8350 OC on 4 cores?

raymix

Hi there!

Quite busy at work and studying lately to test this myself, so I come with question:

My current highest clock is 4.5Ghz with very slight bump in volts, however 4.6Ghz is completely unstable no matter what voltage I feed it, the more I give it the longer it passes the test, but alas - always fails it. Also runs super hot.

If I were to disable 4 cores on my fx-8350, it would theoretically give me more cache per core, since it's shared, right? On top of that it should give me lower temps naturally, allowing for higher clocks.

Has anyone done this? Games I play (DayZ, PS2, Tera) only uses 2 cores, so I was wondering would disabling cores let me squeeze out more frames if I managed to OC closer to 5Ghz on air?

There's not much info on google about this theory, unfortunately

raymix

Nevermind, it works!

Made 3 profiles:
web - 2 cores @ 2Ghz .. still playing with volts, currently 1.175Vm gonna go lower over the weekend.
game - 4 cores @ 4.8Ghz ~1.38V.. 10min OCCT, gonna do more testing over the weekend
encoding/streaming - 8 cores @ 4.5ghz 1.375V

4 cores @ 4.9Ghz and 5Ghz failed OCCT within 5 seconds with 1.4 and 1.43 volts... these probably needs juice around 1.45-1.5V

Still quite happy with a "theory", tested Arma 2 boot camp mission "little bird", got nice 60-75fps with odd dips to 55fps.
This is gonna be a fun weekend tweaking.

dyigirl4help

I was able to get my 8350 to 5.4 using a sabertooth990fx r 2.0 cooled via a thermaltake 2.0 Pro AIO and open windows with an ambient temp in the room of around 3 degrees. I reside in eastern EU and this was in the middle of winter and the temp outside was around -15C. here is the validation file for my 5.4ghz run http://valid.canardpc.com/1izwdb. I am currently running at 4.5 24/7 easy (validation http://valid.canardpc.com/bmfm10 ) so if you have any OCing questions feel free to ask me. I know enough about OCing to know how little I really know But I am happy you got it sorted

raymix

Thanks, I do in fact have a question - would you rather prefer bus or multiplier method and why?

dyigirl4help

raymix wrote: »

Thanks, I do in fact have a question - would you rather prefer bus or multiplier method and why?

That is a broad question, what are your intentions and are you going for a one time *show your friend OC* or something more stable you can use 24/7 and not worry about it frying anything. Also what type of cooling, motherboard etc etc are we working with here.

I think that using a little bit of multiplier with a little bit of FSB gives you the best of both worlds, but you must keep in mind that when you increase the FSB you also increase the ram, CPU/NB, NB and HTT frequencies so you need to be really careful when using the FSB and only if you have sufficient cooling. And if you are a gamer, 1600mhz ram with low timing, something like 8-8-8-20 CR1 or 9-9-924 CR1 is the sweetspot and when you start increasing your FSB you will have to loosen those timings which may impact your FPS game performance. For a 4.5 OC on a AMD FX8350 with 1600mhz ram I think you don't need to mess with the fsb at all, but that is just my opinion. It also depends on your motherboard and if you use a SSD or not.

raymix

I asked because there are some people claiming that overclocking FSB would yield faster OC, which is kinda logical, since you are shortening the wavelength rather than just increasing amount of pulses. Problem for me with this is - a slight change in FSB will almost always result in me having to take out the battery, which is kinda annoying to say the least

My initial problem isn't OC itself, I was just wondering if anyone else have considered disabling 4 cores, making this chip essentially a quad-core with high cache and since temps go down - much higher clocks at safe volts and low temps.

When it comes to multiplier it's rather straight forward, but fsb OC requires me to modify few other voltages and have a bit of background knowledge on this. I have found tons of good info on this, unfortunately for me it's not dumbed down enough so scientific or engineer terms makes no sense to me, for example voltage offsets and ring loops etc. Wish I had oscilloscope and time for all of this like actual pro OCers.

dyigirl4help

raymix wrote: »

I asked because there are some people claiming that overclocking FSB would yield faster OC, which is kinda logical, since you are shortening the wavelength rather than just increasing amount of pulses. Problem for me with this is - a slight change in FSB will almost always result in me having to take out the battery, which is kinda annoying to say the least

My initial problem isn't OC itself, I was just wondering if anyone else have considered disabling 4 cores, making this chip essentially a quad-core with high cache and since temps go down - much higher clocks at safe volts and low temps.

When it comes to multiplier it's rather straight forward, but fsb OC requires me to modify few other voltages and have a bit of background knowledge on this. I have found tons of good info on this, unfortunately for me it's not dumbed down enough so scientific or engineer terms makes no sense to me, for example voltage offsets and ring loops etc. Wish I had oscilloscope and time for all of this like actual pro OCers.

I agree with you but unless you are doing extremely cpu/ram/gpu intensive tasks a mild multiplier only from 4-4.5 ghz for a fx8350 won't hurt. And I have compared both fsb/muti and multi only overclocks and for normal day to day use I saw no real differential to be honest. But it depends on your other peripherals

dyigirl4help

I also wanted to add that I disabled core parking so that all *8* cores are doing their thing and not just cores 0 2 4 6, but 0 1 2 3 4 5 6 7. I even added a core parking reg addition to my power options ->advanced settings, I can adjust as needed (pic included ). I understand that the integer cores share the fpu and L2, but this module design can be amended with a few tricks and modifications such as core parking mod which forces the chip to *wake up* instead of put half the modules to sleep..lazy chip this one is:D It really is too bad that AMD is moving towards the APU design. I actually purchased 2 fx8350 chips in case one dies on me, I am NOT loking forward to being forced to use an APU when I already own a GTX780-DC2OC-3GD5, what would be the point of having a CPU with a GPU stuffed inside. AMD would make such great strides like they did back in 2000~ with their dual core if they only got their hat out of the trunk:pac:

justjustin

dyigirl4help wrote: »

I agree with you but unless you are doing extremely cpu/ram/gpu intensive tasks a mild multiplier only from 4-4.5 ghz for a fx8350 won't hurt. And I have compared both fsb/muti and multi only overclocks and for normal day to day use I saw no real differential to be honest. But it depends on your other peripherals

Could you elaborate on this a little if you don't mind?

I had been at 240 x 20 for months, but after getting a second Gpu and crossfiring I was getting terrible gpu usage and frame lag.

Over the last while I've been messing around with some different OCs but nothing really helped. It felt like the cpu was throttling but it wasn't. Also, I've always tried keeping HT/NB in or around 2400.

Two overclocks that were very different while gaming were these:

240 x 19 (4.56ghz), HT 2400, NB 2400 and
300 x 15 (4.5ghz), HT 1800*, NB 2400

Huge difference in general gaming for me with the high FSB, but maybe it's down to something else? I can't understand why my HT won't stay at 2400 either, it just auto drops back to 1800 for some reason. If I try setting it higher it will drop back to 1600, but why drop to 1800 when I set it for 2400

With the 300 FSB, windows also boots about 2secs faster from SSD :cool: