The impossible dream!

[Floatingshed]

Hello,

I live off-grid, using solar power and a petrol generator in bad weather (English summer!).

I need some advice on powerful yet lean PC's to allow me the best compromise of energy consumption and reasonable processing speeds when using complex filters in avisynth.
12volt machines if possible to remove the inverter/Psu heating system!

I don't understand the difference between a PC and a laptop in this regard. My PC is dual core 3Ghz, my laptop is dual core 2.5Ghz but the speed difference is utter madness. On a test script the PC gave 16Fps whereas the lappy gave 2.4Fps.

Any help and advice would be gratefully received.
Thanks.

[Motenai Yoda]

usually newest is more efficient too, and intel's cpus needs less power than amd's ones.
laptops use low voltage/low energy chips which means more efficiency and low power consumption but also mid low performance when compared to an hungry desktop cpu.

as you rely on a 12v input there are some picopsu psus which can drive up to 160W and are used on car-pcs.
also as a laptop need a dc input current, you can use a dc-dc converter to feed it.

[GMJCZP]

Another thing that makes the PC faster than a laptop is the hdd. A hdd laptop is usually 5400 or 5900 rpm, whereas a hdd pc os is 7200 rpm.
To compensate a little the difference could you put to the laptop a hybrid hdd.

[Asmodian]

A modern Intel desktop CPU can be undervolted, maybe even underclocked a bit, for significant power savings. Desktop CPUs are faster than mobile ones but use more power as well, laptop CPUs do generally have better performance/power but much worse performance/price. Still, I would use a desktop CPU unless very constrained and then get almost the best laptop CPU available/affordable. Leave all the power saving features on and the newest 6th gen i5/i7s are pretty efficient, performance hasn't gone up much but power use is down.

Ideally the mobile i7-6770HQ/6870HQ/6970HQ would offer the best performance/power, in part due to the 128MB of edram that acts as GPU memory and a level 4 cache. The desktop i7-6785R also has the 128MB of edram. The desktop i7-6700T is a nice low power option if you do not want to manually downclock and undervolt a i7-6700 for similar results, perhaps not quite as good but cheaper. :)

Do you need a GPU? The newest integrated Intel GPUs, that are part of any of these CPUs, aren't too terrible and lowest power option.

A solid state drive is much faster and much lower power than a HDD, fairly large ones are getting reasonably cheap as long as you do not need the fastest. Here again the newer drives are lower power, generally.

The display is also a significant part of the power use, make sure to use a LED backlit display at a reasonably low brightness. The smaller the better, read reviews about power usage before buying. ;)

Edit: Something like this for the power supply: picoPSU-160-XT (http://www.mini-box.com/picoPSU-160-XT)

[Motenai Yoda]

well avs filtering is a pretty cpu limited stuff, I don't thing an ssd can increase filtering performance as a generic hdd can afford over 100MB/s of throughput.

as desktop cpu side I will add 5775c too as is one of the most efficient
http://www.legitreviews.com/intel-core-i7-6700k-skylake-processor-review_169935/17

[raffriff42]

My PC is dual core 3Ghz, my laptop is dual core 2.5Ghz but the speed difference is utter madness. On a test script the PC gave 16Fps whereas the lappy gave 2.4FpsThe laptop will have a smaller and slower hard drive, could be low on memory, and probably most important: could be thermal throttling (https://www.google.com/search?q=laptop+thermal+throttling). Laptops build heat more quickly than desktops. They are rarely able to sustain their published performance specs over any significant period of time.

Also, consider total power consumed: lower wattage saves power, yes, but so does shorter time to completion. Your desktop encodes 6 to 7 times faster than the laptop; if it consumes anything less than 6 to 7 times the power (per unit of time) you are better off using the desktop.

[Asmodian]

well avs filtering is a pretty cpu limited stuff, I don't thing an ssd can increase filtering performance as a generic hdd can afford over 100MB/s of throughput.

as desktop cpu side I will add 5775c too as is one of the most efficient
http://www.legitreviews.com/intel-core-i7-6700k-skylake-processor-review_169935/17

The SSD recommendation was mostly for power savings instead of performance, at least for AVS workflows. The responsiveness for the OS and general use is also very nice.

I agree, any of the 5th gen i5/i7s with edram would be very good, the i7-5775C is a great CPU. Also the i5s are pretty good, e.g. the i5-6585R or the i5-5675C. Saddly it looks like all the 6XXXR CPUs are OEM only you need to buy a prebuilt system to get a Skylake with edram. :(

The big advantage, for power use, from Intel's 6th gen i5s and i7s is the DDR4 memory, which is noticeably lower power/performance than DDR3.

[johnmeyer]

I need some advice on powerful yet lean PC's to allow me the best compromise of energy consumption and reasonable processing speeds when using complex filters in avisynth.
12volt machines if possible to remove the inverter/Psu heating system!Most laptops are 18V DC input. If you can tap your solar array in a way to get 18 V, you can avoid the inverter. There may be some laptops with 12V inputs, but you'll have to research that.

There is no simple way to adapt a desktop PC to run directly from DC voltage (prior to the inverter) because it uses more than one DC voltage.

No laptop will ever be as fast as a good desktop, primarily for the reason that strikes at the heart of your proposition: power. A good desktop runs the CPU and GPU at really fast speeds, and this dramatically increases the power draw. This in turn increases the cooling requirements, and all the fans (or liquid cooling) suck up still more power. The ratio between laptop and desktop power draw is not trivial. Others who know exact numbers can chime in, but I think a high-end laptop is probably 1/6 the power draw of a high-end desktop (although "it depends" enters into any statement of this nature).

The other reason a laptop is your only real solution is the built-in battery. I'm sure you have power storage, but by having its own power storage, your laptop can be used at night without tapping into whatever off-grid storage solution you have created.

Finally, while it is a noble goal to go off grid, and it is fun to talk about, having consulted with several people who have tried to do this, even for survivalists or those who believes in some sort of Armageddon, the cold fact of the matter is that your off-grid solution will probably only continue to work for a few months after any major catastrophe: the inverters are the weak link, but the solar panels often fail due to thermal expansion and contraction. Therefore, I always recommend to simply install the panels, but use the electricity from the power company in the evening. Here in the states, most power companies will buy back the excess power you generate during the day, so you can still approach a net zero usage of electricity from the power company. You get to almost the same place as being truly off-grid, and avoid having to pay a fortune for a storage system.

You can also then buy the computer that you really need.

[Asmodian]

There is no simple way to adapt a desktop PC to run directly from DC voltage (prior to the inverter) because it uses more than one DC voltage.

Is this picoPSU not a good option? picoPSU-160-XT (http://www.mini-box.com/picoPSU-160-XT) 12V input, 160W continuous. It should be sufficient for an i7-6700 at stock or any lower power CPU, 16GB of 2400MHz DDR4, and a 1TB SSD.

It could be a nice lowish power encoding system for not too much money (still not a budget system), all running off of 12V.

[Floatingshed]

Great! Thanks for all the help and advice, I will do some more research and planning.

@johnmeyer: I don't have the alternative of a mains power supply, I am on a boat in the middle of nowhere. Beautiful and peaceful but it has it's drawbacks :)

[johnmeyer]

@johnmeyer: I don't have the alternative of a mains power supply, I am on a boat in the middle of nowhere. Beautiful and peaceful but it has it's drawbacks :)I had a good friend who lived on his boat year-round in Boston. Used a coal stove during the winters. Pretty rugged existence at times.

The 12V input power supply linked to would definitely avoid the Solar DC --> Inverter 220V --> Internal DC voltage conversions, but my reading of the specs indicates that it still does a DC-to-DC conversion in order to create the other voltages, and may even do this to create the 12V, the latter because it may make the assumption that the 12V input is not regulated well enough. This, BTW, is a huge deal for anything that you power directly from a 12V supply. Most products that plug into the cigarette lighter/accessory plug in a car still use some sort of regulation, because the voltage coming off the alternator is often quite a bit higher than 12V and can have lots of spikes and fluctuations.

Now that I know you are on a boat, I'd recommend that you get a laptop (space saving). Just make sure you get one with a decent graphic card so you can use GPU acceleration for those plugins that can use it. One of my dozen laptops is a Lenovo T430 that has two graphic cards, one of which is a reasonably decent nVidia that I can switch to when needed. With that laptop I also purchased an extra battery "slice" that, when installed, significantly increases run time. I can get 14-18 hours without any problem, and can get 7+ hours even with all the settings turned up to maximum performance. It is a little heavy, but that doesn't bother me, even when traveling, and I don't think it would be enough weight to lower your boat.