boosting turbo multiplyers in XTU for Mobile Haswell

I haven't found a guide here to do this, but I'm interested in tinkering a bit and maximizing CPU speed. I have a new machine (Mythlogic Nyx1713/Clevo P170SM) with a 4900Mq CPU and the turbo speed can be increased by 600Mhz theoretically. How to do it though? There are lots of sliders in XTU. I've googled and read many threads and dabbled and had Watchdog (thankfully) shut down the machine when I've gone astray. So, how would you get close to that 600Mhz boost?

 

You need to adjust the cpu offset voltage along with the TDP.

 

Thanks for the reply Meaker. I see the "Dynamic CPU voltage Offset" slider, but there is no TDP slider and I'm not sure what would be analogous. The Processor Current Limit? The Core Voltage? The TDP is like the set heat ceiling isn't it?

 

In the Bios, I have many options for adjusting. Under the CPU option, there is the CPU Voltage Offset, and then the CPU Adaptive Voltage Target. So would the latter be the TDP, and if so, do you increase them by the same amount?

Another question is: should I bother with XTU if I can make all the changes directly in BIOS?

 

I don't have access to OC my 4900 in bios, but I use XTU. I have it set to 42x across all 4 cores just as a test. In order to get this however you have to do as meaker said and up the dynamic voltage offset. I have it up 15mV on both the dynamic voltage offset, and processor cache voltage offset.

 

Thanks Talon. Have you stressed these settings. If so, what was your average CPU speed?

 

So I just tried your settings Talon and stressed it for 5 min in XTU and it passed and temp maxed at about 81, but the speed comes way down, running on average at 3.39, which is exactly what it will do when stressing it without making any changes. If the Turbo has been increased, and it's running in Turbo mode, shouldn't it be running at those speeds (4GHz) when stressed?

 

Yep thats the issue I've been running into myself haha. Can't seem to get it to hold those settings permanently.. When I try and game the clocks won't stick fully once loaded. I'm not sure if I just need to go crazy and up the power or which settings to fully adjust. Was hoping more people would have more knowledge but I haven't come across many posts with useful info.

 

So I've made progress, but first a disclaimer: I DON'T KNOW WHAT THE HELL I'M DOING! i'M FLYING BLIND. WHAT I'VE DONE MAY BE DEAD WRONG AND CAUSE DAMAGE TO YOUR MACHINE!

Back to my situation: new Clevo P170SM w/ 4900mq. Straight out of the box, when stressed, CPU runs at 3.3-3.4GHz. In CoreTemp the multiplier drops from 36 to 33 immediately upon starting the XTU test.

The biggest change I've made was reducing the Dynamic CPU Offset Voltage (DOV) to -.49. As soon as I did that, everything got better. The stress test ran at 3.6GHz for the duration, and Coretemp showed the multiplier staying at 36. Great! It's an extremely humid day here with temps around 78 (25), but max temps under stress were low 80s.

I'm not sure what was happening, but I'm guessing it has to do with the set TDP of 47W. At stock setting, it was bumping up against that and even though XTU was showing no throttling, it was reducing the multiplier and essentially throttling.

Next I started increasing the Turbo Boost Max Power(TBMP), which I think acts as the TDP setting. I also increased the Processor Current Limit(PCL).

After some incremental tests, I've arrived at these settings: DOV: -81mv
TBMP: 60W
PCL: 84.25A
Multipliers: 40, 39, 38, 38

And it works. XTU stress test runs at 3.8Ghz for the duration, CoreTemp shows the 38xmulti, but temps do get a bit high, reaching 91 at the end of a 5 min stress test (although it does seem that the fan doesn't kick into its highest setting until temps reach this level and just after the temps hit 91, they came down to 85).

So I'm pretty happy with this, but I'm fearful of going further. Am I doing anything really dumb as far as my settings go? Do the max power (60W) and current limits (84.25A) seem dangerous? I have watchdog enabled, and it's worked before, but I'm not sure how much I can trust it to prevent me from doing something irreparable.

 

Okay, the excitement is palpable - but you got a 0.4 to a 0.5 GHz speed boost (~12%) by increasing the TDP by ~28%...


No matter how safe you make an extreme sport - if you keep doing it, sooner or later you'll become a statistic... (or in this case; your cpu/notebook).


Nobody really knows the limits of Haswell yet: make sure you're documenting your adventures fully for those that will come after you...


(84.25 Amperes inside a 1cm piece of silicon!!! Crazy).

 

Thanks for the input. Yeah, I know this isn't a huge bump, and the Current Limit increase does make me nervous. At stock, it's set at 73, so it's like a 13% bump. As to the speed increase, some things in LR can take 5-8 seconds and are almost entirely CPU dependent, so every little bit helps. I don't game, and LR maxes the cores out at around 60% load, so I don't see the CPU getting lots of max cpu load. Most of the time, I use the machine in balanced power setting and the CPU speed comes way down. It's only when I'm editing files that I'd put it in Max Performance mode.

But you're right, this could all be serious folly. Is the current limit really in AMPs? Stock is 73 AMPs? How can that be pulled from the wall?

 

Don't get me wrong: I'd kill for 13% more productivity in LR5 too - but I wouldn't risk killing my system to do it though***!


*** That is, ahem, er, ah - I wouldn't risk my systems any more....


(Yeah I was young(er) and much more foolish too once upon a time - killed two ($8K and 14K) desktop's because the O/C'd performance/productivity was addictive. Never did save more in time/work (while O/C'd) than what I wasted getting those systems back into production ready status again - and that was over several months of O/C'd 'bliss').


If you can afford the hardward/time costs of killing (is this your only system?) a system for giggles, enjoy it while you can.

Good luck.

 

Latest settings: Voltage offset: -.92mV TDP 68W Current: 87A Multipliers: 40, 39, 39, 39

Gets hot but all 4 cores hold steady at 3.9GHz under stress.. It is odd that the fan doesn't kick on to its highest speeds until temps are over 90. Is there a way to manually set the fan?

 

you are exponentially exploding ur cpu power efficiency for peanuts of perf haha

have a 4700HQ and run at 3,4 ghz forever on four cores just by putting 34x max multiplier and -100mv. 64W at the wall. 75°C max. Silence. What else.

 

So you'd move the TDP to 64, but don't touch the current? That's the sort of advice I'm looking for. At -100mV, 64W and 39, 38, 37, 37, I get steady 3.7 on 4 cores and max out at 85.

 

Nope didn't touch the tdp, still 47W, XTU doesn't let me edit the tdp value anyway. 64W is the consumption at the wall.

edit : i can go -110mv, seems stable, shave like 10W+, tried voltage cache offset at -100mv also, works but it barely shave 1 or 2W watts more, it's just cache, so not a big impact.

Well, no, -110mv crashed at some point, but 100mv is rock stable.

 

I see, the wall as in the outlet. Yeah, at 47W and -100, I get steady 3.6 which is all I was looking for when I started this, but I'm wondering how much I'm stressing the system by increasing TDP(turbo boost max power) with an undervolt, if the main usage I have is LR which only ever puts about a 60-70%load on the CPU and even then it's like a heartbeat, up to 60 down to 10, never a sustained load. In use I never see temps rise above 70-75. Aren't these settings upper limit settings? Under balanced power settings while surfing the web or using Word, the CPU is way down around 1.5Ghz or lower. Do these XTU settings increase the stress on the system in these conditions?

 

3,6 ghz at 47W and -100mv is damn fine, you are losing ur time imo to try to gain peanuts of perfs by trying reckless settings, 3,6 ghz is already a powerhouse and still efficient energy wise. But hey, do what u want, no one can stop an OC junkie

 

I can stop whenever I want! I can!

I'm curious (like the cat) and learning as I go and playing with my new toy (first in 3.5 years), but I'd rather not break my new toy either.

As to what goes on under the hood, I've been reading lots of technical stuff, most of which is new to me. I saw one OC page talking about the relationship between volts, watts, and amps. The formula was AxV=W and the goal was the achieve this equation. That got me messing with the settings: 73A x .825(vid)=60W. I don't know how the -.100mV offset factors in (the vid becomes .725?) but the relationship between the A and the W seemed to work when I tried upping the multipliers... This is an example of that adage about the danger of a little bit of knowledge.. Or curiosity and the cat.

As I said though, what started me on this wasn a desire to have all 4 cores run at the 3.6 turbo frequency at stock, so I'll probably just settle into that... Any day now.