Chasing my max OC - FX-8 Overclocking

[Guest]

FX-8320

MSI 970 Gaming Motherboard

Corsair Vengeance 1600MHz

XFX R9 390 Double Dissipation

 

Dictionary:

Spoiler

 

OC – Overclock

 

HT – Hyperthreading

 

NB – Northbridge

 

SB – Southbridge

 

V – Volts/ millivolts

 

FSB – Front side bus

 

Memory - RAM

 

 

Disclaimer: I am no expert. This is on air. Temperatures and daily driving the OC take priority over getting through a benchmark for epeen growth.

 

Also – my application of OC’ing is limited both by thermal levels and my motherboard. Motherboard power phase delivery is something others should consider when OC’ing. The power phases on each board vary and have a lot to do with what kind of voltages, stability, and OC’s you’ll be getting.

 

My personal limit for voltage is ~1.45v on the CPU core. If you are liquid cooled, etc., just live in a cool place, or have a better motherboard – you’ll be able to push this further. My ambient temperature is ~25.5c and I can get okay temperatures up to ~1.46v, but at that voltage my desired clock speed is 4.8 Ghz, and both the voltage and the frequency increase are adding a bit too much heat in my current climate, etc. Generally, I have identified a “wall” in terms of OC’ing around 4.8Ghz.

 

On the subject of hitting a wall, I will delve a little further into what I mean. The relationship between voltage and core frequency is an exponential curve/growth. The higher the clock, the voltage you’ll need to achieve that clock will be exponentially growing. For example, I can hit 4.7 on 1.44, but for a stable 4.8 I need ~1.48v+. That type of voltage increase for 100MHz increase is simply not worth it for my usage. It won’t be noticed, my thermals are unfavorable, and the longevity of the CPU/Motherboard is compromised.

 

Now, I’ve tried FSB overclocking and multiplier overclocking. What worked best for me was a combination of both. You can easily achieve a standard multiplier OC and be a happy camper. I will explain why it is nice to use FSB next.

 

Using the FSB increase will allow you to reach a higher clock on CPU-NB/HT frequency. This is the primary point of using FSB increase. There is up to 5% performance increase existing in CPU-NB/HT/Memory OC’ing in my specific experience with this chip and motherboard.

 

Note: The CPU-NB frequency just won’t boot above x13 (black screens), however if the FSB frequency is pushing the clock of the CPU-NB it can achieve like frequencies of a x13 multiplier.

 

Upvolting the CPU-NB/NB/SB needs to be done with caution. In most cases it will reduce stability. You would think that on the verge of a stable OC, upping the voltage to support these channels would be helpful, but anything other single notches above stock has given me issues with my, somewhat, moderate OC.

 

So what has worked best for me? I will outline exactly what is working and why it is working.

 

Using a FSB of 206 with a multiplier of 23 is how I am getting stable and favorable results. My best results ever were using FSB of 210 and multiplier of 22.5. Why can’t I run the better OC, which actually has less core clock frequency, but better overall results? The memory/CPU-NB/HT frequencies are causing instability (I am unable to pinpoint exactly where, but the CPU-NB frequency definitely gets finicky near/above 2600 and the ram speed exceeding the boards limitation of 2133 seems to be causing problems as well).

 

Edit: I have acquired knowledge of there being voids in the FSB clock that simply won't achieve stability, for instance the 210 not working but my later settings of 216 working. It's mostly trial and error, but different frequencies will behave more appropriately than others.

 

What are the results? With both GPU/CPU OC’s results in ~1700 points in firestrike score increase over stock. 400 of which were a direct result of CPU-NB/HT/Memory OC’ing.

 

Stock: http://www.3dmark.com/fs/7206865

Daily Driving OC: http://www.3dmark.com/fs/7737463

 

Tips and Tricks:

Spoiler

 

  Turn power saving options off, etc.

 

o   These are fairly typical recommendations you will see – I did not notice much of any difference when doing so.

 

·      Disable turbo’ing

 

o   Pretty much a must do

 

·      Set voltage to ~1.45v with a decent air cooler

 

o   Nearly any $30+ aftermarket cooler will be able to handle these voltages

 

·      Find your max multiplier OC

 

o   Go ahead and start at 4.5 GHz – run some stability tests to ensure it is stable (only if you really bit concrete will you not be able to run 4.5 GHz on 1.45v)

 

o   I have pretty much benchmarked stability within firestrike – if I fail on the physics portion then I am not stable – if I pass I am probably stable but will follow up with subsequent stress testing

 

·      Monitor temperatures

 

o   If you are happy with the temps and achieved stability in the previous step (should not exceed 65c on the core, however this should only be temperature spike range and 62c is safe operating temperature) then continue to bump up the frequency

 

o   If temperatures are already on the high side/threshold of safety – then go ahead and keep it at 4.5 GHz and notch the voltage down a step at a time and retest stability in order to optimize the least amount of voltage to run your specified OC.

 

·      At this point you basically want to rinse and repeat

 

o   Keep raising frequency until you lose stability – then back it down or increase voltage if you have temperature headroom

 

·      At this point you should have reached your maximum multiplier OC and optimized the voltage to be as low as possible while still maintaining stability (still want a bit of headroom for it, however)

 

·      Now you want to start adding in your memory OC – my board is rated for 2133 – and will accept up to about 2250 before becoming unstable

 

o   I would go ahead and set it 2133 if your ram is capable

 

·      Then, you’ll want to dial in CPU-NB and HT overclocks through FSB increase

 

·      Set CPU-NB to x12 and HT to x13

 

o   I’m not actually sure having the HT at x13 with the CPU-NB at x12 actually benefits anything – I need to do further testing, but the BIOS indicates that the CPU-NB needs to be higher or equal to HT. This alludes me to there being no additional benefit in having these values unequal, despite being unequal at stock.

 

o   Generally I haven’t found voltage control to help in this area, just keep it on auto until you can further pinpoint areas of concern

 

o   Like previously mentioned, voltage increase actually made me fail stability testing where stock voltage did not.

 

·      The higher the FSB the lower the multiplier you’ll have to set – just note the core frequency you can achieve with stability and try to match it with a slight increase in core frequency.

 

o   For instance, if my max multiplier OC was with stock FSB of 200 and a multiplier of 23.5 (4.7 GHz), then I want to dial back the multiplier and dial in FSB to get something that is greater than 4.7

 

o   So I would reduce multiplier to 22.5 and increase FSB to 210 resulting in a 4.725 GHz OC and test stability

 

o   Even equivalent values to 4.7 should be yield additional performance, but I am simultaneously attempting to find my max clock speed for the voltage that I have deemed safe and ideal (So even an FSB of 209 and multiplier of 22.5 will increase performance (resulting in core clock of ~4.7 GHz))

 

o   This lets you nudge the core clock up instead of incrementing in 100MHz – in turn, allowing you to find the threshold on the clock frequency at a given voltage level

 

o   NOTE: I realize that some tutorials are going to have you use FSB exclusively – but I simply could not get anything to work above 225 when testing – and this required losing performance.

 

·      Try different variations of FSB and multiplier until you find the max number you can get the core clock/CPU-NB/HT, while still achieving stability.

 

o   So pretty much rinse and repeat the aforementioned method of testing stability.

 

o   Note: CPU-NB/HT do not like being above 2600/2900 respectively (on my motherboard)

 

 

Basically, all of my testing has taught me that at the higher echelon of OC’ing – you’ll get more performance out of tweaking and maximizing the CPU-NB/HT/Memory frequencies, even at the cost of core clock in some situations. I have dropped core clock and achieved higher CPU scores, albeit, not by a significant amount.

 

My Final stats are:

FSB: 206

Multiplier: 23

Memory: 2196

DRAM Voltage: Stock (auto)

VCORE: 1.448V

CPU-NB: +.005

NB: 1.12

1.12

 

Some of these values are somewhat arbitrary, as I think left on auto(stock) would result in no altered results. Also, you may have to bump up your ram speed to achieve a stable OC on your memory (mine is rated at 1.65V, but I lost stability when upping the voltage).

 

Well, I hope this was somewhat helpful to anyone trying to get more out of their FX series CPU’s to tide them over for new Zen architecture. Let me know if you have any critiques or would like to add anything – I am open to learn and want people to have the best information they can.

[Dabasepc]

How Do I Set Adaptive Voltage ?
in the OS, no matter what is my current frequency, the voltage stays at 1,48 v

In the power saving thingy, the minimum is 5% and max 100%

Same Mobo, Same CPU.

[Nena Trinity]

You should be aware OCing on the MSI 970 Gaming board is not the smartest thing to do if you go past 4.5Ghz it may fry the VRM or worse... (I am not sure how much max voltage should be but I would not go over 1.45v...)

[Necrodead]

Nice OC. I got my 8320 to 4.8, but that took 1.48v(1.512 under load). The only reason I can run that is because of a massive water cooling system and dedicated motherboard fans on the sabertooth 990FXA. I didn't get good results out of FSB overclocking, so im just using a multiplier of 24 x 200. Also have a 1600mhz ram kit running at 1866, ram speeds seem to help these cpu's when overclocked very high.

[Guest]

1 hour ago, Necrodead said:

Nice OC. I got my 8320 to 4.8, but that took 1.48v(1.512 under load). The only reason I can run that is because of a massive water cooling system and dedicated motherboard fans on the sabertooth 990FXA. I didn't get good results out of FSB overclocking, so im just using a multiplier of 24 x 200. Also have a 1600mhz ram kit running at 1866, ram speeds seem to help these cpu's when overclocked very high.

Thanks, that's exactly how much voltage I need for a 4.8 too - and I do not feel comfortable running that much voltage on this motherboard. (I don't think it's stable for long periods of time - this board is just not that great as @Nena360 pointed out.)

[Guest]

5 hours ago, Dabasepc said:

How Do I Set Adaptive Voltage ?
in the OS, no matter what is my current frequency, the voltage stays at 1,48 v

In the power saving thingy, the minimum is 5% and max 100%

Same Mobo, Same CPU.

I honestly haven't done it - so I don't have any good advice on how to do it. I just run my max clock 100% - and when usage is down temps still drop to ~22c on the core.

 

I have changed my settings recently to 

 

FSB: 216

Multiplier: 22

Clock speed: 4.752

CPU-NB: 2592 (x12)

HT: 2808 (x13)

RAM: 2014 (1866)

VCore: 1.46 

CPU-NB: ~1.3

RAM: 1.64

NB: stock

SB: stock

[Necrodead]

58 minutes ago, Alexokan said:

Thanks, that's exactly how much voltage I need for a 4.8 too - and I do not feel comfortable running that much voltage on this motherboard. (I don't think it's stable for long periods of time - this board is just not that great as @Nena360 pointed out.)

I've even had gigabyte 990's fail to overclock these fx chips due to thermal throttling of the mobo. I've got some 40mm noctua's pointed at the heatsinks that keep the mobo about 30-35C instead of 70C+ that it used to be without. 

I'm going to try to get some more increases out of the NB and HT overclocking tonight, so thanks for the info, I didn't know that would help.