The Impact of Larger Memory

Apple doubled memory capacity on the new iPad to 1GB, marking the first time in recent history that Apple's flagship product offers a similar amount of memory to the current crop of high-end Android devices. Apple's iOS can do a relatively good job with limited system memory as it will conservatively unload applications from memory in the event that it needs to free up more space. iOS does not support paging to flash, making DRAM size a hard limit for developers looking to really push the platform.

Apple has always been conservative on DRAM sizing because it's a great way of reducing the BOM (Bill of Materials) cost. If Apple can make up for having less DRAM by being more aggressive in software (read: kicking apps out of memory), it's a tradeoff that makes sense. It's really Apple's foray into gaming that has added pressure to increase memory sizes.

With the move to the Retina Display, the amount of memory needed to store a single frame increases by 4x—from 3MB to 12MB. Assuming two buffered frames you're looking at 24MB of RAM just to smoothly display what you're seeing on the screen.

The bigger problem isn't the frame buffer, but rather all of the other data you need (e.g. level data, textures, etc...). The higher the screen resolution, the more important it is to have higher quality assets in your game. Texture compression can go a long way, but at some point there's simply more data to deal with as game complexity increases. It's not just about the increase in resolution either. As GPU horsepower increases, so will the complexity of what game developers try to build.

While the frame buffer size increased thanks to the Retina Display, total system memory increased by a much larger amount. With 1GB of memory, game developers are now less constrained.

A more immediate benefit is apps and web pages will remain resident in memory longer as you open open up and switch to other apps. For example, on the iPad 2 if I open four tabs in Safari (AT, Engadget, Reddit, and Tech Report), open iPhoto, run Infinity Blade 2 and GTA 3, switching between the latter two will always require a full game reload (as in you see the intro and everything before you pick up where you left off). On the new iPad, with the same setup, I can switch between Infinity Blade 2 and GTA 3 and automatically resume where I last left off thanks to the extra DRAM. You can still create a scenario where even 1GB isn't enough, it's just that the limit is now higher than it was on the iPad 2.

A Word on Packaging & Looking Forward GPU Performance
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  • Jamezrp - Wednesday, March 28, 2012 - link

    Didn't want to cause Verizon too much trouble? Heh, very funny. I am amazed at how the iPad ends up being an amazingly good Wi-Fi hotspot. It almost seems like business users should opt to get an iPad for that function alone. I know plenty of people who would be happy to keep it in their bag, with the hotspot feature enabled constantly, while travelling about. Even for the price there is nothing even close that can compare.

    Plus, you know, you get the tablet too.
  • supertwister - Wednesday, March 28, 2012 - link

    "It’s a quantum leap from the noisy, 0.7MP mess that was the iPad 2 camera."

    Interesting choice of word considering a quantum is the smallest possible division for a quantity...
  • omion - Wednesday, March 28, 2012 - link

    Quantum leap:
    (n) an abrupt change, sudden increase, or dramatic advance

    The phrase comes from the ability of particles to make a sudden jump between two energy levels. It is a leap (of any amount) between two quantization levels, not a leap of the smallest possible amount.
  • drwho9437 - Wednesday, March 28, 2012 - link

    A large fraction of the die doesn't seem to have a known use? Wondering what could be taking up all that area if not GPU, CPU and memory interfaces/caches... Most other I/O would have small footprints...
  • tipoo - Wednesday, March 28, 2012 - link

    The 4S had a larger than usual die for its voice cancellation features that were needed to make Siri work well, the iPad does't have that but it does have voice dictation so some space is probably for that.
  • PeteH - Wednesday, March 28, 2012 - link

    A big chunk of it is probably the ISP they talked about when the 4S debuted.
  • Lucian Armasu - Wednesday, March 28, 2012 - link

    So this is how I assumed. The new iPad is in fact slower than the iPad 2, if games actually start using the 2048x1536 resolution for their apps, which everyone seems to be encouraging them to do. But once they do that the graphics will either look poorer, or they will be slower than they were on the old resolution, even on an iPad 2.

    Add that to the fact that apps are much bigger in size with the retina resolution, and the CPU is the same as last year. The new display might look great, but it's obvious that the new iPad is absolutely a step-back in terms of performance, whether it's GPU or CPU we're talking about. Hardly worth an upgrade, especially for iPad 2 owners.
  • xype - Thursday, March 29, 2012 - link

    Blah blah blah performance blah not worth it.

    I don’t give a shit about theoretical performance that I might be getting if DNA folding software was available for tablets. I really, really give a shit about being able to read website and ebook text without my eyes straining after an hour.

    One would think that 10 years after "No wireless. Less space than a nomad. Lame." and Apple raking in millions and billions of profit, those Geek Metrics™ that people are so fond of here (nothing wrong with that, it’s interesting stuff!), would be recognized as completely and utterly worthless to the average population. But apparently not.

    The iPad was never ment to replace PCs and Consoles as a hardcore gaming device, and it was never ment as a render farm server replacement. It would be really nice if people realized that, at some point. In the next 5 years, perhaps.
  • tipoo - Thursday, March 29, 2012 - link

    It seems a bit like the 3GS-4 transition, it used the same GPU despite higher resolution and so performed worse at native, although in this case the CPU is unchanged and the GPU is "only" 2x better for 4x the pixels. Developers got around that on the 4 by making games for the old resolution and using upscaling mode. I'd imagine they will do the same here once games hit the limits of the GPU at native. Games like Infinity Blade 2 also use separate resolutions for things like the menus vs shadows vs terrain textures.
  • darkcrayon - Thursday, March 29, 2012 - link

    I guess if the only thing you bought an iPad for were games, and you could only consider a game to be worthwhile if it were drawn directly at 2048x1536, you'd have a point. But of course the new iPad could play games at the "iPad 2" resolution at much higher detail, or at a slightly resolution with the same detail, etc.

    It doesn't make sense to say it's a step backward in performance overall- it simply has the option to display much higher resolution graphics that the old model didn't have. The iPad 2 displays 2048 x 1536 text at "0 mhz" so to speak. It's not like you are losing anything by having the option of ultra high resolution if the type of game (or app) can use it within the hardware capabilities.

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