the CPU and memory (RAM). By traffic I mean data that needs to be stored and/or accessed by the CPU (to perform a function/task) and other components when running programs, pretty much everything. The NB and CPU are on the same chip in our APUs - improving the performance, faster access to memory (data). You can overclock the NB to increase the number of tasks/functions, boosting the overall performance of your system. There are lots of posts, articles on "Overclocking the NB", just do a search I'm sure you'll find lots of info on this topic.

Thanks for the reply. But I do know what a northbridge is (been doing computers for 20+ years...). I also did google. But most of what came up refers to the AM3(+) platform that has a seperate northbridge chip, not the integrated one of the A-series.

The original question was what is affected by changing the northbridge clock. Memory controller?, PCIe controller?, "RadeonBus"? (I think its called, the interconnect between CPU and GPU) etc.

If you can provide some details, I'd be grateful...

 

[Warsam71]

Hello

On an APU the northbridge speed will be the L2 cache and integrated memory controller (both CPU and Radeon Memory Bus), they both run on the northbridge clock. PCIe speed and HyperTransport speed are managed separately in most BIOS's.

Increasing the NB block will have an effect on nearly all aspects of performance; any CPU core that needs data will get it faster because you've reduced the latency between the core and the memory (L2 or main system memory)

 

[Insert_Nickname]

Hello

On an APU the northbridge speed will be the L2 cache and integrated memory controller (both CPU and Radeon Memory Bus), they both run on the northbridge clock. PCIe speed and HyperTransport speed are managed separately in most BIOS's.

Increasing the NB block will have an effect on nearly all aspects of performance; any CPU core that needs data will get it faster because you've reduced the latency between the core and the memory (L2 or main system memory)

Thanks. That's very helpful info. :thumbsup:

I always like to know how the "nuts and bolts" actually function. Another thing I have noticed is that on most APU systems, the NIC is wired directly to the APUs miscellaneous PCIe lines, bypassing the southbridge. That's actually pretty clever... :sneaky: