Is it possible to switch between integrated and dedicated graphics on a desktop?

[f4phantom2500]

Title pretty much says it all. I have an AMD 785G chipset and a Radeon 4870 installed. I would like to be able to switch to the integrated graphics whenever I'm not gaming, even if it would require a system restart I would be fine with that, as long as I wouldn't have to physically uninstall/reinstall the video card every time. I'm mainly concerned with the power and heat issues of a 4870, even at idle it's a hungry beast. I know there are laptops that do something like this, so is it possible for a desktop?

 

[SonicIce]

might be able to install both then disable the one you don't want in device manager

 

[Sylvanas]

Last I remeber, Hybrid Crossfire is only available in conjunction with 4250, 3450 and other low end cards. So I'd say you are out of luck. Disabling the driver will not power down the card, but these cards idle reletively low anyway.

 

[f4phantom2500]

Last I remeber, Hybrid Crossfire is only available in conjunction with 4250, 3450 and other low end cards. So I'd say you are out of luck. Disabling the driver will not power down the card, but these cards idle reletively low anyway.

If I'm not mistaken, doesn't Hybrid Crossfire specifically refer to using both GPUs in conjunction with each other? That's not what I want to do; I only want to be able to dynamically switch between the two.

As a side note, I had a brain lapse when I wrote the OP. I have a 4870, not a 4850.

http://ixbtlabs.com/articles3/mainboard/roundup-785g-p2.html

Scroll down to the section labeled "Enclosure Power Consumption". The Asus board listed in those charts is the exact motherboard I have. As you can see, even a 4850 at idle more than doubles the total system power consumption over using the IGP. Granted, that setup is a little different from mine, I'm running an Athlon II X3, 2 Caviar Green hard drives, and Windows 7 64, but you get the idea.

Besides, I live in Texas, and my room is hot enough already without the space heater that is the 4870 running all the time.

 

[ViRGE]

For what you want to do, no. So long as the 4870 is plugged in, it's going to go in to at least an idle state. It's not a GPU with "switchable" circuitry that allows it to be powered down while plugged in.

 

[f4phantom2500]

For what you want to do, no. So long as the 4870 is plugged in, it's going to go in to at least an idle state. It's not a GPU with "switchable" circuitry that allows it to be powered down while plugged in.

Dang, I figured that was the case but it's still disappointing. I mean, laptops with both discrete and integrated GPUs have been able to do this for awhile now (granted that is a laptop and power consumption is a much more pressing issue in that application), you'd think it wouldn't take much effort to bring this technology to the desktop.

 

[ViRGE]

Dang, I figured that was the case but it's still disappointing. I mean, laptops with both discrete and integrated GPUs have been able to do this for awhile now (granted that is a laptop and power consumption is a much more pressing issue in that application), you'd think it wouldn't take much effort to bring this technology to the desktop.

You would have to build the tech in to the motherboard (cost++) and for AMD GPUs it would require a matching IGP. One of these days you may see NV make Optimus available for desktops, but even that seems unlikely right now. Switchable desktop GPUs seemed to die out with NVIDIA's chipset business (they were at one point scheduled to make all chipsets IGPs, and all GPUs support just this).

 

[tweakboy]

You can't make a BIOS change through software my friend. Forget about it, or wait until the Dual GPU one pcb nvidia comes out. 490 GTX or 500 GTX, not shure on the naming structure... thx

 

[LoneNinja]

I know in my bios I can choose to disable the dedicated card and use integrated upon start up, and windows is good about reloading the right driver, but I would assume the dedicated card is still consuming idle power. I only did it a few times to test the performance difference between the onboard 3300 and a 3650 about a year ago.

 

[f4phantom2500]

I know in my bios I can choose to disable the dedicated card and use integrated upon start up, and windows is good about reloading the right driver, but I would assume the dedicated card is still consuming idle power. I only did it a few times to test the performance difference between the onboard 3300 and a 3650 about a year ago.

I thought about doing something like that, but I think you're right. That being said, the 785G integrated GPU is a 4200, which if I'm not mistaken is fundamentally the same as the integrated GPU that you're referring to, which uses the same driver as my 4870.


As a side note, now that I think about it even if I could figure out how to power down the dedicated GPU, I would have the problem of switching outputs. In a laptop this isn't a problem as the interoperation of an integrated GPU alongside a discrete GPU is still integrated into the platform, and consequently a laptop has a dynamic video output. That is to say, both chips output via the same channel. So if you're outputting to the laptop screen, either one automatically sends video signal to the laptop screen. If you're plugged into an external monitor, I believe that either GPU would output from that same port.

I'm not sure if you had that problem, LoneNinja, but also I'm pretty sure the 3650 is compatible with Hybrid Crossfire, which means that it's at least possible for both GPUs to use the same video output.

 

[NoQuarter]

Depending on the inputs your monitor supports you could hook the HDMI to your 4870 and DVI to your motherboard and set it to autodetect so when you disabled one or the other the monitor still picks up the signal from the other. But it definitely doesn't matter, even disabled the 4870 is going to be in idle state.

I don't know how low the 4870 clocks for idle speeds btw.. it may be possible to clock it lower using Rivatuner to save some power though.

 

[f4phantom2500]

Depending on the inputs your monitor supports you could hook the HDMI to your 4870 and DVI to your motherboard and set it to autodetect so when you disabled one or the other the monitor still picks up the signal from the other. But it definitely doesn't matter, even disabled the 4870 is going to be in idle state.

I don't know how low the 4870 clocks for idle speeds btw.. it may be possible to clock it lower using Rivatuner to save some power though.

My monitor has 3 inputs. 1 VGA, 1 DVI, and 1 HDMI. However, they're all being used; I have my 4870 connected via DVI, my Xbox 360 connected via VGA, and my Verizon FIOS HD box connected via HDMI. So I would also have to deal with that little inconvenience as well. However it wouldn't be too much of a hassle to manually plug in the corresponding video card, as I don't game too much and that is much less involved than physically uninstalling and reinstalling the 4870 based on my usage. Mainly I don't want to risk frying it with static. That has only happened to me once ever, with a Ti4200 years ago, and I am more cautious now, but it only takes once. As a side note, the multi-device setup works out very well because I have a set of Logitech Z-5500, which has my computer's X-Fi connected via the Green/Black/Orange cables, 360 hooked up via S/PDIF optical, and FIOS box hooked up via S/PDIF coaxial.

Regarding idle clocks for the 4870, I know it goes at least as low as 500/500, but it's a relatively moot point, unless I set up a profile for it to undervolt it's still going to use a lot of power and I'd might as well not run the integrated GPU as such.