difference between G3 and G4?

Discussion in 'Macintosh Computers' started by d-fi, Feb 19, 2004.

  1. d-fi macrumors member

    Jan 12, 2004
    Calgary, Canada
    I've been wondering about the differnece between the G3 and the G4. Since i might be getting a 300mhz G3 blue/white tower.

    Since i might be grabbing this soon i've been looking around at the various upgrades that are around. (ram, harddrive, ect) After looking around for a bit i noticed the processor upgrade kits that are around for the blue/whites.

    one kit will upgrade it to a 500mhz G4 and the other will up it to a 900mhz(aprox) G3

    what is the big difference between these processors? According to the one benchmark i saw the 900mhz G3 is faster (then the 500mhz G4) but how is the G4 different?

    any help you can give would be appreciated :)

  2. Dont Hurt Me macrumors 603

    Dont Hurt Me

    Dec 21, 2002
    Yahooville S.C.
    G3 + altivec =G4. how many years now? nothing like a clock cycle go for the 900 G3. those cpu cycles will make up for altivec, G4 500 is about equal to a G3 600 or 700.
  3. Sun Baked macrumors G5

    Sun Baked

    May 19, 2002
    1. Faster MPX frontside bus (modified protocol) to G3's 60x bus

    2. L3 cache capability

    3. MESI cache coherency (needed for dual CPUs)

    4. Better Integer & FP cores

    5. Deeper pipeline (though some would call that bad since a G3s shorter pipe will smoke a G4 at the same clock)

    6. Probably more that I'm not thinking of...
  4. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Ok, there's one very simple answer, and one very technical one, both correct. Here's another answer in the middle:

    There are actually a lot of different processors in the G4 family; the really early ones were basically identical to a G3 with an extra Velocity Engine (Altivec) unit stuck on, while the later ones have a lot more changes to the architecture offering performance gains and differences for reasons past Altivec. The G3s didn't see as many changes.

    But in practical terms all that doesn't matter a whole lot for what you're looking at--an upgrade to an older machine. Basically, the difference depends on what you're doing.

    The G4 will be much faster with certain operations that make good use of Altivec (probably about twice as fast as a G3 at the same clock speed, and can be even more). OSX is also designed to take pretty good advantage of a G4, so you'll get some general boost if you're running OSX.

    That said, the 900MHz G3 has a clock rate so much higer than a 500MHz G4 that unless you're doing something that is very Altivec optimized (maybe certain Photoshop filters, for example), the G3 is going to come out on top most of the time.

    Can't really go wrong either way, though.

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