Question on AVX and LLC for overclocking

[dburne]

Hey gang,

Been reading up and watching some youtube vids on overclocking these newer motherboards. 

I am about ready to begin overclocking my new system. Currently at stock settings while running stress tests, with all 8 cores/16 threads my i9 9900k is running at 

4.7 GHz on all cores , voltage is reading around 1.23v, and temps appear good - in the mid to upper 60's.

Some of this stuff is certainly new to me coming from overclocking an X 79 chipset board and 4820k processor.

 

AVX - as I understand if offset it set, the cpu speed will drop when AVX applied by 100 MHz per each AVX number offset. So offset of 2 it would drop by 200 MHz.

If the game or application does not use AVX then it will not apply. 

So are you guys setting an AVX offset or just setting it to 0?

 

LLC - Load Line Calibration - I have seen recommendations of starting around 6 and working up from there as needed. This is just basically 

another form of vdroop for the most part? Do you guys use LLC?

 

Thanks for any tips on these two items.

Even at stock clocks on this rig, I am extremely pleased with the VR performance I am already seeing. But of course a little more never hurts.

 

 

Edited January 24, 2019 by dburne

[Guest deleted@134347]

3 hours ago, dburne said:

Hey gang,

Been reading up and watching some youtube vids on overclocking these newer motherboards. 

I am about ready to begin overclocking my new system. Currently at stock settings while running stress tests, with all 8 cores/16 threads my i9 9900k is running at 

4.7 GHz on all cores , voltage is reading around 1.23v, and temps appear good - in the mid to upper 60's.

Some of this stuff is certainly new to me coming from overclocking an X 79 chipset board and 4820k processor.

 

AVX - as I understand if offset it set, the cpu speed will drop when AVX applied by 100 MHz per each AVX number offset. So offset of 2 it would drop by 200 MHz.

If the game or application does not use AVX then it will not apply. 

So are you guys setting an AVX offset or just setting it to 0?

 

LLC - Load Line Calibration - I have seen recommendations of starting around 6 and working up from there as needed. This is just basically 

another form of vdroop for the most part? Do you guys use LLC?

 

Thanks for any tips on these two items.

Even at stock clocks on this rig, I am extremely pleased with the VR performance I am already seeing. But of course a little more never hurts.

 

 

 

I only use AVX=0 because i have delidded/liquid metal/relidded my cpu so the temps are very nice at full load (~50-55C).  If yours spike up to 75-80C then I'd suggest going with AVX=1 or 2.

 

As far as LLC - haven't touched that one as I don't have any insight in to my vdroop. I probably should monitor it but I'm just lazy..

[dburne]

Ok thanks much!

[ZachariasX]

3 hours ago, dburne said:

So are you guys setting an AVX offset or just setting it to 0?

 

BoX uses AVX and it runs as fast as your AVX units. When I set my clocks to 5 GHz and AVX offset 3, I get the same as with clocks at 4.7 GHz with AVX offset 0, but like that I have a more stable system.

 

AVX consumes considerable power. In my experience by using the offset, you can get higher stable clocks. For bragging rights I guess. 

 

I didn‘t play much with LLC. Anything I could do there was not a limiting factor for clocks. Or lets say, differences woukd have been minimal.

[dburne]

1 hour ago, ZachariasX said:

 

BoX uses AVX and it runs as fast as your AVX units. When I set my clocks to 5 GHz and AVX offset 3, I get the same as with clocks at 4.7 GHz with AVX offset 0, but like that I have a more stable system.

 

AVX consumes considerable power. In my experience by using the offset, you can get higher stable clocks. For bragging rights I guess. 

 

I didn‘t play much with LLC. Anything I could do there was not a limiting factor for clocks. Or lets say, differences woukd have been minimal.

 

Interesting, in my research from what I read it stated there were hardly any games out there now that use AVX. Yeah certainly sounds like IL-2 does.

In reading the idea behind the offset is to keep the cpu core temps below the thermal limit - when I game with IL-2 though my cores come no where near that limit so maybe I will try it set to 0 at first.

 

Edited January 24, 2019 by dburne

[ZachariasX]

1 hour ago, dburne said:

Interesting, in my research from what I read it stated there were hardly any games out there now that use AVX.

I was surprised as well. Yet it seems to me that AVX is rather popular amongst "3D games". About every more or less current CPU can do it, that helped I guess.  AVX512 however you can throttle as you want, it doesn't exist for practical purposes unless you compile such code yourself. Its Intel only and who in their right mind would code a game Intel CPU only? Ehm, even "certain Intel chips only".

 

 

[Alonzo]

On 1/24/2019 at 6:46 AM, dburne said:

AVX - as I understand if offset it set, the cpu speed will drop when AVX applied by 100 MHz per each AVX number offset. So offset of 2 it would drop by 200 MHz.

If the game or application does not use AVX then it will not apply. 

So are you guys setting an AVX offset or just setting it to 0?

 

LLC - Load Line Calibration - I have seen recommendations of starting around 6 and working up from there as needed. This is just basically 

another form of vdroop for the most part? Do you guys use LLC?

 

I have an 8086K and OC'd it extensively for IL2 VR.

 

I have run the chip at 5.1ghz (all core) with AVX of -1 and hyper threading switched off. A recent patch (3.007 I think) actually reduced AVX instruction usage by IL2, same patch that drastically improved VR performance. At that point I re-enabled hyper threading (it's good for other apps) and I ended up settling on AVX -2. Then 3.008 came and knackered it again, so I dunno if it's AVX or not. 

 

LLC helps with OC stability. You should use as low a number as you can get away with an have stable performance, because it basically juices the voltage going into your CPU. If you set it to 'Extreme' or a high number then your CPU is likely going to get more volts than you have dialled in in the bios, which might be bad news. Especially for a 24x7 overclock, try to stick with a mid to mid-high number, not a very high number.

 

I've found that IL2 in VR is very picky about CPU stability. Various people will tell you you just need a 20 minute Blender test or something. In my experience that's fine for determining approximate stability of an overclock, but I need overnight Prime95 AVX torture tests in order to get real IL2 VR stability. Otherwise I was getting random crashes.

 

Personally I think game stability is more important than absolute OC, so even if you could handle something in theory it might be worth dialling back the OC by 100mhz, reducing voltage and gaining stability and reduced temperatures.

 

...and here's my gold standard review site, Gamers Nexus, including all sorts of very detailed info on how they OC'd their 9900K. They also did a delid and liquid metal which I would not advise, but it gives you an idea of what you might be able to reach if you were a professional reviewer/overclocker (!).

 

https://www.gamersnexus.net/hwreviews/3378-intel-9900k-cpu-review-solder-vs-paste-delid-gaming-benchmarks-vs-2700x?showall=1

 

Edited January 26, 2019 by Alonzo

[dburne]

Much thanks for the info guys!

 

I have spent all morning working on an overclock and stress testing in between. 

So far I have been able to achieve 5.1 GHz on all 8 cores  and appears very stable. Hyper threading still enabled.

Vcore setting of 1.23v.

AVX - 0.

 

Hit a wall trying for  5.2 GHz. Might could push through it but not sure I want to, went up to 1.30V on vcore and still hit the wall. Not sure worth it for just another 100 MHz.

Just flew three  Missions in my PWCG Career and even with graphics way up my VR performance was outstanding.

Very pleased so far.

 

 

 

 

 

 

Edited January 26, 2019 by dburne

[I./JG68_Sperber]

I have all settings Auto. 

5.1 GHz and 1,31 V.. Thats run very stable and fast. Max Temp 65°C