CPU OC vs Cache Ratio OC

[wyliec2]

I'm overclocking a 5960x on air (Noctua D15) and I'm at a 4.2 stable with 1.22v VCORE, 1.85v CPU input voltage and good temps.

How important is CPU Cache Ratio - leaving it on AUTO results in Aida64 clocks of CPU 4199 and Cache Ratio 2999 (stock).

Any attempt to raise Cache Ratio - say to 3.5 results in instability - even bumping voltages and load line calibration.

I have worked on this for hours and I'm tempted to just leave it as-is. Searches on the topic have found mostly questions and few definitive answers.

Thanks in advance for any input!

 

[Alex Dorades]

Balance CPU and cache ratio until you get max temp (80c) . Or leave cache as it is and rise CPU and if there is room some temperatures rise cache to reach the max temp.

 

[wyliec2]

Balance CPU and cache ratio until you get max temp (80c) . Or leave cache as it is and rise CPU and if there is room some temperatures rise cache to reach the max temp.

Seems no matter what I do, I can't budge the cache ratio without getting instability - bumping VCCIN up to 1.95v, adding adaptive cache voltage, etc. and I can't even run a 3.5 cache ratio. Everything runs fine with CPU frequency at 4.2 and cache at 3.0 - how much does this compromise the gains with CPU overclock?? Does leaving it at 3.0 negate any of the gains with CPU overclock at 4.2??

Would overall performance be better with a 4.0 CPU overclock and a 3.5 cache overclock - presuming that could be made stable?

Update after further testing - Still unstable with CPU at 4.0 and cache at 3.5. Leaving cache at 3.0 I'm running stable with CPU at 4.4 - max temp at 72 C - I think this is a relatively decent 5960x/8 core overclock on air. I am perplexed at the inability to raise cache ratio above stock. I find many posts saying to try for 1:1 or at least keep cache within 300-500mhz of CPU.

It just isn't happening with my chip & mother board...

 

[Alex Dorades]

Cache frequency can't be more than the CPU frequency. If you set cache more than cpu pc will crash or don't start at all. Its like Hyperlink on AMD Platform Motherboards. Look at this table which is a overclocking guide from my MSI Z97 MPOWER MAX AC.

 

[wyliec2]

Cache frequency can't be more than the CPU frequency. If you set cache more than cpu pc will crash or don't start at all. Its like Hyperlink on AMD Platform Motherboards. Look at this table which is a overclocking guide from my MSI Z97 MPOWER MAX AC.

Maybe I wasn't clear - my CPU OC is always higher than Cache OC.

I have an I7-4770k with a CPU OC of 43 and Cache OC of 40 - this is within the general guideline of keeping Cache within 300-500 MHz of CPU.

On my 5960x - CPU OC is now 44 and Cache OC is 30 - so very far apart. Any attempt to raise the Cache OC results in instability. With continued reading, I have found suggestions that while Cache OC can increase performance in some situations, CPU OC has the most impact. I'll probably take one more attempt at raising Cache OC to 35-38 with additional voltage increases - if that fails, I'll just stick with Cache at default 30.

The CPU OC at 44 with Cache at 30 and low volts/temps is a solid 24/7 build...the differential bugs me but I probably just need to get over it!!

 

[Alex Dorades]

I know what you mean. I think its a voltage one. Try to rise voltage more. If you rise voltage it have to working. Maybe you don't reached the point of voltage that the system needed to work stable.

 

[wyliec2]

I know what you mean. I think its a voltage one. Try to rise voltage more. If you rise voltage it have to working. Maybe you don't reached the point of voltage that the system needed to work stable.

After an evening of effort I am going to be calling it good with:
CPU OC = 44
Cache Stock = 30
VCore = 1.22
Prime95 stress temp max at 72C

This is a good 24/7 clock - on my benchmark application processing 24Mb RAW photos this gives me a 13% performance increase over stock. I was never able to get a 35 Cache OC stable and the one benchmark I ran gave me less that 2% additional improvement - this was with voltages that pushed Prime95 to 84C max temps before BSOD (I'm running P95 v26.6 BTW).

FWIW - my benchmark results (same 6 RAW images, with input, working cache and output on separate SSDs) are:

4770k CPU 4.3/Cache 4.0 277 seconds
5960x CPU 3.0/Cache 3.0 190 seconds (stock)
5960x CPU 4.4/Cache 3.0 166 seconds

Bottom line the 5960x OC is 40% faster than my previous 4770k OC machine on an apples-to-apples comparison.

The 40% bump is very expensive - my only justification for doing this was my wife needed a new machine (she gets my 4770k) and it's a hobby I enjoy....

 

[Alex Dorades]

Ya... Have fun...