| Laptops have historically been designed around a | | | | programs that are graphically undemanding the |
| balance of performance and portability. Not only do | | | | NVIDIA graphics chip lies dormant. This means you |
| they need to be capable of handling the tasks they | | | | get the benefits of Dell GK479 battery life and lower |
| are designed for, they need to do so without | | | | heat most of the time. |
| destroying Dell Latitude D630 battery life in the | | | | Where the big difference to previous solutions lies is |
| process. | | | | with graphically intensive applications. When NVIDIA's |
| There are always exceptions to this rule. Big, power | | | | driver detects that the discrete graphics chip is |
| hungry desktop replacements are almost always | | | | needed it powers up the GPU and uses that to |
| designed to be tethered to a power outlet, while | | | | generate the pictures. Unlike previous generations of |
| more portable laptops often lose out in the graphics | | | | hardware Optimus laptops don't have a delay or the |
| department. | | | | need for a reboot for this to happen. |
| Modern graphics chips are usually more complex than | | | | When called upon the GPU in an Optimus laptop will |
| CPUs. This adds not only extra power drain but also | | | | fire up and start rendering. It then puts the output |
| heat issues. This extra heat is actually the reason | | | | images into the IGP's framebuffer. The IGP then |
| why a lot of manufacturers push the term notebook | | | | outputs this picture on the screen. By using the |
| over laptop - having two massively complex chips | | | | integrated graphics hardware in this way NVIDIA not |
| running all the time means that the form factor is not | | | | only manages to get around the tight integration of |
| ideal to use on one's lap. | | | | the IGP but also manages to power up the discrete |
| Trading off between battery and graphical grunt | | | | graphics hardware without the end user noticing. |
| This has led to a quandary. Integrated graphics | | | | This seamless hopping between chips means that |
| hardware is fine for the majority of desktop tasks. It | | | | Optimus powered laptops will have better battery life |
| is also a lot less complex, which means it can run at | | | | than ones using discrete graphics. More importantly |
| lower clock speeds and generates less heat. Throw | | | | though it means that there is much less of a tradeoff |
| on a high definition video, or try and run a 3D game | | | | between portability and power. You will still chew the |
| and integrated graphics struggles. | | | | battery life if you enter into a mammoth Battlefield 2 |
| On the flipside, a GPU is overkill for most day to day | | | | session, but you'll be able to finish working and throw |
| tasks. Web surfing and PowerPoint presentations | | | | on a HD movie without having needlessly burned |
| aren't graphically intensive, and using a discrete GPU | | | | through your Dell GD761 laptop battery life with |
| for this just adds extra power and heat drain to a | | | | spreadsheets. |
| laptop. | | | | How it works in practice |
| There have been many stabs at solutions to this | | | | Of course the promises of this simplicity are grand, |
| over the years. We have seen discrete GPUs used | | | | but oftentimes the implementation is poor. In order |
| instead of integrated graphics, but this only | | | | to get more of a picture of how Optimus works, we |
| exacerbated the problems mentioned above. The | | | | have been playing with an ASUS N61Jv laptop. This is |
| industry then moved towards switchable graphics | | | | the first Optimus products to hit the PC Authority |
| options, where both integrated and discrete graphics | | | | Labs, and pairs the Intel HD graphics IGP on the |
| were built into the laptop. | | | | i5-430M CPU with a Nvidia Geforce GT 325M graphics |
| Historical annoyances | | | | chip. |
| One of the major issues with this was that it | | | | Fire up a graphically intensive application and the |
| required users to hit a function key to switch | | | | laptop runs it without the soul-crushingly low |
| graphics hardware. This would often require a reboot | | | | framerates inherent in Intel integrated graphics. Close |
| to change displays and, like many more obscure | | | | the game and the laptop powers down the NVIDIA |
| features in computing, sometimes users wouldn't | | | | graphics and the IGP takes over all the display |
| even realise the functionality was there. Or for | | | | functions again. |
| convenience sake they'd activate the discrete | | | | It all just works. Which is the massive advantage |
| graphics and just run everything on that, thus | | | | brought by this technology. Unlike previous |
| negating the whole solution. | | | | generations of switchable graphics there is absolutely |
| Even when this technology became driver-switchable | | | | no input required from the end user. Application |
| it didn't actually improve things. There would be an | | | | support comes not only through driver-based |
| inherent delay as a laptop changed output from | | | | autodetection but also through special driver profiles. |
| integrated to discrete graphics and while it was a | | | | These profiles are similar to the ones used for SLI |
| better solution it was still an inelegant one. | | | | support on desktop systems and are automatically |
| Logic dictates that the best solution to this issue | | | | downloaded by the NVIDIA control panel app, |
| would be to just develop a better class of discrete | | | | ensuring ongoing compatibility. |
| graphics that could run in low power situations. This is | | | | Windows 7 laptops only |
| a viable path for AMD, which makes both CPUs and | | | | This brings to bear an interesting thing to keep in |
| GPUs. However for systems using NVIDIA graphics | | | | mind when looking at Optimus products. Because of |
| this has been further complicated by Intel's decision | | | | the reliance on the NVIDIA driver to control when |
| to bolt integrated graphics chips onto its CPU | | | | the discrete graphics powers up, it is essentially a |
| packages. | | | | Windows 7 only technology. Install Linux, Windows |
| This means that NVIDIA has had to adapt if it wants | | | | XP or Vista and the laptop will only access the Intel |
| to keep selling graphics for laptops. This adaptation is | | | | HD graphics IGP - the laptop will still output pictures, |
| known as Optimus technology, and it finally does | | | | but you won't have the option of the pretty graphics |
| away with the arbitrary annoyances seen in previous | | | | delivered by the NVIDIA GPU. |
| generations of switchable graphics. | | | | This will be a moot point for the vast majority of |
| The best of both worlds | | | | users, but something worth remembering if you want |
| Basically what NVIDIA has done is put Intel's IGP to | | | | to diverge from Windows 7. |
| work as a display controller. When you are using | | | | |