Nvidia Optimus: Switchable Graphics done right?
Nvidia presents Optimus: The technology allows notebooks to switch the GPU themselves. Gaming with a Geforce, web surfing with an Intel GMA X4500HD - and the user doesn't have to care about it. PC Games hardware summarizes the information for you.
Nvidia's Optimus is an evolution of Switchable Graphics. This technology allowed notebook users to switch between the integrated graphics unit (IGP) and a dedicated Geforce mobile GPU as it has been necessary. But like every spadework Switchable Graphics suffered from some restrictions: First of all the user had to switch GPU manually, by pressing a button. Secondly this process took some seconds where the display was flickering and it could even be necessary to reboot the system. Furthermore the complex circuitry was comparatively expensive. All that is supposed to be gone with Optimus.
According to Nvidia Optimus isn't just software, but also requires additional hardware. The target for Optimus is clearly defined: Simple tasks like web surfing or writing texts are supposed to be dealt with by the IGP in order to increase the operational time. But as soon as the user runs a game the dedicated Geforce M is activated automatically - without a delay. If the gamer closes the game again and goes back to the desktop the IGP is back in charge. The Geforce and the PCI Express connection are deactivated completely.
Both graphics chips, IGP and GPU are usually working parallel. Thus it is necessary to have a driver for both of them. This is imposes another restriction: Windows 7 is required for Optimus since Microsoft latest operating system supports multiple graphics drivers simultaneously - Vista for example doesn't.
Nvidia has also created a Q&A that covers several of the important facts of the Optimus technology. You can find a quote of the document below.
General
Q: What are you announcing today?
A: NVIDIA is announcing a new technology for notebooks called Optimus that optimizes the mobile experience by letting the user get the performance of discrete graphics from a notebook while still delivering great battery life. Optimus accomplishes this by automatically and seamlessly selecting the right graphics processor for the job between an NVIDIA discrete GPU or an Intel integrated GPU.
Q: Why is it significant?
A: In the past, consumers were forced to prioritize performance or battery life, as one feature typically suffers significantly in order to accommodate the other. That would make maximum battery life one of the barriers to GPU adoption in notebooks, and Optimus removes that barrier.
Older technology called Switchable Graphics helped address this but there were still several issues. Optimus is different and is able to automatically give users the performance they need while also maximizing battery life, transparently, and with zero effort. It just works.
Optimus is automatic. With certain types of applications the Optimus technology determines whether it should be run on the integrated graphics or discrete graphics. Others require an Optimus profile, which identifies whether the application can benefit from the added horsepower of the GPU. Optimus determines the best processor for the workload and routs it accordingly.
Technical
Q: What is the difference between switchable graphics and Optimus?
A: Switchable graphics is a technology pioneered by NVIDIA and introduced about 2 years ago. With switchable graphics, users have the advantage of having access to discrete and integrated graphics. However, they are required to manually switch between the two. Switching also often requires shutting down applications that are running and sometimes requires rebooting the system. Also, with Switchable Graphics often users do not know or remember what state their notebook is in. The result: users get frustrated and rarely switch.
Optimus is automatic and transparent to the end user. Users simply launch their desired application(s) and the technology figures the best processor to do the job.
Q: Which GPUs will Optimus support?
A: GeForce 200M series, GeForce 300M series, next-gen GeForce M, and next-gen ION GPUs all support Optimus.
Q: Is there a manual feature?
A: Yes, if you'd like to decide which graphics run an application you can edit the Optimus Profile in the NVIDIA Control Panel, or right click on the application and select the GPU you prefer.
Q: Will the end user see two graphic subsystems, each with its own Control Panel?
A: Yes, two graphics adapters are visible, each with its own control panel. This gives the end user the ability to tune each graphics capability if desired.
Q: Has Intel been involved in co-developing Optimus with NVIDIA?
A: Optimus is an NVIDIA technology that uses standard industry busses and interfaces. Intel is not directly involved with the development of Optimus.
Q: Is there a performance impact from outputting to Intel's integrated graphics instead of the discrete GPU's own header?
A: No, there is no performance impact.
Q: Will the discrete GPU power-on when you invoke a web browser like Internet Explorer or FireFox?
A: Not unless the discrete GPU is needed, to play Flash video for instance. Then the discrete GPU will be turned on. Otherwise it will use integrated graphics.
Q: What operating systems does Optimus require?
A: Optimus requires Windows 7.
Q: What notebook CPUs support Optimus?
A: Intel Penryn (Core 2 Duo), Intel Arrandale (Core i Family), Intel Pine Trail (Atom N4xx).
Business
Q: What OEMs are making announcements of systems based on Optimus?
A: Notebooks with NVIDIA Optimus technology will be available shortly, starting with the Asus UL50Vf notebook, and followed by several ASUS Arrandale notebooks (N61Jv, N71Jv, N82Jv, U30Jc). More OEM announcements will follow.
Q: Will Optimus support next-generation ION?
A: Yes.
Q: When will NVIDIA introduce next-generation ION GPUs?
A: Later this quarter (Q1, 2010).
