AMD has claimed great power savings with the 785G chipset and its Powerplay feature. Let's see how the platforms compare:

Now this test isn't an ideal way to compare the 785G to the 780G, as we only have a 790GX board on hand and underclocked it to simulate the 780G specifications for this test. However, the power draw difference is so slight between the 785G and simulated 780G that we doubt there'd be much of a difference with an actual 780G board.
Comparing platforms, it looks like the E7200 CPU on the Intel LGA 775-based boards uses less power than the Phenom II X2 550, which is no surprise, as the Phenom II X2 is a much faster CPU with a lot more cache. The Athlon II X2 250, however, sips even less load power than the Core 2 Duo E7200.
Analysis
Now, I'm all for environmental friendliness, but all too often I think the bottom line cost for an end-user is overlooked. So let's examine the power savings of the E7200 over the Phenom II X2 550.
At idle, the Phenom II X2 is drawing the highest load: 92 W on the 790GX motherboard. In contrast, the E7200 is drawing 66 W on the most efficient platform, Intel's G45. It looks big on the chart, but it's a difference of 26 W.
In the most populated coastal cities of the United States, electricity costs are the highest in the country at about 15 cents per kilowatt/hour. With this information, we can calculate the cost to use the Phenom II X2 550 compared to the Core 2 Duo E7200.
Let's compare the worst-case scenario, a PC with a Phenom II X2 550 and a 790GX motherboard, to the best-case scenario, a machine with a Core 2 Duo E7200 paired with a G45 motherboard. If you left a Phenom II X2 550/790GX-equipped PC in active idle state for 24 hours a day, you would be billed $34.16 more compared to the E7200/G45 in electricity costs every calendar year, and that's assuming you leave your computer on in an active state and don't turn it off or let it enter sleep mode.
This equates to big numbers for massive corporations deploying thousands of PCs, but for the home user it shouldn't be as much of a concern. In a home environment, I'd recommend the faster processor so that the performance is there when you need it. As for environmental concerns, Mother Earth is far better served by simply turning your PC off when it isn't being used.
There are two lessons to be learned here: first, if you really care about the environment, turn your PC off (or at least configure it to enter sleep mode) when you're not using it, and second, don't be afraid of purchasing a better processor for fear that it will cost you big money in power consumption.
- Introduction
- 785G Northbridge And SB710 Southbridge Vital Statistics
- Features For The Home-Theater Crowd
- Radeon HD 4200 Enhancements
- Other 785G Goodies
- Hardware Choices, Setup, And Overclocking
- Test System And Benchmarks
- Benchmark Results: Synthetics
- Benchmark Results: Audio And Video Encoding
- Benchmark Results: 3D Rendering And Productivity
- Game Benchmarks: First-Person Shooters
- Game Benchmarks: Flight Sim And RTS
- HD Video Playback Benchmarks
- GPGPU Benchmark
- Power Usage Benchmark
- Conclusion
A integrated GPU that can game. =D
Makes my lil Pentium D with a 4670 seem puny...
3.3GB/s memory bandwidth (single channel DDR2 533... though 2 sticks, it runs in single channel... damn prebuilts) also seems sad on my rig...
Good question. A dual core Atom with a 4200 integrated would be nice.
We all know Intel makes shitty mothebroards and AMD makes kickass motherboards anyways.
Not correct, the P2 has a built in memory controller so the switch to ddr3 affected that controller
Native ram for a pentium d is PC4200 which has a max of 4.2gb/s per channel etc and the FSB has the max of 6.4gb/s
The Intel atom would most likely underpower any video card out there, and Intel does actually make a good reliable business platform where video performance is not required etc
Perhaps the next task could be a power comparison to tell us how long a computer needs to stand in active state to consume more power than turning it off and back on again (including starting msn,av software and a bunch of other stuff running in the background).
Anyway good article
PS: Phenom II does support DDR3, there are only 2 models out of 12 that don't...
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My take on it is except for some specific HTPC features, the 790GX is still the better of the two, especially if any gaming is involved. They compared an OC'ed 785G to a stock 790GX; what if they'd OC'ed the 790GX also?
And, lest anyone develop any false hope, the Intel IGP has once again been shown to be a toad.
Let's seee... Decent performance, able to play HD videos, low cost. That covers everything I need for a HTPC!
We concentrated on the new aspects of the 785G in this article; hybrid crossfire is exactly the same as it was with the 780G, that is to say it maxes out with a 3450 card.
Nope, it's using a 24 W difference. I think that's why your numbers are different too. I get:
24 Watts * 24 hours = 576 WHrs / 1000 W/KW = .576 KWHrs * $0.15 cents/KWHr * 365 days = $31.54
Good article otherwise, thanks.
That is incorrect, if that was the case, the Phenom II wouldn't benchmark so much better and it wouldn't overclock so much better. Just because it has the Phenom name to it, doesn't mean all they did was give it a bit more L3 Cache and call it a day. You could've given the original Phenom more L3 cache all day long and it wouldn't still ran like poop. Not necessarily poop, but just not as well as the Phenom II.
If this is true, then why does the Hybrid crossfire graphic on the first page show HD4350, HD4550 and HD4650 as compatible hybrid crossfire GPUs?
It makes sense.. the 780G used an integrated 3200-series GPU, so it was compatible with lower-end dedicated 3000-series GPUs. The 785G uses an integrated 4200-series GPU, so it should be compatible with the lower-end dedicated 4000-series GPUs.
Can you clear this up? I was also wondering what GPU's can be used as Hybrid crossfire with the 785G. I thought I knew from that graphic on page 1, but your response confused me.
Thanks
Thanks for clearing it out, Cleeve! There is not much sense using Hybrid CF then. However, my original question still remains: how much extra wattage may one expect with mid-range 4600 or 4700 card added for example? Does disabling the device help here a bit more when not in use? Hope this is not too off-topic already...