Upping CPUNB voltage and freq.

[madman7]

I'm playing with the CPUNB voltage and freq. on my OCed 980 BE. I have the freq. at 2600 and the voltage at 1.2625. Previuos settings were 2400 and 1.25v. I have ran Prime95 for 30 mins and so far it's stable. According to storm-chaser, this should increase memory bandwidth. If it runs stable for a while, I may try to go higher. Any thoughts? I've noticed that my temps are down about 1-2C at these present settings.

 

[ice445]

In my experience overclocking the CPU NB can be tricky, as even if it isn't stable you'll most likely pass blend without an issue. You have to burn with large FFT for 8 hours to ensure the stability of the IMC.

 

[madman7]

What normal everyday computing would show if there are issues upping the CPUNB? 8 hrs. seems a little extreme. I just ran the large FFT and 1 worker stopped are 15 mins.

 

[madman7]

I did some research and found this link:
http://www.homepcbuilder.com/overcl...ideos/lesson-06-cpu-nb-ht-link-overclock.html
My memory is set at 1333 so/2=666.5x3=2000. My NB freq is now at 2400 so it's pretty high. My memory will do 1600 but I've been told the Deneb core doesn't play well with 1600 memory. According to the link 1600/2=800x3=2400 so I'm running at 1600 memory speed. It also says the HT Link should be upped to the NB freq setting. Should I up the HT link to match the NB freq.?

 

[ice445]

No, HT link shouldn't be touched as it will just give you instability. And the Deneb IMC can handle 1600 in most cases. A 980 given how recent they are shouldn't have any issues. Just up CPU/NB volts (Not NB) to around 1.275. I actually have the same memory as you and I've found it can run at 1600 speeds at 1.5V instead of the spec voltage (1.65). Give it a try, I've heard it reduces the load on the IMC slightly.

 

[madman7]

When I first built this system, it wouldn't boot with the memory at 1600 and 1.50v. I had to bump the voltage to 1.66v to get it to post. When I went to overclock, I was told to turn the memory down to 1333 for stability. At 1600, I couldn't get stable at 4.1ghz. When I went 1333, it was stable so I left it there. I'm not sure where to set the timings at 1600.

 

[Neuromancer]

I did some research and found this link:
http://www.homepcbuilder.com/overcl...ideos/lesson-06-cpu-nb-ht-link-overclock.html
My memory is set at 1333 so/2=666.5x3=2000. My NB freq is now at 2400 so it's pretty high. My memory will do 1600 but I've been told the Deneb core doesn't play well with 1600 memory. According to the link 1600/2=800x3=2400 so I'm running at 1600 memory speed. It also says the HT Link should be upped to the NB freq setting. Should I up the HT link to match the NB freq.?

No not on deneb/thuban or any previous generation. HTLInk has more of an impact on bulldozer according to some studies I saw. HTlink is basically the BUS for the interface to the PCIE graphics card. I would leave it at 2000 and call it a day.

In my testing with an OCed 4890. Raising it WILL improve GPU performance, reducing it will lower. However raising it REDUCED CPU performance more significantly than it INCREASED GPU performance. Leave it at stock and call it a day.

your CPUNB 3x memory speed is accurate though that is straight from AMD themselves. More is always better of course, but not essential its not a HUGE differnce once a gain (once you pass 3 times)

As for mem dividers. I have heard that 1600 mem divider is also tuff to do on older chips. So it might be better to run 1333 mem divider, drop HTLink to 1600 and leave CPUNB at 200 and then just increase HTREF up to 240. This gets you 1600 MHz speed with the divider. However this is all moot at the multi issues was on c2 denebs I believe.

You shouldn't but might need a small NB voltage bump to hit 240HTREF. (NOT CPUNB) all depends on the setup.

Lastly adjust CPU multiplier to hit your current desired CPU frequency.

 

[madman7]

No, HT link shouldn't be touched as it will just give you instability. And the Deneb IMC can handle 1600 in most cases. A 980 given how recent they are shouldn't have any issues. Just up CPU/NB volts (Not NB) to around 1.275. I actually have the same memory as you and I've found it can run at 1600 speeds at 1.5V instead of the spec voltage (1.65). Give it a try, I've heard it reduces the load on the IMC slightly.

What are your timings at 1600. Did you set it at auto or manually enter the numbers? If you manually entered numbers, which and what values? At 1600, mine needs 1.65v(actually 1.66v) to get it to post.

 

[ice445]

What are your timings at 1600. Did you set it at auto or manually enter the numbers? If you manually entered numbers, which and what values? At 1600, mine needs 1.65v(actually 1.66v) to get it to post.

I used 9/9/9/24/1T at 1.5V, with two separate batches of the same memory you have. One of which I purchased way back at the release of DDR3 (When 4GB was $120). Also I entered manually.