101–110 of 174 posts
This is pretty cool from a low powered 144 computer chip. http://www.greenarraychips.com/
Not really. It's expensive, a dick to program, no FP support and single thread performance is rubbish. A cheap ARM is a better deal now and they are quoted in uA/MHz for performance so you can trade off your performance on the fly.
This isn't even bro science!
Earlier quoted context omitted.
My laptop is far from modern. It also has to power an old screen.
200W still seems really high. A +10yo MacBook Pro used an 85W charger, and it rarely if ever reached that max. I find it hard to believe that even an old gaming laptop would require over twice that.
2 years, 2 generations before to Sandy Bridge: Core 2 Quad Q9000 (Q1 2009) -> i7 2820QM (Q1 2011) = +100%
Sandy Bridge to 6 generations later, 6.5 years later: i7 2820QM (Q1 2011) -> i7 8550U (Q3 2017) = +37%
Yes, I'm mixing tick-tock cycles or low voltage with "standard versions". So let's see a more appropriate competitor:
Sandy Bridge to 5 generations later, 6 years later: i7 2820QM (Q1 2011) -> i7 7820HQ (Q1 2017) = +50 %
So we had processors that doubled the performance in 2 years (and more than double if we disregard not-so-common Core Quads and take often only two-core mobile processors). Yet, 6 years later, there was only a 50 % increase. Until Ryzen came recently and made Intel to quickly come with Skylake-X, i9s and FINALLY, OH FINALLY, 6 (powerful) cores in laptops, there was no real performance reasons to upgrade, only for heat or thickness, those went down, performance didn't went up so much.
So, around that 2011, those were that crazy times, when you could have:
45 W or 55 W CPU (i7 2820QM or 2920XM)
55 W GPU (Quadro 2000m)
two SATA drives
four DIMM modules
In a non-gaming, back then "standard" size laptop (ThinkPad W520). And under heavy load, anything under Tjunction (say, 95 °C) was good enough. Some laptops with only a single 55 W dissipating fan (such as the ThinkPad W520) often throttled under full CPU and GPU load and couldn't run Turbo with full GPU load, others (such as Dell Precision M6600) had two separate fans and some even came with Quadro 4000m GPU with a TDP of... 100 watts!
So, back then, those laptops ordinarily came with 170+ W power supplies (even over 200 W) and just a CPU+GPU could draw well over 100 W (add the rest of the systems, hard drive here, hard drive there, all four DIMM slots populated, charging the battery) and it would easily go over the twice of that 10 year old laptop with 85 W charger.
And these are workstation models. If you mention gaming laptops, those sometimes had desktop CPUs in them and required 300 W PSUs. Nowadays they also use desktop GPUs and require TWO 300 W PSUs...
Please, don't base observations on 10-year old Tick (probably Penryn?) with 85 W chargers, when 7-8 years ago, a Tock (Sandy Bridge) came with literal concrete bricks as power supplies and really pulled 200 watts. Thankfully, things got dialed back after that, but at the cost of performance until now and current mobile 6-core i9s and Xeons.
And to the lap comments - you really didn't want to have those laptops in your lap when they were plugged in and turbo-ing...
Earlier quoted context omitted.
>So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. This comparison doesn't make a lot of sense to me. It's not even comparing apples to oranges, it's comparing apples to the concept of taste. Furthermore these percentages don't really tell you much regarding efficiency, I'm sure there are less developed societies where computers count for less than 5% of all energy consu…
Why not, though? Energy is energy -- we (humans) oxidize food, basically burning it slowly, to power our bodies. Whether the energy is carried by glucose/ATP or electric current is just an implementation detail. Comparisons are frequently made in other domains as well -- e.g., cyclists measure power outputs in watts. The rule of thumb I've understood is that the brain runs on about 20 watts (peak power), and a human…
If you wanted to compare them, cite the percent that the CPU uses of its PSU, or cite the percent that human brains use of global energy consumption. Otherwise they're completely different things that have no meaning in relation to each other.
> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
It would make more sense to compare absolute numbers. A brain uses about 20W. A modern computer has similar consumption, but is many orders of magnitude less powerful.
Our brains are highly specialized, you’re comparing an ASIC strapped to a Z80 with modern general purpose CPU’s.
> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
It would make more sense to compare absolute numbers. A brain uses about 20W. A modern computer has similar consumption, but is many orders of magnitude less powerful.
> Why Do Computers Use So Much Energy? Ads.
Earlier quoted context omitted.
Power consumption is more or less square to per-thread throughput. Power consumption is between square and m^n to inter-core bandwidth and count. So, a high-end smartphone CPU might do 1/5th of the throughput of a desktop CPU using 1/25th of the power.
Those formulas seem highly unlikely to me. Power consumption is generally proportional to clock speed. And I don't know what m^n even means in this context.
Just guessing here, by pulling apart what little is in there:
* Total power usage has a big fixed parts, e.g. screen power usage going up linear with brightness and screen size. Or RAM power usage goes up linearly per bit just to keep the memory intact. So Let's assume OP talks about only the 'clocked' components, like CPUs and busses.
* I did hear for single core CPUs how the power usage arose with the square of the CPU speed, unless offset by die shrinking or technological advances. This was one of nature's walls hit by the Pentium IV. Can't find a good reference atm, but here http://www.tomshardware.co.uk/answers/id-3025075/higher-cloc... is a page with the first graph looking square-ish being what happens with power usage when clock goes up on the same machine.
* And throughput is linear with clock speed, if nothing else changes. If you double your clock, you double your throughput just by moving more data over the same bus. So the third line of OP is consistent with this: 1/5 of the throughput is reachable with 1/5th of the clock, thus 1/25 of the power.
* First line might compare 2 ways to raise the throughput: Either rise the speed of 1 core or add more cores. When you rise the speed of 1 core, power goes with the square of this rise. When you add more cores, power goes linear with these cores, assuming your interconnect is free.
* Second line 'between square and m^n' needs some interpreting. It might make sense when for a square n=2, and m measures frequency/throughput/core count/... . I assume he says the real relation might be power usage = throughput^2.3 for example
* When you have m cores, and each is interconnected to its m-1 brothers, you have m*(m-1) interconnect elements using power. This is again a square law. You can get around this by not connecting everything to everything, but this will cost you in data throughput - There will be bottlenecks.
Thats what i can make from it.