Slashdot Mirror
Energy Efficient Graphics Processors?
An anonymous reader asks: "The trends for graphics hardware these days seems to be to draw more power and create more heat to get faster processors and push more polygons. Yet in the CPU arena chips like the Via C3 and Epia, Transmeta Crusoe and Astro, Intel Pentium M, and IBM/Motorola PowerPC (G3-5) seem to favor more power per megahertz and cooler runnings without significant performance loss. Is this just because of the nature of the CPU versus GPU? I understand a GPU die is almost entirely reserved for calculation while the CPU is only 20% of so for calculation. Or are the graphics chip makers merely refusing to innovate and take routes that would reign in out of control energy consumption because of the race for more polygons? What kind of architectural changes could be implemented to alleviate graphics card power gluttony?"
The latest Pentiums are power hungry hogs too, if you want the latest and greatest it's going to be less effienct than it could be. Low power consumption, size of heat sinks, volume of fans are less of a design constraint that the raw power of the chip.
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
Sure, we can put a full foot of copper on our CPU's, but everybody screams and moans when Nvidia builds a cooler that takes up the adjoining PCI slot. Graphics cards are limited with the space they can take up for their cooling solutions, and they certainly pay for that in heat generation.
Most versions of the Geforce FX 5200 (non-Ultra) run fanless, which should speak to its relative energy efficiency. It also runs about as fast as a Geforce 3, unfortunately.
For great justice.
Since when is the G5 efficient? It is as hot as any of the others. The G4 is a cool processor, but it runs at speeds like 1 GHz. Not that it doesn't make an awesome laptop (I've never had a complaint about mine) but it isn't exactly a model of efficiency.
You've compared high-end 3d desktop gamer cards which are excessive on heat and power to CPU chips which are designed for lower power low heat situations. The difference isn't nearly as pronounced with a more valid comparison on the CPU side, say a high end P4EE or Athlon64/Opteron. Also as you've stated, the GPUs are almost entirely dedicated to high-power processing, whereas the CPUs spend a lot of their silicon on other things. A high end GPU is generally superior to a high end CPU in terms of raw computing power. Therefore, it needs more power and makes more heat. If you forced intel or amd to build a CPU for you right now that had the raw compute potential of the latest high end cards, they'd have a hard time doing so without being just as hot and power hungry. All these things scale over time, but the demands of the user and his software scale up to meet it as well.
11*43+456^2
No, but the GPU's he's talking about would fall into the same category as the P4's, which was my point..
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
As gamer laptops get more popular, shouldn't we see new lower power GPUs with comparable muscle to the previous rev?
What's the power consumption like on a GPU that isn't doing much? Do they sleep like some CPUs can, or are they always going at full bore?
A few seconds on Google and I found nVidia's mobile offering. A few more seconds and I found this. Undoubtedly ATI has something similar.
I introduce this document as reference.
According to this, a PowerPC 970FX (the G5's being used in Apple's Xserves and the chip that will be in Apple's desktops this year) uses ~24.5W at 2.0ghz. So two of these are still only using half the wattage of a single Prescott chip, and obviously they can perform, too.
So yes, many of the chips he mentioned are not performance oriented, but the PowerPC 970FX certainly is, and it's safe to say it has made huge headway in power efficiency.
The biggest reason heat output keeps going up is that these gains only provide incremental benefits. To truly leverage the design changes, you have to run it as fast as it'll go ---> lots of heat.
The PowerPC isn't anything to scoff at, but if anyone could easily bump up the voltage & the multipliers, I'm sure a new G5 could be used to heat up your room in the winter.... and btw- Heat output does not increase linearly. The newer ATIs come with stock GPU & RAM voltages around 1.7 & 2.9. Unlike AMD/Intel/Nvidia/ATI *PUs, mac's aren't easily overclockable and when they are OCed they have very fine tolerances. Maybe if the powerpc chip put out a little more heat it could go faster?
[Fuck Beta]
o0t!
I tried a no-name GeForce 4 MX440 a couple of years back, but the display quality was awful. It was so poor I had to downgrade to 1280x1024 on my 19" Trinitron screen. After a few months the card broke and I went back to my TNT2 Ultra (Creative Labs) and back up to 1600x1200.
I was thinking about getting something fanless and by nVidia since their (binary-only) drivers are superb on Linux (I don't do the idealogical zealotry as much nowadays).
High-performance 3D is nice when you need it, but nowadays stuff is so powerful for under $100 that there's not much point to buying something really expensive. Some of us want a crisp, high-resolution display, flicker-free (70Hz+) without a great big noisy fan.
Stick Men
3 words : Tile Based Rendering
PowerVR used to make a GPU with the transistor count of a Voodoo 2 card, but with the power of GeForces 2 of its time.
These days, they are using this technology to build very low powered GPU for embed systems.
But they announced that they will soone start again to build GPU for SEGA's arcade systems.
Let's just hope they'll soon built a PC derivative of this arcade GPU.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]