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AMD Kaveri A10-7850K Overclock Guide - Page 120

post #1191 of 1334
Had some time to play with the chip.

I managed to get the iGPU stable at 900 Mhz @1.3V NB. Can't go any higher, even if I raise the voltage to 1.4V, it will eventually crash and will have to do a BIOS battery reset to get it to post.

Either way, I also managed to push the NB freq a bit higher, from 1800 MHz to 2000 MHz. There's no difference as far as I can tell in the 3DMArk benchmark, maybe 1-2 points, not noticeable at all.
However the jump from 720 MHz to 900 MHz has bumped my score by over 100 points. I think it's still a pretty decent performance increase for free.

I would like to know why running at 1028 MHz always crashes 3DMark11 and the ATI driver. Even 960 MHz does. As far as I've seen can't go any higher right now. Maybe it's my motherboard. It's a mid-range board, so I don't expect an $80 AsRock board to perform like a $120 Asus one.

So far I'm all ok with the temperatures. After finishing the benchmark at 1080p I still had 54 C thermal margin. That seems a lot to me. Should I try raising the NB voltage even more? I was quite surprisde 1.4V isn't enough for 1028MHz.
post #1192 of 1334
1.4V is already very high for the NB. I run mine at 1.3375v which is already pushing it. As you say, it may have a lot to do with your board and its ability to supply smooth voltage.
post #1193 of 1334
I've just noticed that these NB voltages above 1.35 are marked with orange, the ones exceeding 1.4 are red in Overdrive. I think this is still a balanced overclock for both the CPU/iGPU. No point in pushing it any further.

Altough, ASrock A-tuner shows voltages around 1.26V CPU VCORE while running Intel Burn Test at Very HIgh, this would mean that I could probably lower it a bit from 1.35V which is BIOS default for this, or I could probably raise the frequencies a bit, by 100-200 MHz probably, still got over 35 C thermal margin while running IBT. That's still a lot to overclock. I will however probably see thermal throttling if both CPU and iGPU are under load. WIll try running IBT and FurMark in parallel thumb.gif The whole idea was to get the iGPU running as fast as possible for a 24/7 workload and casual gaming. I'm still happy I could push it this far.
post #1194 of 1334
Here, if i put the NB voltage to 1.3, the microphone starts to make noise. Some gigabyte boards are pretty crappy and the NB have to be overvolted with AMD MSR Tweaker. Not the safest method, but works with care. And no RAM 2400Mhz with this board (F2A88XM-D3H). Nothing can stable RAM at this clock in this board.

My settings stable until now: CPU 4.0 Ghz (1.25v) GPU: 1028 Mhz (1.275v) RAM: 2133 CL9 (1.6).
post #1195 of 1334
Can anyone explain to me how to use the APU LLC (Load-Line Calibration). It's currently set to Auto on my board.
There's no help in the BIOS, neither it is in the user manual. It only says that this option will enable LLC.

My available options on the Asrock fm2a88x Extreme4+ are
- Auto
- 1/2 VCORE
- 1/2 NB
- 1/2 VCORE + 1/2 NB
post #1196 of 1334
Attempted layman's explanation:

LLC is not a voltage increase mechanism, but something to combat vdroop - the phenomena of temporary voltage fluctuation when your proc changes states, so the listed voltage isn't the same as the one you set it.

http://zannyland.blogspot.sg/2012/11/a-guide-to-asrock-ami-uefi-fm2.html
Quote:
APU Load-line calibration: This is used in modern cpus to offset vdroop. Only use load line calibration if your voltage isn't dangerously high - traditionally, your given voltage is a fixed limit that the processor won't pass, but may dip below (droop) especially under constant heavy load. LLC will up voltage to offset droop, which means your rated voltage isn't your limit anymore, but you have less chance of voltage dropoff under load. So use LLC at low overclocks but avoid it with higher ones where the voltage spike it causes puts the cpu over safe limits.

Say you have a vcore voltage of 1.3v default, and an LLC of 1/2 vcore. On a state change, an extra 1.3v/2 (or 0.65v) is assigned to vcore. On the off chance you don't get a vdroop during that operation, your core will for a second or so operate at target 1.9v, or maximum allowed voltage for the slot, whichever is lower. It's best to leave this in Auto, I balk at anything above 1.5v these days.
post #1197 of 1334
Quote:
Originally Posted by GreatChicken View Post

Attempted layman's explanation:

LLC is not a voltage increase mechanism, but something to combat vdroop - the phenomena of temporary voltage fluctuation when your proc changes states, so the listed voltage isn't the same as the one you set it.

http://zannyland.blogspot.sg/2012/11/a-guide-to-asrock-ami-uefi-fm2.html
Say you have a vcore voltage of 1.3v default, and an LLC of 1/2 vcore. On a state change, an extra 1.3v/2 (or 0.65v) is assigned to vcore. On the off chance you don't get a vdroop during that operation, your core will for a second or so operate at target 1.9v, or maximum allowed voltage for the slot, whichever is lower. It's best to leave this in Auto, I balk at anything above 1.5v these days.

No!

The load-line adjustment changes the compensation which is applied to counter the voltage droop.

e.g. When your CPU draws 50A of current at 1.325V with default load-line setting the voltage droop is 0.065V (50 * 1.3mOhm).
The default load-line resistance (Rll) for AM3+ and FM2/+ parts is 1.3mOhms. On FM2/+ platforms the specification demans that load-line adjustment is supported: 100%, 80%, 60% and 0% of the original. If the load-line setting is changed from the default 100% to 80%, the Rll will become (virtually) 1.04mOhm (1.3 * 0.8). If the conditions remain identical (50A @ 1.325V) then the voltage droop will reduce from 0.065V to 0.052V.

In reality the Rll doesn´t change, however the amount of compensation applied by the controller does.
When the load-line is set to default settings the VRM controller does not take any measures to compensate the droop.
When set to 80%, the VRM controller will boost the voltage by up to 0.013V (50A @ 1.325V).
post #1198 of 1334
Aha thx and sorry. Some things on mobo I just never touch. -.-
post #1199 of 1334
Thanks, that what I've found out on the internet as well.

I think I'll leave it on auto. Tried setting it once to 1/2 VCORE + 1/2 NB and my PC wouldn't post anymore, had to take out the battery to reset the settings. I was afraid that I burnt my APU since I couldn't see any output on my monitor smile.gif Besides I have no options for it in BIOS to set like you said 80%... I gave up playing with this setting since I don't have money for another MB + APU if I kill these.

I've seen in the thread that it's possible to disable Throttling only by changing CPU voltages wis AMD MSR Tweaker? I've noticed that sometimes when I left my PC on, during idle I sometimes found it frozen, and had to reset the PC. Is this being caused by some voltage drops in the idle state? IBT runs fine on Very High - 10 passes.

C6 state is disabled from BIOS, so it is Throttling, AMD Cool'n'Quit is left turned on.

I wish there was more documentation on how to OC these APUs.
post #1200 of 1334
Looks like BIOS Rev. 2502 for the ASUS A88XM-Plus had some issues which were addressed with Rev. 2701,
Quote:
A88XM-PLUS BIOS 2701
Fix D.O.C.P. function fail when selected memory frequency is 2400 MHz

Which was exactly the problem I was having. I just flashed to this latest Rev. Now I'm holding stable @ 4.5ghz CPU clock, x45 Multiplier, 100mhz Bus, 2400mhz DRAM @ stock X.M.P profile, NB @ 2000mhz, and I was able to bump the iGPU clock up to 960mhz. CPUz is still reporting iGPU memory @ 333mhz, must be a glitch.

Once I upgrade my cooler from the Corsair H50 I've got now, and get a new case, I'll see how far I can push this APU. I'm looking at getting either a be quite! Dark Rock 3, or a LEPA AquaChanger 240mm radiator, for cooling, and either a Fractal Design R5, Fractal Design Define S, or a be quite! Silent Base 800 case.

Not quite sure yet what I'll get, all I know is it's time to upgrade. I've gone through 3 builds in this 12 year old X-Blade case, and it's really showing it's age. I'm aiming to get as quite as possible, with maximum cooling.

Right now I've got two 120mm Scythe Slipstreams in push/pull config on my H50, and when they both spool up to 2000 RPMs, the back of my case sounds like a turbine. Those fans do push some air though...

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