Nvidia launches dual-GPU tech for notebooks
Hybrid graphics done properly
Nvidia reckons it has finally cracked the problem of smoothly swapping between graphics chips in notebooks that have more than one GPU. Today, it launched its solution, which it has branded Optimus.
Now, we're not talking two or more GPUs configured in SLI mode for greater graphics performance. Optimus addresses the use of a discrete graphics chip that operates when you're running software that needs one, and a separate, integrate graphics core that handles all the other tasks, and does so with a much lower impact on battery life.
This isn't a new notion. To date, there have been plenty of laptops with two GPUs. Originally, they required a physical reboot two switch between them, to allow Windows to load the appropriate driver. That also meant saving work and shutting down applications then reloading them after the restart.
Later, vendors worked out how to flip between the two at the flip of a physical switch. That too required a driver switch, causing the screen to flash and momentarily display garbled pixels while one GPU quit and the other kicked in, but without the need for a full restart.
If the brief blast of screen junk wasn't bad enough, the switching process had to be triggered by the user. You had to decide whether the app you planned to launch would benefit from a full GPU or not, and make the switch accordingly. And then back again when you were done, to ensure your battery wasn't being depleted as quickly.
Few folk, we suspect, bothered to do so, and Nvidia claims its own research shows that just one per cent of dual-GPU laptop owners ever switch between graphics chips.
Mux spreader: the old, sub-optimal approach to hybrid graphics
Nvidia's key promise is that Optimus will do all automatically and behind scenes so that the user doesn't even need to know it's happened.
"It should work like a hybrid car," says Rene Haas, head of Nvidia's notebook GPU operation. Flipping between GPUs should happen as smoothly and as transparently as a hybrid switches between electric and petrol propulsion systems.
COMMENTS
Laptops with 2 GPUs
I'm typing this on such a laptop - a Vaio SZ1VP, which I bought 4 years ago. Run the higher end graphics card when plugged in to power/not on my lap (gets hot)/playing games/need to use DVI connection. Switch to onboard Intel graphics when away from power supply, for MUCH longer laptop life. Works very well, although my laptop require reboot.
Power-saving fail
So instead of running GPU A *or* GPU B, now you run GPU A alone, or GPU A *and* GPU B.
Extra 5% reduction in battery life on FarCry ... just what everybody wanted!
Whole frame buffers flying across the PCIe bus sounds like fun too. But it's OK, no-one was using that bus anyway.
Already done
Some mobile phone multimedia chips use run domains and only switch then on when needed. So there are decode/encode domains, camera ISP domains, 3D domains, mp3 domains, that are only turned on when required. One chip I have knowledge of runs at 500mA, doing all of the above....... I've always wondered why desktop graphics don't do much the same.
Want to make big bucks?
Just make a laptop with a gamer's desk-dock-call-it-whatever-you-like expansion chassis.
Keep the hot, demanding GPU in it, heck, put 2 in. Can even chuck in the big capacious hard disks there.
Here's a wild idea. Maybe even actually have 2 discrete CPUs, one ULV core on the laptop and a grunt heavy lifting one in the chassis, like an i7 or something.
in the mobile form, the actual laptop itself, just the frugal bits, SSD. 8 hour battery life would be good.
Winner.
Do it.
Make it cheap.
I'll buy one.
Laptops with hardware switches to switch GPU's?
Am I the only one here that's never seen or heard of these laptops that had multiple discrete GPU's that use a hardware switch to switch GPU's??? Can somone enlighten me please? Model/Manufacturer? Sounds to me like they are fixing a problem that never existed. Well done.
