Advice needed - Gaming on battery issues

So, I've got a Clevo P150HM with a GTX560m and I've been battling the issue of getting some form of gaming performance on battery. Thus far I've created a custom VBIOS which sets the P(8) state (Ie the battery power state) to 500mhz and the memory to 800Mhz (trying to make it identical to the fully-clocked state crashed the card, on both battery or when switching on AC - I'm not sure why).

This seemed to make the card capable of gaming performance on battery - the other day I had Skyrim running at around 30-40fps in 1080p with fairly decent settings and The Witcher was pretty much running at a solid 60 for most of the time. I'm aware this kills the battery pretty quick but since I only need it for an hour if that while travelling on the train to and from university I'm OK with that.

The problem I've got here is consistency.. sometimes it hardly works at all, with Skyrim in single-figure FPS at times and other games showing similar issues. Then randomly I was getting 40fps. I can't seem to figure out what the hell is causing this inconsistency in framerate - lowering settings doesn't really seem to help - I can eliminate the following obvious things;

• Windows power management settings are set to high performance while on battery.
• Powermizer settings are set to 'maximum performance' in Powermizer manager for on battery state.
• Power management is set to 'max performance' in Nvidia settings (global)
• GPU-Z reports clock speeds at correct settings while on battery.
• Temperatures are well below thermal throttling levels.

Any thoughts? I can't for the life of me understand why occasionally I get good performance on battery with several games then suddenly I can't get it at all. It's completely baffling me.

 

the battery is not meant to be used for gaming as it cant handle the power and changing setting to let it do that will just cause damage.

 

Well the power is the same - it runs happily at 0.82v which is the default voltage for battery power anyway. The temperatures aren't dodgy either - could you explain in more detail how this is supposed to damage anything? I see my specific settings doing nothing more than running the battery down a bit quicker here.

 

Is there a particular reason why you need to game on battery?

I don't think it will cause any damage, but either you will use your battery up very quickly, or your hardware will be throttled by settings to extend battery life. Seems like a no win situation.

 

its common knowledge really.
im no expert but battery's are for use on the go for general use like surfing or work.
check with your reseller who will be able to tell you if its advisable or not.

 

Well, I guess it's kinda why I have a gaming laptop (other than my audio work which is seperate) - I figured the point would be that I could game on the move. I don't need super performance, I just have an hour's journey by train to uni every day and I'd like to be able to get a bit of gaming in on the way. Battery life isn't a huge concern, an hour or so is easily enough, the rest of the time I have charging sockets available. I'm fairly sure now it's not adaptive power being the issue either so I can get away with turning that back on and the laptop dropping down to the lower p12 state while not gaming on battery.

TBH the clevo's stock VBIOS was more damaging to my video card - it runs at 1v while on full power mode (AC adapter) and this was at one point causing the card to run at like 95C! I dropped that to 0.93V and it runs smooth as you like now without stupid temperatures.

As I said though, reduced battery life isn't my issue, I just want a bit of moderate gaming performance, so if anyone knows what other issues other than the ones I listed could be coming into play I'd be interested to know. It's not the games themselves as I tested it over multiple games.

 

Did you double check your windows Advanced Power Settings to make sure whichever setting you're using for battery uses Maximum Processor State 100% and 100% for whatever the NVIDIA equivalent of ATI Powerplay is?

 

You may have to disable Intel SpeedStep, usually in the BIOS. This will prevent throttling and enable components to run at full speed. You should also consider running at slower clocks for both CPU and GPU on battery and use a program like dxtory to limit framerates so your power consumption will be less. I've successfully managed to get BF3 to run off my DV6z with A8-3510MX with 6620G GPU at 30FPS and draining only about 35-40W. So on an 80WHr battery you're looking at about 2 hours of gaming. Otherwise if you don't limit power consumption it will drain your battery at max power which isn't good for battery and also will reduce your gaming time significantly.

Gaming laptops aren't really designed to be gaming on battery but just a portable gaming machine, typically plugged in.

 

Unfortunately there's no such option in the BIOS - it's a custom BIOS anyway made by ADK audio which has very few settings as it's optimised for pro audio use. I'd have thought they'd disable anything like that by default mind as stuff changing states and going to sleep tends to cause DPC issues and audio artifacts.

You're certainly onto something there though, the CPU seems to drop it's max multiplier to x12 when running on battery, often it's at x8. What this doesn't explain is the odd times I get when games run fine, I checked and both when it's working, and when it's not working, the CPU is still clocked at x12 multiplier. I've disabled all other non-essential processes, it's just damn weird, and driving me somewhat mental.

 

check the battery specs for power output vs maximum possible power draw your laptop could need if all components are running full speed.

seems likely to me that the battery wouldn't be able to supply that level of power.

your laptop's battery holds a certain amount of energy, but it can only deliver that energy at some maximum rate. may be related.

 

Hm yeah I've had a quick look into that, but I'd assume since I have actually got it working at a decent FPS on battery that the power draw itself is fine. The weird thing is there's no real variables that would be drawing more or less power that I can see - sometimes it decides I can get 40fps, sometimes it decides I can have 8. Once a game works at 40 or 60 or whatever it seems to act just like normal throughout the gaming session, I don't get any crazy dips or anything.

EDIT - well here's an odd thing - I noticed when I'm starting the PC up normally I get horrible FPS on battery but if I start a game on AC then remove the adapter the game performs just fine (slower than on AC of course but the battery clock is slower than stock so that makes perfect sense). Also when I start a game up with horribly low FPS and insert the AC adapter it instantly raises to full speed again, removing it has the same effect as before where the game drops a little but is pretty nicely playable.

Anyone have any idea why it would be behaving like this?

 

The only laptops that will have decent battery life while gaming is the new gen kepler cards with gt 640m and ulv cpu's. A gt 640m performs nearly just as good as your 560m at less then half the power consumption so if you really want to game on battery buy a mid range kepler card.

 

A technician told me before that gaming on battery assists in it's degradation. I don't recommend it. You will not enjoy gaming on battery anyway as it will drain very fast.

Good luck.

 

Optimally, what are you looking for here? 20 minutes or so of full power 3d? It's really not built for that, and I'm pretty sure your hardware is taking measures to protect the battery from the side effects of ultra-fast discharging

 

The key is to manage power draw. If you manage it appropriately it isn't so hard on the system. Even on my new Sager NP6110 I can get close to two hours gaming on battery depending on game and how I have it set up.

 

Yeah that's pretty much my aim, I realised quite early on when editing the VBIOS that trying to get the stock speeds on battery wasn't going to work anyway so I've kept the power at 0.82v (standard for P8 secondary power state on battery) and tried to see what kind of clock speeds I can comfortably get at this voltage. I'm not aiming for full-on gaming performance like I'd get on AC power, just enough to enjoy a bit of The Witcher (the first one) or something like that at decent resolution for an hour or so if needs be.

I've also noticed a higher clock speed on the P8 state reduces DPC latency issues which is good for audio work on both battery and AC because at 4-500mhz it tends to hover there on adaptive power while using cubase and plugin GUIs, when on the original 150mhz it tended to jump all over the place and cause some occasional spikes.

So basically I'm happy to drop the clock speeds a bit to find a sweet spot between gaming performance and power consumption, I'm just trying to solve the mystery of why it's being inconsistent with it.