How important is OCing the NB frequency?

[jaylim0512]

So I overclocked my AMD Phenom II X4 955 BE to 3.9 Ghz

These are my current stats:

CPU voltage: 1.461 V
CPU/NB: 1.1 V
NB Freq=2000 Mhz
dram freq: 1067 mhz
dram voltage: 1.5 V

So my question is, would raising the NB frequency increase performance? And if I do decide to raise the NB freq, would I have to OC my dram speeds and the voltage and the voltage of the CPU/NB?

 

[razaice]

From what I understand, which isn't a whole lot, raising the cpu/nb frequency helps the computer take better advantage of your cpu overclock. Apparently, the cpu/nb is actually your processors memory controller. If you raise it, you won't have to oc your dram, but you may have to raise the cpu/nb voltage. You may not have to though. My cpu/nb frequency is 2400 and I was able to actually lower my voltage from stock to 1.0875. You can test it for stability the same way you did for overclocking the processor.

 

[Accord99]

Some relevant info:

http://www.anandtech.com/show/3877/...investigation-of-thuban-performance-scaling/7

 

[mrcmtl]

Raising your CPU/NB frequency helps to increase your overall performance. I think you have DDR3-1066 memory so raising your CPU/NB won't help that much as if you had DDR3-1600 for example. But you can still safely increase your CPU/NB to 2400Mhz with 1.2V on the CPU/NB.

 

[formulav8]

Since you have a PhII then you have both the Level 3 Cache and Memory Controller reside on the northbridge. In other words, the speed set by the northbridge, is the speed of the L3 cache and Memory Controller.

In my personal testing with a unlocked Sempron II (No L3 cache) memory latency decreased by 6% with about a 600/700mhz (Can't remember exactly) increase in northbridge frequency. Performance increase was only 2% in some things like SuperPI. But in OpenGL/Gaming/7Zip increases were up to 10%+.

Since you have L3 cache your performance should increase alittle more than a cacheless northbridge. But you may not be able to raise the clockspeed as high as a cacheless northbridge. Performance gains depend on what your doing.

 

[busydude]

I would definitely OC the NB.. mine is sitting at 2.6 GHz at 1.3V.. and it helps a lot for gaming, not so much for daily use though.

EDIT: Is your C2 or C3 stepping?

 

[tweakboy]

If you want to OC the FSB instead of multiplier you need to up the NB voltage, or higher vcore until you find sweet spot. Which may take a while and a lot of crashes etc lol gl, thx

 

[SickBeast]

There's an optimum speed for the NB. On mine it's 2400mhz. 2700mhz would work, but it was unstable and required too much voltage. If you're lucky you should be able to get ~2600mhz, perhaps even more.

Mine's a C3 stepping Phenom II 905e if that helps. I run it at 3.75ghz.

As others have said, overclocking the northbridge makes a huge difference in gaming, particularly in games like Starcraft.

 

[richierich1212]

Youll notice faster windows boot up times, program load times and slightly higher fps. It's a necessity for AMD CPUs. 2.6GHz should be easy.