Impressive GPU Numbers From Folding@Home 201
ludd1t3 writes, "The Folding@Home project has put forth some impressive performance numbers with the GPU client that's designed to work with the ATI X1900. According to the client statistics, there are 448 registered GPUs that produce 29 TFLOPS. Those 448 GPUs outperform the combined 25,050 CPUs registered by the Linux and Mac OS clients. Ouch! Are ASICs really that much better than general-purpose circuits? If so, does that mean that IBM was right all along with their AS/400, iSeries product which makes heavy use of ASICs?"
Re:Lopsided Alright.. (Score:4, Insightful)
Obvious? (Score:2, Insightful)
Maybe I'm missing some subtlety in the OP somewhere, but if GPUs weren't better at what they're doing than CPUs, there wouldn't be a point in having a GPU in the first place.
...and if you have a problem that can be expressed in terms of the problem space the GPU is designed to handle, then that problem is going to run faster on the gpu than on the CPU.
GPUs are Specialized Parallel Computers (Score:5, Insightful)
Making a general purpose parallel computer is very, very hard. It just so happens that you can use things like shaders for more than just graphics processing, and so via OpenGL and DirectX you can make GPUs do some nifty things.
In theory, and indeed often in practice, parallel computers are much, much faster than their serial counterparts. Hence the reason a GPU that costs $200 can render incredible 3D scenes that a $1000 CPU wouldn't have a prayer trying to render.
Re:This is the perfect time... (Score:5, Insightful)
Using your CPU as a space heater is not a bad idea. It is 100% efficient. Every watt it consumes gets turned into heat. Before someone says "but the cooling fans are wasteful" let me remind you that the air moved by those cooling fans will eventually come to a stop (inside your house) as a result of friction, releasing its energy as heat in the process.
Depending on what type of space heater you use, and the construction of your house, your computer can be more efficient than many other electric space heaters. Since none of the energy "consumed" by your CPU/GPU is converted to visible light, none of it has the opportunity to leave your house through your window panes (assuming you have IR reflective glass). Contrast this to quartz and halogen space heaters which produce a fair amount of visible light.
In much the same way, incandescent bulbs match the efficiency of compact fluorescents during the winter months. Every watt "wasted" as heat during the summer is now performing useful work heating your house. (Before someone says "you called a quartz/halogen space heater inefficient because of its waste light, and now an incandescent efficient because of its waste heat!' let me say that the space heater's light is not useful light, while the bulb's heat is useful heat (during the cool months.))
Re: Are ASICs really that much better? (Score:4, Insightful)
Not a mystery (Score:3, Insightful)
Now, offer them a GPU-driven alternative. For the most part, the only people that will install and run it are those with a fancy-schmancy video card capable of running it, and for the most part, the only people that have a fancy-schmancy video card capable of running it have high-performance computers as well (or at least more recent computers that came with compatible cards.)
So let's say that's ten out of the hundred, and those ten are statistically likely to have had the highest-performing CPUs as well; so you've pulled the top ten performers out of the CPU-client pool, and thrown them in the GPU-client pool. Even if you didn't switch those ten people over to the GPU, you could probably isolate those computers' CPU-client performance numbers from the other 90 and find that they're disproportionally faster than a larger number of the slower computers.
There's still more to the story, of course, but you really are taking the highest-performing computers out of the CPU pool and into the GPU pool. The exception would be high-performance servers with lousy/no graphic cards, but those are likely working so hard to perform their normal business that Folding@Home isn't a priority.
Re:This is the perfect time... (Score:3, Insightful)
I am spending $.10 for the extra kw hour roughly. In the summer I waste money on AC in the winter I save
gas money on heat. If I put my computer in 4watt S3 standby for 15 of those 20 hours, I can save a lot more.
FAH calculations do not depend on "free" "idle" computer power, they depend on users spending money to generate
the results.
Re:This is the perfect time... (Score:4, Insightful)
Natural gas is (cdn)$0.278287 per cubic meter, and electricity is 0.058
At 96% efficiency, natural gas works out to 0.027331 / kwh, (3413 btu in 1 kwh) or 47% of the cost of electricity at today's prices in Toronto.
So 1/3 was a bit of hyperbole, but not too much.
Re:Not a mystery (Score:5, Insightful)
500 users out of 25000 means that you have at most taken the 2 percent highest performers out of the CPU pool. If we assume that those 2 percent have computers that are 5 times as powerful as the average computer, then we have lowered the average performance of the CPU pool by roughly 9%.
This 9% systematic effect will lower the reported performance superiority of around 5000% of the GPU vs. the CPU to something like 4500%. I.e. it doesnt change the result at all (which seems to be that GPUs kick ass for these applications).
Re:Lopsided Alright.. (Score:5, Insightful)
Not really. (Score:4, Insightful)
>Using your CPU as a space heater is not a bad idea. It is 100% efficient.
Not really. Consider exergy [wikipedia.org]. Yes, your CPU is just as efficient as any electric space heater. However, consider that the alternative is probably burning natural gas or oil in a furnace. If you burn fuel for heat, 90%+ of the chemical energy goes to producing heat (the rest is lost as unburnt hydrocarbons in the exhaust). If you burn fuel to spin a turbine at a power plant, only about 40% goes to electrical energy, and unless it's a cogeneration plant which uses the waste heat for industrial purposes, the rest is lost as heat up the smokestacks. So, starting from the fossil-fuel source, electrical heating is less than half as efficient as burning fuel for heat. If you do need to heat using electric power, it's much more efficient to use that electricity to pump heat in from a lower temperature outside than it is to turn that electricity itself into heat.
If you are stuck with electric (non-heat-pump) heating in your house, however, you are correct: There is absolutely no reason not to run your CPU or any other electrical appliance full tilt.
Re:Distributed amongst home users (Score:3, Insightful)