New iMac uses PC133 RAM?!?!?

suckfuldotcomsuckfuldotcom
Posted:
in Current Mac Hardware edited January 2014
Page from the iMac repair manual (DRAFT edition):







PC 133 in the DIMM, huh?



I wonder if you can put <a href="http://www.crucial.com/store/PartSpecs.asp?imodule=CT64M64S4W75"; target="_blank">this</a> in the SODIMM, and then reset the jumpers to 6.5x133 instead of 8x100? I wonder if the bus can handle 133 MHz?



SdC

Comments

  • Reply 1 of 14
    imacfanimacfan Posts: 444member
    What's far more worrying is that it seems to say that 768 is the largest amount of RAM that you can put in the thing - whereas everything else says 1Gb.



    Also, on the 133Mhz point, its not like Apple hasn't done it before - the iBook that I am typing this on at the moment uses 100Mhz RAM, but only a system Bus or 66Mhz. I think that it is so that the RAM is well within operating limits, and to reduce heat, which must be a big concern in that tiny case.



    Hope this helps,



    Dave
  • Reply 2 of 14
    andersanders Posts: 6,523member
    I wonder how big a difference there is between the 66 Mhz and the 100 Mhz iceBooks. Did they change anything besides the bus speed? If not I guess we´ll soon see a 133 Mhz iMac.



    Another thing: I thought the heat would go from the holes in the base and out of the holes in the top. But how do it pass the mother board? It doesn´t look like there are any holes in it.
  • Reply 3 of 14
    imacfpimacfp Posts: 750member
    [quote]Originally posted by iMacfan:

    <strong>What's far more worrying is that it seems to say that 768 is the largest amount of RAM that you can put in the thing - whereas everything else says 1Gb.

    </strong><hr></blockquote>



    You can put in 1GB but you need a computer tech to do it since users can't reach the other RAM port. Users only have access to the one open RAM slot.
  • Reply 4 of 14
    falconfalcon Posts: 458member
    The only reason it uses PC133 RAM is becuase PC133 ram has now become cheaper to manufacture. PC133 Ram is manufactured in much larger quantaties these days, thus bringing down the price compared to PC100 which had risen in price. Standard economics.
  • Reply 5 of 14
    razzfazzrazzfazz Posts: 728member
    [quote]Originally posted by suckfuldotcom:

    <strong>Page from the iMac repair manual (DRAFT edition):



    (...)



    PC 133 in the DIMM, huh?



    I wonder if you can put <a href="http://www.crucial.com/store/PartSpecs.asp?imodule=CT64M64S4W75"; target="_blank">this</a> in the SODIMM, and then reset the jumpers to 6.5x133 instead of 8x100? I wonder if the bus can handle 133 MHz?

    SdC</strong><hr></blockquote>



    Previous Macs, unlike PCs, didn't have any such jumpers. IIRC, both multiplier and FSB overclocking involved soldering, and the latter would also make your system time go 33% faster.



    The G4 could obviously handle 133MHz FSB, but I'm not sure about the chipset.



    And concerning the mention of "PC133" - since you can't operate both slots at different frequencies, I'd guess this is either a mere typo, or because basically every 168-pin DIMMs you can buy nowadays is PC133-compliant (which makes it PC100-compliant too), but most SO-DIMMs are still PC100 only.



    Bye,

    RazzFazz
  • Reply 6 of 14
    apple.otakuapple.otaku Posts: 590member
    Does anyone find it odd that it takes one desktop module and one laptop module. Oh, and could you email me that document? I love reading about this stuff.
  • Reply 7 of 14
    suckfuldotcomsuckfuldotcom Posts: 550member
    I got it from this macnn thread:



    <a href="http://forums.macnn.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=5&t=005360"; target="_blank">http://forums.macnn.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=5&t=005360</a>;



    SdC
  • Reply 8 of 14
    eugeneeugene Posts: 8,254member
    It probably involves moving a resistor or two to get 133 MHz bus speeds. My Beige G3 (now with a G4) bus runs at 75 MHz instead of 66 MHz...but only because there are jumpers on the Beige and B&W Macs.
  • Reply 9 of 14
    thegeldingthegelding Posts: 3,230member
    i thought you could add 512 in so-dimm...am i wrong?? i but to order the 512 so-dimm soon so it is here when my iMac arrives....should i wait?? order 256?? or get the 512??? would really prefer 768 to 512 total in my new iMac
  • Reply 10 of 14
    thegeldingthegelding Posts: 3,230member
    think i have answered my own question:



    <a href="http://www.ramjet.com/ItemDescr.asp?Item=IM512A"; target="_blank">http://www.ramjet.com/ItemDescr.asp?Item=IM512A</a>;



    looks like a good price...g



    but: this is Pc-100

    Crucial is selling PC-133 for the G4 iMac:



    <a href="http://www.crucial.com/store/listparts.asp?Mfr+Productline=Apple+iMAC&amp;model =iMAC+%28G4-800%29&x=9&y=15" target="_blank">http://www.crucial.com/store/listparts.asp?Mfr+Productline=Apple+iMAC&amp;model =iMAC+%28G4-800%29&x=9&y=15</a>



    but for more $....should one go with PC100 or PC133...or does it matter since the system bus is only 100??? help...want to order ram soon...not sure if prices going up or down..g



    [ 01-12-2002: Message edited by: thegelding ]</p>
  • Reply 11 of 14
    thegeldingthegelding Posts: 3,230member
    dang ...ramjet price is for APPLE slot, not user slot...they don't seem to sell the so-dimm for the new iMac in the 512 size yet...guess i will wait for more answers as to whether the USER Slot will hold 512 or only 256....off to search apple site...g
  • Reply 12 of 14
    barry sharpbarry sharp Posts: 11member
    [quote]Originally posted by thegelding:

    <strong>dang ...ramjet price is for APPLE slot, not user slot...they don't seem to sell the so-dimm for the new iMac in the 512 size yet...guess i will wait for more answers as to whether the USER Slot will hold 512 or only 256....off to search apple site...g</strong><hr></blockquote>



    The internal slot for the new iMac Flat Panel holds a PC133 168-pin DIMM up to 512MB. The User Accessible memory slot holds a PC100 144-pin SO-DIMM up to 512MB.



    The 168-pin is same as used in the iMac DV slot loaders. The SO-DIMM is same as the ones used for the iBook Dual USB expansion slot.



    Current prices for these are as follows (ramseeker low prices)



    144-pin SO-DIMM 512($195), 256($65), 128($30) and 64($20)



    The above 144-pin modules can be viewed/bought at <a href="http://www.boundlesstech.com/ibook.html"; target="_blank">http://www.boundlesstech.com/ibook.html</a>;



    168-pin DIMM 512($100), 256($47), 128($23) and 64($9)



    The above 168-pin modules can be viewed.bought at <a href="http://www.ramseeker.com/newimac.shtml"; target="_blank">http://www.ramseeker.com/newimac.shtml</a>;



    Prices may vary by the time you get to the above URLs.



    Regards.... Barry Sharp
  • Reply 13 of 14
    apple.otakuapple.otaku Posts: 590member
    Okay, what other Macs share this same memory? Does the tech slot in the new iMac take the same memory as the Power Mac desktops? Does the user slot take the same memory as the Ti PowerBook laptops?
  • Reply 14 of 14
    eugeneeugene Posts: 8,254member
    apple.otaku...as long as you get low-profile 168-pin PC133 SDRAM DIMMs for the non-user installable slot and low-profile 144-pin PC133 SDRAM SO-DIMMs for the user installable slot, you should be fine.



    Why PC133? It's not much mor expensive if at all vs PC100.



    Why low-profile? Because I can't find any TIL docs that specify any height requirements.
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