IMac 20" GPU vs. IMac 17" GPU vs Macbook Pro GPU

in Current Mac Hardware edited January 2014
I've read a bunch of posts about the underclocking of the GPUs for the MBP. My question is what X1600 series card is in the IMac. Is it different in the 20" vs the 17". Is the Moblity X1600 chip in all three models. I''ve read different rumors about the IMac. One stated that early IMac had the X1600 Pro chip because the Mobility X1600 was not available yet. Another stated that the 20" has the X1600 Pro or XT because of driving the 20 inch screen. Another yet stated that the 20" inch IMac with 128mb GPU is the Mobility X1600 and the 20" inch with the 256mb is the X1600 Pro or XT. Isn't there any utilities software to check your chip and what speed its clocked at? I'm confused .


  • Reply 1 of 3
    Anybody know this?
  • Reply 2 of 3
    eckingecking Posts: 1,588member
    I think I heard the imac is clocked down slightly too. There's this ati app that can clock it back up if need be but I don't remember where you can find it.
  • Reply 3 of 3
    dfilerdfiler Posts: 3,420member
    I've had a couple good chuckles regarding the GPU clock speed of IntelMacs.

    Seems like there has been a rather large, and perhaps justified, reaction to apple not publicizing the GPU clock speed. Some people have mistakenly assumed that the GPU would run at the max frequency quoted by it's OEM. Granted, apple should, and probably will, more precisely explain which x1600 "series" GPU is used in which machines.

    But back to what makes me chuckle... the use of the term "underclocking" to describe apple's GPU frequency. There hasn't been any "underclocking". There has only been "clocking".

    Real world analogy: Car manufacturers frequently buy engines from other manufacturers. These engines are OEM rated up to a certain RPM. However, when put into actual production machines, the engines are run at different RPM and given different redline numbers. Given size, heat, and performance tradeoffs, different manufactures opt for different RPMs.

    Outsourced components are frequently used in different ways by different manufacturers. You'd have to be pretty new to the game or naive to think that all the hardware in a computer is running at max OEM spec and exactly within OEM scenarios of use.

    What am I getting at here? "Underclock" implies that there is some "correct" speed and that everything else is underclocking. This simply isn't the case. Chips have max speeds dependant on voltages and cooling strategies. OEM suppliers quote general numbers given a specific scenario.

    Industrious but naive consumers have kind of shot themselves in the foot by using OEM specs without understanding how the OEM system works. It isn't logical to assume that the x1600 "series" chip embedded in apple products is running at some hypothetical supplier's spec. Manufacturing simply doesn't work that way.

Sign In or Register to comment.