Powermac G5 Dual 2GHZ Memory

Discussion in 'Macintosh Computers' started by thejakill, Sep 16, 2005.

  1. thejakill macrumors 6502


    Sep 8, 2005
    i got a powermac g5 dual 2ghz this spring and it has 1 gb of RAM. would it be worth the money to upgrade to 2 gb of RAM or higher? mostly for iMovie and iDVD.
  2. mad jew Moderator emeritus

    mad jew

    Apr 3, 2004
    Adelaide, Australia
    Almost definitely. Are you seeing a lot of bouncing beach-balls while you work with iMovie/iDVD? It'll certainly limit them. I'd recommend more RAM.
  3. Cooknn macrumors 68020


    Aug 23, 2003
    Fort Myers, FL
    I have the same box and just went from 1GB to 2GB of RAM. Well worth it.
  4. ouphe macrumors regular

    Jun 12, 2005
    Los Angeles, CA
    I've only got 1.5 GB of RAM in my Dual 2 Ghz PM, and it flies compared to almost everything else I've ever worked on. I'm sure you'll be happy with 2 GB!

  5. dmw007 macrumors G4


    May 26, 2005
    Working for MI-6
    I just went and upgraded the RAM in my Power Mac G5 from 1GB to 2GB and have been pleased with the results. The performance is not tremendously different, but it is better.

    So yes, go ahead and upgrade your RAM.
  6. thejakill thread starter macrumors 6502


    Sep 8, 2005
    OK, so if 2 gb RAM makes a difference, would adding even more RAM than that make it even faster, or would it just be overkill?

    keep in mind that i'm only really concerned about RAM for iMovie and iDVD...
  7. dmw007 macrumors G4


    May 26, 2005
    Working for MI-6
    Well, you could always use more RAM. But for your needs I would think that 2GB would be fine. But if you have the extra $$$ then go for 3GB.

    Either way, you are going to be pleased with the results. :)
  8. joecool85 macrumors 65816


    Mar 9, 2005
    Check your page outs in activity monitor. I have a dual 2ghz G5 PM with 1gb ram and I've had it for about a month, I've used iMovie, iDVD, Safari, FirstClass, iChat (most of them at the same time) along with numerous widgets, and I still have 0 pageouts! Meaning, I'm not worried about my ram yet. I'm sure when I start photoshopping (I haven't bought PS for it yet) then I might need more ram. And when I start doing larger projects on iDVD/iMovie then I will need the ram. But, so far so good.

    Bottom line: If you have money, do it. If you kinda do/kinda don't, I wouldn't bother. Like I said before though, check you pageouts.
  9. FFTT macrumors 68030


    Apr 17, 2004
    A Stoned Throw From Ground Zero
    Mixing and Matching Apple and 3rd party G5 RAM

    I'm sure glad you guys brought this up.

    I'm trying to figure out exactly which RAM to buy
    to add another 2 GB to my G5 2.0. ( 8 DIMM Rev B )

    I currently have 4 X Apple 256 DIMMS, but when looking through all the 2 GB kits, I get lost in
    which specification I need so as not to conflict
    with my installed Apple RAM specs.

    Mostly it boils down to the CAS latency ratings, but I can't find those specs for the Apple RAM.

    I think it might be CAS 3, but then what happens
    if you add a pair of high performance CAS 1.5 or 2.0 Single 512 or 1 GB DIMMS, leaving the Apple RAM in place.?

    Or should I stick with normal efficiency CAS 3
    DDR 400 PC 3200 DIMMS ?
  10. dmw007 macrumors G4


    May 26, 2005
    Working for MI-6
    Yes, it is CAS 3 latency that you need for your Power Mac G5 RAM. I am not sure if a lower CAS (i.e.- 2.0 or 1.5) latency RAM would work.

    For that reason, I would just go for RAM that is certified to work with your Mac- better to be safe than to be sorry. Crucial RAM would be highly recommended.
  11. FFTT macrumors 68030


    Apr 17, 2004
    A Stoned Throw From Ground Zero
    I purchased a GeIL 1 GB 2X512 kit from newegg and now may have to return it.

    It might work, but I can't risk a kernel panic.

    I found this a xlr8yourmac.

    Notes on Compatible PowerMac G5 Memory Modules (CAS/CL Timing Requirements)
    I've used two 512MB PC3200 CL3 dimms fine in a Dual G5, but after having several G5 owners report problems with some faster than CL3/CAS3 dimms in their G5s - I've been meaning to post a note here about what I think is the problem. The first report I had on this was about a week ago from a Dual G5 owner (Martin) that said his Geil Golden Dragon and Mushkin Level II black memory (both rated faster than CL3) were not recognized in his G5. My first guess was that the PowerMac G5 required the SPD chip on the DIMM to have CL3/CAS3 timing even if the dimm was rated for lower CAS (faster) timings - despite the Apple Dev. Doc notes. (This was a problem with some CL2 dimms back in 2001 after the G4 firmware update noted in reports/tips page here back then - CL3 timings had to be in the SPD even if the dimm was rated for CL2 timing.)
    Since the Apple PowerMac G4 developer doc notes that it supports other CAS latencies (under Expansion/RAM Expansion section under Figure 4-1 it says):
    "For all microprocessor speeds and for both DDR400 (PC3200) and DDR333 (PC2700) SDRAM DIMMs, the Power Mac G5 supports CAS latencies of 2, 2.5, 3, 4, and 5. "
    I asked Martin to test with only a pair of the (faster rated) DIMMs installed and he said it would not boot. (Since I suspect all dimms will be run at the timing of the slowest CAS/CL timing dimm installed, I wanted him to test with the OEM CAS3 dimms removed to see if it would run with just the faster rated DIMMs installed.) Therefore I concluded that despite the note on support of lower CAS timings than 3, as with the previous firmware updated G4s, the G5 must require the DIMM to have CAS3 timings in the SPD chip, even if the DIMM is rated for lower CL/CAS timings.
    I wasn't sure Martin believed my theory was correct due to the Apple Dev. Docs note (he wrote today that he does), but this weekend I found a thread in the Apple G5 forums that mentioned this was confirmed by a Mushkin tech support person and that Mushkin's product page for their memory lists PowerMac G5 specific modules with a note that says:
    "Designed and Programmed for Apple Mac G5 computers".
    (A reader in the Apple forums thread said he was also told by Mushkin the DIMMs had to have CL3 timing in the SPD to work in the G5.)

    I'm accumulating a list of DIMMs that worked and didn't work and will post that later in a section on the PowerMac G5 Tech Docs/Compatibility/Updates page, but if you're buying memory for a G5, and it's not already listed as compatible, I'd ask the vendor if it is guaranteed to work in your PowerMac G5 model. Ironically the higher-priced (Lower CL/CAS timing) DIMMs are less likely to work than the cheaper/more common CL3/CAS3 DIMMs, but I'd still ask before buying to avoid any surprises and hassles with a return and potential restocking fees from dealers that don't guarantee/test their memory in a G5.

    The question in my mind (and many others I'm sure) is can the PowerMac G5 really run at faster than CL3 timing? (assuming all install dimms have faster rated memory than CL3.) Of course the Dev Docs indicate that, so is the CL3 timing requirement in the SPD just a check at boot to make sure the system can read the DIMM's CL3 timing for cases where there's a mix of memory speeds and CL3 therefore will be the timing used. (i.e. Pairs of CL3 OEM dimms and faster pairs installed at the same time.)
    If all CL2 dimms were installed for instance (and also had CL3 timing in the SPD, required to even be recognized at boot apparently) - will CL2 timing actually be used? (And is there any software that's accurate to even report this -other than trying to run a consistent memory bandwidth test perhaps. If the Benchmark/test had much run/run variation, that could make it less useful for a test like this since the difference in overall performance may be small.)

    And the follow-up

    Note on Early G5 Shipments and Problems with OEM + 3rd Party RAM Mixing
    In a follow-up to the previous posting on 3rd party RAM issues (i.e. if no CL3 timing in the SPD) mentioned in Monday's news, a reader sent a note:
    "Apple has sent a tech note to european resellers telling them about the RAM in the first units delivered in Europe, as described below. It seems it functions as is, but that when 3rd party RAM is added KPs (kernel panics) ensue.
    I got it from a french web site (Macbidouille) who got it from a german web site( Macnews.de). Just thought you should know, since you have reported such problems (with CAS latencies) that might be related. Maybe we can have dual G5s running CAS 2 RAM !
    (Update - macbidouille later reported the issue was only with OEM Hynix modules and that removing them was the recommended solution.)

    Affected units
    1.8GHz product serial number below CK339yyyPAZ, CK339yyyQ66, CK339yyyQ6Z, CK339yyyPB2, or CK339yyyQ68
    1.8GHz CTO configuration product serial number below CK339yyyNVA
    2.0GHz product serial number below CK339yyyPB0
    2.0GHz CTO configuration product serial number below CK339yyyNVB
    Units with serial number greater than CK339xxxxxx are not affected.
    Units with serial number starting with YMxxxxxxxx are not affected.

    The Dual G5 (USA shipment on 9/15) here has a S/N of "XB337...", so I wonder if this one is affected (i.e. is the letter prefix or just the first 3 numbers a key factor - the numbers I'd assume.) However it's working fine so far with two 3rd-party CL3 512MB PC3200 Dimms (no kernel panics to date but I don't get to use it as often as I like.) Apple has a kbase doc on locating the G5 S/N for those that want to check - remove the cover and it's on the lower area where the door mates to the case - Apple system profiler will also report it.
    I wonder is this really an issue with the RAM shipped in them or the system/firmware of the early units? The boot rom version in this Dual G5 (s/n XB337...) per Apple System Profiler is: 5.0.2f2, which I have run with two CL3 512MB dimms + the OEM CL3 256MB dimms without any KP's (so far). (If anyone has later or different G5 boot rom version let me know - see the later news item above for initial reports - 5.0.7f0 is the latest reported to date.)
    On a related note - a recent email from a G5 buyer said his Apple order listing shows "DDR440" memory instead of the usual "DDR400" listing. (Not that the memory bus is going to run at the higher speed.)

    I have written to GeIL support about their Apple compatibility information.

    It seems they may have to re-evaluate what they carry and post new specs
    on their Apple Series DIMMs.

    Thier Apple series RAM was compatible with the original 1.6 and 1.8 single processor G5's
  12. ammon macrumors regular

    Sep 24, 2005
    That is a lot of good info!

    I too was looking to up my 1gb to 2gb. Maybe some day I will be able to afford it...
  13. aviram macrumors newbie

    Oct 6, 2005
    $20 Rebate on PNY 2x512MB kit for G5 ($69.44 after rebate)


    $20 rebate on PNY 2x512MB kit for G5 (Part# D1GBPC32-G5KIT) till Oct 14:


    $69.44 after rebate (I am buying two for a total of 4x512MB)

    I did a lot of research, and for the G5, it seems that the consensus is that it cannot use a "faster" i.e. CL2 memory, and the recommendation is to buy memory strictly by price so long as the manufacturer guarantees compatibility with the G5. Not all PC3200 might be compatible with the G5, strict adherence to JEDEC is required, and the SPD has to have CL3 in it.


    good article, a bit old (esp price wise) here is a short quote from it:

    though there is one conflicting report from http://www.barefeats.com/quick.html

  14. CanadaRAM macrumors G5


    Oct 11, 2004
    On the Left Coast - Victoria BC Canada
    The 8% difference in the Barefeats test is well within the range of measurement error. You can run XBench successive times and have a +/- 10% result on the same machine.

    One thing: how the data is populated on the hard disk can make a difference. Hard disks are much faster at reading from the outside tracks, where the angular velocity is high, vs, the inner tracks. If they cloned the data from one to another, assuming some fragmentation of the original drive and distribution of the data across the inner and outer tracks, then the fact that the second drive was written with files contiguous (de-fragmented) and in order on the fastest tracks of the drive, may account for some (or all) of the difference.

    So far, there is no indication at all that the Mac motherboards can exploit any faster RAM Latency timings. (PS. there are no CL 1.5 modules)

    Personally I would never buy Mac RAM from a discounter like NewBestTigerEggFryBuy.com They do not guarantee compatibility with anything. I would stick to a reputable seller who tests and guarantees compatibility with your model Mac. The SPD settings are all-important, and you CANNOT tell this yourself from any printed specs or by observation.

  15. cabasner macrumors member

    Oct 9, 2005
    Hello all,

    I am not YET a Macintosh owner, instead, I'm trying to learn a bit before taking the plunge. I was going to post a new thread asking about memory upgrades, but then I found this one, but I must admit, not being a knowledgeable computer hardware person, the details in here have me confused.

    I am pondering the purchase of a G5 2.7 Ghz machine. My sister-in-law has said that purchase of aftermarket memory is very much cheaper, and after looking at various prices on the internet, it appears as if this MAY be true. However, there appear to be so many combinations of possible memory that I am thinking that it might just be better to purchase the memory I want with a new machine. I'm interested in either a 4GB or 8GB memory. Apple is asking ~$2000 for the 8GB. The discussion in this thread scares me, as I don't have a clue what would be compatable, and not sure how you buy memory, in 1GB increments, 2GB, etc.

    Thoughts for a real stupid potentail new Mac guy?
  16. jfay@hotmail.co macrumors newbie

    Oct 12, 2005
    Hyper-x ram

    I just thought I'd chime in. I bought 2x512 Kingston Hyper-x ram and it booted up perfectly the first time and everytime since I got it. I even tried buying some Geil Apple specific ram and it didn't show up on my system after installing. I don't know if it was bad Ram or what. I have 4x256 Apple OEM ram, and then the Hyper X on the outside. My computer is only about a month old, so maybe they updated the Bios or something. It's a dual 2.3GHZ powermac. I have like one day left to return this ram and after reading this page, am wondering if I should do so to get some CAS 3 Ram.

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