If you’re trying to find information on the NVIDIA 9400M Apple is adding to its lower-end MacBooks, here’s a hint: it doesn’t exist. (Not literally, anyway.)

Plain-English summary: NVIDIA’s new graphics card architecture used on the MacBooks combines a chip on the CPU (as found on the old MacBooks) with a dedicated GPU (as found on the MacBook Pros). The dedicated, “discrete” chip is designed for lightweight, power-efficient use, but it should be a boost from the old model. “9400M” applies to both those chips, which have … uh, different numbers. The problem is, no one knows exactly how the combination will perform until they test it; we expect to have more from live visual developers soon.

Updated: Actually, it seems “9400M” on the Mac refers to a new, single-die chip that NVIDIA considers equivalent to their two-chip (discrete + dedicated) combination with the same brand name 9400M. An anonymous reader points us here:
GeForce 9400M G

That last “G” apparently refers to this being a single-chip, motherboard graphics solution. Remove the “G”, and you have a different (though similar), two-chip motherboard + discrete solution. Both seem to have 16 stream processors total, even though the 9400M not on the Mac splits it across two other chips. (Confused yet?) As if it weren’t hard enough to follow whether that “G” is there or not, Apple calls the 9400M G the 9400M. So that means a lot of what I say here refers to the 9400M as on PCs, not the 9400M as on Macs. Ugh.

The information on the site above was added since I first posted this story. Update coming soon, though I’m going to sort my facts first, as this is not exactly Great Moments in Lucid Branding.

Exact details: Yes, as a bizarre twist of branding, the “9400M” is just a brand applied to the combination of two other GPUs. Put a GeForce 9100M G on your motherboard, and add either (bizarrely) a 9300M GS or or 9200M GS as the discrete GPU, and you get a 9400M. What’s the difference between the 9300M and the 9200M (aside from, uh, “100”)? Only the 9300M GS supports hybrid SLI (a technology for combining the two GPUs for better power/performance balance), and Blu-Ray playback.

And that brings us more questions than answers — some questions that are answered for Windows users, but even some questions for them, too (like real-world performance):

  • Will Apple use the 9200M GS or 9300M GS discrete graphics card?
  • Will the Mac support dynamically switching between integrated and discrete graphics to conserve power (as Windows Vista does), or will it do so manually? Updated: Glad I asked. Turns out you’ll have to do it manually; see Engadget video below. That means either Apple isn’t using the 9300M GS that is capable of switching, or they haven’t finished drivers yet, or both. Note that whatever the reason, this could get fixed later on.
  • Will we be able to manually turn on the GPU for live performance? If not, will dynamic switching have an adverse effect on live visual software?
  • What’s real-world performance like?
  • What does this architecture support on the OpenGL side? (We only know it supports DirectX 10.0, but that’s irrelevant on the Mac. OpenGL 2.1 is likely, given parallel models’ support, but that’s unconfirmed.)
  • How well will the Mac drivers work?
  • How well will they support Core Image?
  • With fire-sale prices on older MacBook Pros, with FireWire 400 onboard and a superior GPU (relative to the MacBook), why are you wasting your time reading this story?

Got all that? On the upside, the 9400M series does represent a theoretical gain over the previous 8400M (though they do have very different architectures), with a higher clock speed and more minty freshness and such. And HD video decoding ought to go pretty nicely. NVIDIA also touts support for its processing-on-the-GPU standard, CUDA, though I wonder what that means for Apple’s (and others’) upcoming support for OpenCL. And there’s PhysX support, which probably doesn’t mean anything to almost anyone.

There’s really a deeper question here, though, one that goes way, way beyond a new Apple laptop announcement. That question is, just how will these hybrid machines perform? AMD/ATI is working on it, NVIDIA is working on it, Intel is working on its own GPU solutions. We’ve got a lot of questions ahead. Stay tuned.

9300M GS at notebookcheck.net

notebookcheck.net benchmark list (note that the 9300M GS lies somewhere just shy of ATI X1400 land, though that’s not a real-world indicator, really, let alone one that tells us about all the potential compatibility pitfalls in live VJ software)

NVIDIA GeForce 9100M G mGPU motherboard GPU architecture, 9300M GS and 9200M GS discrete GPUs

Updated: Here’s what you have to do to switch to low-power, integrated-only graphics. Not too big a pain here, but what if you’re on a plane trying to save battery life and had a bunch of work open, etc.? It’s a pain. They’ll fix this eventually, I’d guess. (Early shipments of AMD/ATI’s competing tech had the same deficiency, before they … fixed it.)