Why do anandtech never OC the northbridge on AMD CPUs?

[Meaker10]

In the tests the NB frequency is never discussed. It has such a massive performance impact, especially in games but it gets completely forgotten.

 

[kowalabearhugs]

I wouldn't say they never discuss it... http://www.anandtech.com/show/3877/...investigation-of-thuban-performance-scaling/7

 

[Meaker10]

Yeah and then they disregard those results and simply just seem to stare at the poor ocing scaling when they look at the phenom II 980 *facepalm*

 

[busydude]

AT is not the only tech site to not OC NB, almost all major review sites do not OC too. There must be a reason.. for all them to not OC NB.

 

[mrcmtl]

maybe because 90% of the people who buy Phenoms don't end up OCing the NB?

Although it would have been nice to have a Phenom with the NB OCed just to compare.

 

[richierich1212]

yeah it's pretty sad

 

[drizek]

When I tried OCing my NB on my X3 720, even a tiniest increase prevented my system from POSTing, requiring a full power down, unplug, wait, plug in, push the button, reset the bios, etc. restart.

Not sure if it is (gigabyte) motherboard or CPU related, but I think this might have something to do with why they don't OC it.

 

[(sic)Klown12]

AT is not the only tech site to not OC NB, almost all major review sites do not OC too. There must be a reason.. for all them to not OC NB.

More work for the reviewers and takes additional time. Most of them want to get the review out as soon as possible and need most of the time for benchmarks.

It would be nice if they can do a follow up article afterwards though, but I don't think they will since I don't see AMD reviews having a lot of page views and therefor not bringing in much income.

 

[richierich1212]

When I tried OCing my NB on my X3 720, even a tiniest increase prevented my system from POSTing, requiring a full power down, unplug, wait, plug in, push the button, reset the bios, etc. restart.

Not sure if it is (gigabyte) motherboard or CPU related, but I think this might have something to do with why they don't OC it.

That's because you need to increase CPU-NB Voltage and/or NB Voltage.

 

[tvdang7]

wow i did not even know it made that much of a difference in performance!! Very good to know now.

 

[StrangerGuy]

Yeah and then they disregard those results and simply just seem to stare at the poor ocing scaling when they look at the phenom II 980 *facepalm*

As if people would spend on a $185 AMD quad with almost no room for OC with lousy power consumption compared to a $220 2500K. Who cares about NB-OC at that price range when Intel (shockingly) has the better bang for the buck?

 

[Obsoleet]

95% of tech sites have no integrity, they're all taking handouts of some sort. I know people who run software review sites and they refuse to review hardware to maintain the site's integrity.
I enjoy AT and HardOCP and others. It's just the truth. Cutting to the chase on your question.

 

[drizek]

That's because you need to increase CPU-NB Voltage and/or NB Voltage.

My Gigabyte board doesn't have an option for CPU-NB voltage, only NB voltage.

 

[cusideabelincoln]

As if people would spend on a $185 AMD quad with almost no room for OC with lousy power consumption compared to a $220 2500K. Who cares about NB-OC at that price range when Intel (shockingly) has the better bang for the buck?

Phenom IIs have been out for a long time and have offered pretty good bang for the buck the majority of that time.

 

[kowalabearhugs]

Is NB overclocking totally dependent on motherboard quality+cooling or can the cpu itself somehow hinder NB potential?

edit* Assume unlocked processor and a stable core speed.

 

[(sic)Klown12]

Is NB overclocking totally dependent on motherboard quality+cooling or can the cpu itself somehow hinder NB potential?

edit* Assume unlocked processor and a stable core speed.

The NB being talked about here is actually the integrated memory controller and L3 cache(both located on the CPU itself). The speeds these can reach should be independent of the motherboard being used, as long as the motherboard can handle the additional power usage(use a low quality mobo and you will blow up a VRM).

 

[sm625]

You only get 1% performance boost for every 10% you overclock the NB. In some cases, like for SC2, you get 2% performance boost for every 10% you overclock the NB. Oh boy... And like a previous poster mentioned, I also get no POST when I OC the NB by 10%, even if I raise its voltage by +0.1. I'm sorry but I'm not going to +0.2V just to get a 10% OC. It may actually work, but it seems so unworth it. I have a gigabyte GA-690GM-S2H AM2+ board with an X2 240 clocked at 3.4GHz. I am happy with the board since it is 4 years old and still running like a champ, with a cheap cpu upgrade and a bios that can actually be flashed.

 

[fffblackmage]

I tried overclocking the CPU-NB on my Phenom II from 2GHz to 2.4GHz. I ran some benchmarks (RE5, LP2, STALKER:COP, FC2), but only ended up with a .03% average increase in framerates. So now, I don't even bother overclocking anything on my Phenom II.

 

[Lepton87]

You only get 1% performance boost for every 10% you overclock the NB. In some cases, like for SC2, you get 2% performance boost for every 10% you overclock the NB. .

How did you calculate that? What I see is that over-clocking NB frequency by 40% yielded 16% improvement in fps.(StartCraft2)

 

[sm625]

2%, 4%, meh, its all pretty much the same.

 

[dorion]

Some boards can't handle NB overclocks, my old gigabyte board would require a bios reset whenever I tried to OC the NB, now on my new board I'm running the NB at 3GHz for shits and giggles.

I also believe it helps me keep things more stable, I can't run my processor or memory at the voltages and speeds I have now without OC my NB to at least 2.6GHz.

 

[Skurge]

2%, 4%, meh, its all pretty much the same.

There isnt much point just overclocking the NB only. Its an added performance increase to the CPU overclock you have. If you have your CPU already clocked as high as it can go, why turn down an extra 5-15% performance increase?

 

[richierich1212]

NB overclocking isn't just for gaming. It helps with program load times and boot times. You'll see a difference in everyday tasks.

 

[repoman0]

NB overclocking isn't just for gaming. It helps with program load times and boot times. You'll see a difference in everyday tasks.

I don't buy that.. program loading and boot times are completely hard drive limited. We're talking 10ms access times for a platter hard drive and less than 100MB/s sequential, and maybe .01ms / 200MB/s for an SSD - versus the processor, which goes through a couple million clock cycles in 1ms. Same with the northbridge, overclocked or not - so next to zero latency and bandwidth measured in 10s of GB/s..

That said I keep my CPU/NB at 2.6GHz just because.

 

[BD231]

I oc the piss out of anything if I can, the northbrdige, plenty of performance to be had by going from 200 to 240-250. It's noticeable on the desktop and pretty much any 3D application I use, so, I do it.