iPhone 3GS uses an ARM Cortex A8 CPU and PowerVR SGX GPU

Discussion in 'iPhone' started by MGLXP, Jun 10, 2009.

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  1. MGLXP macrumors regular

    Joined:
    Sep 29, 2005
    #1
    Apparently, even though Apple hasn't said anything yet, according to AnandTech, the iPhone 3GS uses the same ARM Cortex A8 and PowerVR SGX CPU/GPU combo as that use in the Palm Pre. The article by Anand is an interesting read...everyone should take a look.

    About the CPU:
    "If the ARM11 is like a modern day 486 with a very high clock speed, the Cortex A8 is like a modern day Pentium. The A8 lengthens the integer pipeline to 13 stages, enabling its 600MHz clock speed (what I’m hearing the 3GS runs at). The Cortex A8 also widens the processor; the chip is now a two-issue in-order core, capable of fetching, decoding and executing two RISC instructions in parallel.

    The ARM11 processor in the iPhone/iPhone 3G has a basic vector floating point unit, but the A8 adds a much more advanced SIMD engine called NEON. The A8 also has twice as many double precision FP registers as the ARM11. The addition of NEON and the improved vector FPU in the A8 makes the processor much less like the original Pentium and much more like Intel’s Atom. Granted, Atom is significantly faster than the A8, but it also draws much more power.

    Caches also get a significant improvement. I believe Apple will be using a derivative of Samsung’s S5PC100, which has a 32KB/32KB L1 cache (I/D, we may see a 16KB/16KB config instead) and a 256KB L2 cache. The L2 cache, as you’ll remember from the first section, is a new addition to the A8; the ARM11 core didn’t have an L2."

    About the GPU:
    "In its lowest end configuration with only one USSE pipe running at 200MHz, the SGX can push through 7M triangles per second and render 250M pixels per second. That’s 7x the geometry throughput of the iPhone 3G and 2.5x the fill rate. Even if the SGX ran at half that speed, we’d still be at 3.5x the geometry performance of the iPhone 3G and a 25% increase in fill rate."
     
  2. fireshot91 macrumors 601

    fireshot91

    Joined:
    Jul 31, 2008
    Location:
    Northern VA
    #2
    Good news!

    I'd love to see a higher clock than 600 though for the CPU. I mean, they're pretty much making the iPhone like a super mini computer- I'd like at least a 1Ghz processor, with 256mb RAM. They're good on the RAM part.
     
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