Switchable Graphics and the i Series

So far I know that the true quad core i7's do not support switchable graphics but the i5 and i3 processors do.

However this is only if the chipset is an HM5*. However I'm thinking just because a laptop has an i3/i5 and HM5* doesn't mean it will have switchable graphics, am I right? Or is it that that the manufacturer may have not implemented it explicitly and a simple BIOS fix/update/change can enable the IGP that is on the processor? Thanks and sorry if the answer to this was common knowledge

 

At least on the new HP Elitebooks and Lenovo Thinkpads, just because a laptop has a Core i3 or Core i5 (which both have an IGP on chip) does not mean it can support switchable graphics, unfortunately.

And yes, I believe the current Core i7 quad-cores do not have an integrated GPU built in, therefore, they will not support switchable graphics.

 

Switchable graphics is a feature of the chipset... so even though the i3/i5's have GMA HD built in, sometimes it can't be used.

 

That's a shame, would it be possible if the manufacturers released BIOS updates for their computers?

 

I think it would depend on the exact motherboard at that point. I could easily see a manufacturer being lazy and not hooking up the IGP output if they have a discrete GPU running the output.

 

Nvidia Optimus doesn't require any motherboard hardware, however. As such, any computer with IGP and a GeForce 2xxM or 3xxM card ought to be able to support it with the right drivers.

 

According to the discussion in the Asus UL50Vf discussion ( http://forum.notebookreview.com/showthread.php?t=458269, specifically, post #8 and #12) it does require a motherboard change from the usual procedures for switchable graphics, especially since the motherboard will need the appropriate hookups to channel the discrete GPU output into the IGP.

 

Not at all. If you read post #12 from your link, it says

The OCE is located on the GPU, and it transfers data into system memory via the PCI Express bus. No (extra) motherboard hardware required.

From this Anandtech review:

There has been plenty of discussion of Optimus in the N82 thread.

 

lackofcheese, 'OCE' in your post = 'the appropriate hookups to channel the discrete GPU output into the IGP' in Judicator's post.

 

Yes, and as I quite specifically said, the OCE is on the GPU, not the motherboard.

 

Is it on every current generation nVidia GPU?

Anyways, in Optimus systems, the Intel GPU is the one that is always active and in normal systems, the dedicated graphics core is the one that is always active and probably connected straight to the screen.

 

From HotHardware:

So, it's only the 40nm parts, it seems.

 

...but the IGP would have to be connected directly to the screen, not the dedicated GPU as is usual. Unless, all dedicated GPUs are going through the IGP nowadays..

 

That's true.

 

Anyways, don't get me wrong. I'd love to see it work on more laptops.

I've got a first gen Hybrid Power notebook and while I doubt it would ever happen (9600M GT), if a hacked driver came out, I am definitely one of the people who would want to try it out.

 

Since Arrandale already has GMA HD built in, from this point onwards it seems like it would be silly for any Arrandale+Nvidia dGPU laptop not to use the HM55 instead of PM55, and output from the IGP. You're right, though; even if the HM55 board were being used with a dGPU in the normal way you'd have to switch output ports to use Optimus.

The interesting thing is, if you had an IGP system with an empty PCIe slot, you might be able to stick an Nvidia GPU in it and get Optimus to work.

Going back to the original post:

Indeed, if the chipset is PM55 it cannot possibly support switchable graphics. On the other hand, any HM5* motherboard will have all the hardware needed (i.e. video output from the IGP) , but since the graphics output will come from the video card, a simple driver update won't fix this. However, I guess that if the HM55 board were being used, with the output connected from a discrete GPU, you would be able to manually change the screen connection over to the IGP.

 

I believe it was from Intel ARK that stated that the PM55 cannot support switchable graphics. I think right now it's just a matter of drivers and software support as current notebooks w/ the HM55 and a discrete GPU do not support switchable graphics (such as Lenovo T410).

 

There is still the other issue of where on the motherboard the signal is connected. I'm not very sure about how laptop motherboards tend to be set up, but while you'd have to open the laptop, it might just be a matter of changing which port a cable is connected to.

 

If there is such a port for the IGP at all. If manufacturers are cheap enough to take away mini-pci ports and such from netbooks, I don't see why they would implement such a port when one is enough.

 

The thing is, an HM55 board without IGP outputs makes no sense when compared to a PM55 board (the one that doesn't support IGP in the first place). If you're cost-saving by not having anything unnecessary, why have HM55 rather than PM55 in the first place?
More likely, if you're a manufacturer and you end up using an HM55 board for a laptop with discrete graphics (but not switchable graphics), it's because you're using the same board for a range of laptops with and without dGPUs - the mass production might well outweigh your ability to save by customizing the boards.

Sure, this is just conjecture, but I can't see why any manufacturer would make an HM55 board without video outputs.

 

That's what I was thinking too. It doesn't add any extra cost, and it only makes the laptop better.