NVIDIA Optimus Technology: Performance and Battery Life for your Notebook

Battery Life and Performance Testing

It should be clear to you now that NVIDIA’s Optimus technology is pretty impressive both on paper and in our week of spending real-world testing time with it.  Of course, while we can say we love the technology based on those facts alone, we of course needed to test it and see how it performed in a couple of key areas: battery life testing and performance testing. 

Battery life testing is important because the promise of NVIDIA Optimus is that we would get all the performance benefits of having a discrete GPU in our notebook without losing the advantages in battery life of using an integrated graphics solution.  To test this claim we had a pair of identically configured ASUS UL50 notebooks running side by side:

• ASUS UL50
• Intel U7300 ULV CPU @ 1.3 GHz
• 4GB DDR3 Memory
• NVIDIA GeForce G210M 512MB
• Mobile Intel 4-series Express Chipset Graphics
• Seagate 320GB 5400 RPM HDD
• 1366×768 display
• Windows 7 Ultimate x64

The only difference of course was that while one ASUS UL50 had Optimus technology enabled, the other did not; they were otherwise identical to make for a perfect comparison.  We tested the UL50 with Optimus technology against the UL50 without it in both GPU enabled and GPU disabled configurations so we could see how users in both methods would differ.  This helps us to compare user experiences that are exactly the same – no switching back and forth between modes for us!

The battery test was the same PCPer Web Browsing Battery Test we have used in our recent notebook reviews that mixes in some YouTube video playback with basic web browsing to facilitate a real-world scenario.  The test is looped with a timer keeping track of elapsed time in the background.  WiFi was enabled and working while the displays were set to a 50% output.


The UL50 with Optimus technology was the battery life leader coming in at 5 hours and 34 minutes of total couch surfing time.  The same UL50 with the IGP powering the system was able to nearly match it with 5 hours and 26 minutes.  To be clear, with the IGP running on the UL50 even HD YouTube videos seemed to playback relatively well with a few other tabs open.  It was only when we really pushed the system by playing back a pair of 1080p YouTube videos that we saw noticeable frame drop on the IGP-only configuration.  That does not mean that the IGP-only UL50 was in the clear – a user that is taxing the system more would likely see considerably higher CPU utilization than they would if a GPU was enabled (either with Optimus or full-time enabled with switchable graphics. 

Here is what is important to me though: the UL50 with switchable graphics with the GPU enabled had greater than hour LESS battery life running the same battery test.  This means that if you, as a user, decided you wanted the best possible computing experience and left the GPU enabled on the switchable system, you would be losing out on about 30% of your total available battery life when compared to the Optimus-enabled system. 

That is a huge difference: the Optimus system had 30% better battery life compared to a system with switchable graphics enabled and nearly identical battery life to a system with switchable graphics disabled. 

With the battery life question decided let’s take a look at how a couple of our gaming tests compared among the same three systems – would the graphics performance be affected at all by the Optimus technology and the hardware/software changes necessary to make it work?


It is quite clear that the graphics performance between the Optimus system and the switchable system with the discrete NVIDIA GPU enabled was identical.  The GPU obviously did not lose any of its power because of the Copy Engine or Routing Layer implementations.  What is noticeable is the severe lack of gaming power from the Intel IGP – 6 frames per second at 1366×768 on Medium settings?  Ugh.

And just to prove that Flash video CAN benefit even non-Atom based systems, see this example of a pair of YouTube streams working without stutter on the Optimus-based system but having extremely noticeable stuttering issues on the IGP-enabled switchable system.