1.42 GHz 7455s (XC7455B1400PF)

Posted:
in Current Mac Hardware edited January 2014
I'm glad somebody finally peeled the heatsink off one of these so we could see the stamp on the chips... www.hardmac.com



So...



XC = pilot production prototype (bleeding edge)

7455 = 7455 part

B = revised process (I wonder what changed)

RX = CBGA package

1400 = 1400 MHz

P = 1.85V core voltage, 0-65C operating temps

F = revision 3.3

Comments

  • Reply 1 of 16
    mrmistermrmister Posts: 1,095member
    Care to do any analysis?
  • Reply 2 of 16
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by mrmister

    Care to do any analysis?



    Not much to analyze, errata fixes, mostly? The "B" is intriguing.



    This does prove the 1.42 GHz Power Macs are using 7455s though...some people needed to be convinced they weren't 7457s. This also disproves once again the claim that Apple is overclocking Moto CPUs beyond their rated clockspeeds.
  • Reply 3 of 16
    overhopeoverhope Posts: 1,123member
    Quote:

    Originally posted by Eugene

    This also disproves once again the claim that Apple is overclocking Moto CPUs beyond their rated clockspeeds.



    Obviously my math isn't very good: I could have sworn that 1.42 GHz isn't quite the same as 1400 MHz...
  • Reply 4 of 16
    fran441fran441 Posts: 3,715member
    One of my younger cousins got the DP 1.42 GHz Power Mac G4 last week and we opened it up to see what it was like. The heat sink on that machine is huge! I couldn't believe it when I first saw it. Thankfully, the machine seems to run nice and quiet so it must be working well.



    I like the blue board too, looks spiffy.
  • Reply 5 of 16
    jlljll Posts: 2,709member
    Quote:

    Originally posted by Overhope

    Obviously my math isn't very good: I could have sworn that 1.42 GHz isn't quite the same as 1400 MHz...



    I don't that Apple would even think about overclocking if the result is a 20 MHz bump



    167 MHz system bus * 8,5 = 1,419.5 MHz.
  • Reply 6 of 16
    amorphamorph Posts: 7,112member
    1.85 volts?! Wow, they might as well mount a turbo on the thing.



    No wonder those chips are cooled by Mount Heatsink.
  • Reply 7 of 16
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by Amorph

    1.85 volts?! Wow, they might as well mount a turbo on the thing.



    No wonder those chips are cooled by Mount Heatsink.




    The 1 GHz and 1.25 GHz MDD macs were 1.85V too. Where have you been?
  • Reply 8 of 16
    matsumatsu Posts: 6,558member
    Aren't there slightly lower voltage versions of those though? At least the 1ghz part, or mebbe not, iDunno.
  • Reply 9 of 16
    amorphamorph Posts: 7,112member
    Quote:

    Originally posted by Eugene

    The 1 GHz and 1.25 GHz MDD macs were 1.85V too. Where have you been?



    Excuse me if I don't check processor voltages religiously.



    That's pretty damn high for a Mot processor, isn't it?
  • Reply 10 of 16
    zapchudzapchud Posts: 844member
    Quote:

    Originally posted by Amorph

    Excuse me if I don't check processor voltages religiously.



    That's pretty damn high for a Mot processor, isn't it?




    That's pretty damn high, yeah! The 7457 is 1,3V, and the low-power version 1V, rated at 12,6W and 7,5W @ 1GHz respectively.
  • Reply 11 of 16
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by r-0X#Zapchud

    That's pretty damn high, yeah! The 7457 is 1,3V, and the low-power version 1V, rated at 12,6W and 7,5W @ 1GHz respectively.



    There are 1.3V, 1.6V and 1.85V 7455s. So far there are 1.1V and 1.3V 7457s listed, but I'd bet there's also a 1.5V+ version out there...
  • Reply 12 of 16
    wmfwmf Posts: 1,164member
    It's not overclocked, but that 7455 is de-rated for temperature; the stock ones are rated for 100C IIRC. Word on the Net is that Apple wanted a faster G4 at any cost, so Moto produced some 7455s that will run fast as long as you keep them cool (hence the massive copper heatsink).
  • Reply 13 of 16
    zapchudzapchud Posts: 844member
    Quote:

    Originally posted by Eugene

    There are 1.3V, 1.6V and 1.85V 7455s. So far there are 1.1V and 1.3V 7457s listed, but I'd bet there's also a 1.5V+ version out there...



    Yep, so do I think too. If Apple are planning to use higher-speed 7457's, they will need higher voltage than 1.3
  • Reply 14 of 16
    eugeneeugene Posts: 8,254member
    Interestingly enough, MacBidouille has pics of an Xserve daughtercard with the markings "XC7455ARX1333SF"



    Most notably these 7455s are rated up to 75C operating temps.
  • Reply 15 of 16
    wmfwmf Posts: 1,164member
    The developer note on the latest dual 1.42GHz Power Macs just came out:



    http://developer.apple.com/techpubs/...cG4/index.html



    U2 supported 1394b all along. They were probably waiting for the PHYs to be released.



    I'm not sure why it uses a PCI USB controller since KeyLargo has USB.
  • Reply 16 of 16
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by wmf

    U2 supported 1394b all along. They were probably waiting for the PHYs to be released.



    Not surprising. The red eBay motherboard that appeared before the original MDD Power Macs were released had the FireWire 800 connector. I just assumed 1394b support was there, just without the appropriate connector fitted to the board.
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