DDR3-1066MHz vs. DDR3-1333MHz RAM?

Posted:
in Current Mac Hardware edited January 2014
I've had my 21.5" for 2 1/2 weeks and now I want to upgrade. It's the higher-end one with the ATI 4650 HD card and the 1TB drive. Do I have a shot? I just passed the 14-day return window. I definitely want to upgrade to either the new 21.5" higher-end one or, for an extra $200, go with the lower-end 27"...



By the way, FYI, I have 16GB of DDR3-1066 RAM. Some of you may have added RAM as well so I checked that out as well: ALL four models with ALL of its base and upgradable processors support BOTH 1066MHz and 1333MHz DDR3 RAM.



How much of a difference between the two speeds will be noticeable? I could just sell all four of my 4GB DDR3-1066 chips (all NEW! Grrr...) and then buy DDR3-1333's...What a pain...



Any recommendations?

Comments

  • Reply 1 of 12
    dfilerdfiler Posts: 3,420member
    I recommend not worrying about it.



    Seriously though. How can anyone make a recommendation without knowing what you are using the computer for? Because you didn't describe a task that desperately needs a quicker computer, my guess is that you don't actually need a quicker computer.



    I must be getting old. But I honestly wish I had bought an i5 iMac instead of an i7. The i7 runs hot, causing the fans spin up and make a lot of noise. My days of spec-whoring must be over.
  • Reply 2 of 12
    crunchcrunch Posts: 180member
    Thanks, dfiler! So I won't then! I'll have to rip out the 2x2GB DDR3-1333 RAM chips and put my 4x4GB DDR-1066. I hope it really IS compatible lol...Just called my Apple store and they have the 27" in stock and are willing to swap it out (+$200 of course).



    Do I want the Core i5 for an extra $180? (educational discount)? It says on Apple's website that the Core i3 that's in the lower-end 27" model does support Turbo Boost, but according to Intel's website, that's not the case. Arghhhh! They also have an error on there on the ATI card (512MB version)...According to ATI(AMD's site), they're both GDDR5...WTF!????
  • Reply 3 of 12
    futurepastnowfuturepastnow Posts: 1,772member
    The performance difference between 1066 and 1333 memory would be a few percentage points on memory-intensive benchmarks. Measurable, but not noticeable. Don't worry about it.
  • Reply 4 of 12
    Just like Crunch I recently ordered a 27" i7 that arrived today (7/27)! I spoke to apple an they told me to not open the box and they are doing a full exchange for a 2.93Mhz i7 version. In fact, I added a new track pad and a battery charger and after all is said and done, I will get back about $8 on my credit card.



    The one question I have is that the i7 I purchased is configured with 2x2GB of 1333MHz memory (4GB total). I already purchased 2x4GB 1066MHz of memory that was supposed to go into the original system (for a total of 12GB). Does anyone know if the OS is smart enough to be able to mix the 4GB of 1333 and 8GB of 1066, or am I going back ebay?
  • Reply 5 of 12
    crunchcrunch Posts: 180member
    Quote:
    Originally Posted by netispguy View Post


    Just like Crunch I recently ordered a 27" i7 that arrived today (7/27)! I spoke to apple an they told me to not open the box and they are doing a full exchange for a 2.93Mhz i7 version. In fact, I added a new track pad and a battery charger and after all is said and done, I will get back about $8 on my credit card.



    The one question I have is that the i7 I purchased is configured with 2x2GB of 1333MHz memory (4GB total). I already purchased 2x4GB 1066MHz of memory that was supposed to go into the original system (for a total of 12GB). Does anyone know if the OS is smart enough to be able to mix the 4GB of 1333 and 8GB of 1066, or am I going back ebay?



    Congrats on your new iMac...twice over!



    Well, I don't think it depends on OS X as to whether or not the different type of RAM will work. I think it depends solely on the CPU. Please, anyone, correct me if I'm wrong. (@dfiler: You seem very knowledgable about this. Thanks for the advice!)



    At any rate, I'm in the same boat as you. I took out the 4GB (2x2GB) DDR3-1333 chips, and replaced them with, gasp, 16GB (4x4GB) DDR3-1066 modules. Before I swapped the memory out, I decided to play around with it using the 4GB DDR3-1333's, and when I picked up my jaw off the floor after the incredible display had me mesmerized for a good 15 minutes (that's after 2 1/2 weeks on the 21.5" iMac! Yes, it's that amazing!), I pulled the chips that came with it and put in all four of my DDR3-1066 ones. After turning it back on, it booted the system back up with no problems and I've been configuring everything for the last several hours.



    The service at the Apple store was excellent as usual. The manager quickly waived any and all restocking fees and simply let me swap out my 2 1/2 week-old 21.5" model for a brand spanking new 27" one. He even hooked me up with a $100 discount. I'm loving this thing!
  • Reply 6 of 12
    Any computer will let you mix different speed memory (as long as it's all the right type), it will just run it all at the slower speed.
  • Reply 7 of 12
    crunchcrunch Posts: 180member
    Quote:
    Originally Posted by FuturePastNow View Post


    Any computer will let you mix different speed memory (as long as it's all the right type), it will just run it all at the slower speed.



    Really?...I would have guessed otherwise. That will come in very handy for me.



    That said, are you absolutely sure that there is no downside whatsoever to mixing DDR3-1066MHz with DDR3-1333MHz RAM modules, to use the new iMac's as an example, as long as it is the correct kind of course?
  • Reply 8 of 12
    dfilerdfiler Posts: 3,420member
    Quote:
    Originally Posted by Crunch View Post


    Really?...I would have guessed otherwise. That will come in very handy for me.



    That said, are you absolutely sure that there is no downside whatsoever to mixing DDR3-1066MHz with DDR3-1333MHz RAM modules, to use the new iMac's as an example, as long as it is the correct kind of course?



    Motherboards have long had the ability to clock various parts of the system at different rates. Tweekers are notorious for bumping up those speeds until instability is encountered, and then backing off a tiny bit.



    Under normal circumstances, the ram is interrogated in order to find out its capabilities. The speed of the slowest stick is what governs the overall clock rate.
  • Reply 9 of 12
    Thanks for all the info...



    I just found out something interesting from the place I get memory from. I had a discussion with the tech guy over there and he told me... "Don't buy the 1333MHz memory for the new iMac yet. The 1333MHz memory that is being produced is a very high CAS latency of 8 or 9, while a lot of the 1066MHz is at CAS latency of 7. The higher latency will actually defeat a lot of the performance benefit with the latest Mac motherboards. In addition, you can over-clock the 1066MHz memory, but cannot with the 1333MHz" . According to him, If I mix the 1066MHz and 1333MHz, the system will align itself to the 1066MHz, but I will inherit the slower CAS latency of the 1333Mhz.



    I found this conversation to be pretty interesting and the guy seemed to know a lot about memory. As was suggested earlier in this thread, this guy mentioned that the 1333MHz memory would only show better performance with the some specific applications and benchmark testing. but the vast majority of people will never see a difference. He said "Only people like serious gamers *might* notice a difference and they will probably want to stick with the 1066MHz once they are able to over-clock".
  • Reply 10 of 12
    crunchcrunch Posts: 180member
    Quote:
    Originally Posted by netispguy View Post


    Thanks for all the info...



    I just found out something interesting from the place I get memory from. I had a discussion with the tech guy over there and he told me... "Don't buy the 1333MHz memory for the new iMac yet. The 1333MHz memory that is being produced is a very high CAS latency of 8 or 9, while a lot of the 1066MHz is at CAS latency of 7. The higher latency will actually defeat a lot of the performance benefit with the latest Mac motherboards. In addition, you can over-clock the 1066MHz memory, but cannot with the 1333MHz" . According to him, If I mix the 1066MHz and 1333MHz, the system will align itself to the 1066MHz, but I will inherit the slower CAS latency of the 1333Mhz.



    I found this conversation to be pretty interesting and the guy seemed to know a lot about memory. As was suggested earlier in this thread, this guy mentioned that the 1333MHz memory would only show better performance with the some specific applications and benchmark testing. but the vast majority of people will never see a difference. He said "Only people like serious gamers *might* notice a difference and they will probably want to stick with the 1066MHz once they are able to over-clock".



    Wow, very interesting indeed! Can anyone confirm this? If you switch between computers like I have been, DDR3-1066 is compatible with almost everything manufactured in the past several years, whereas DDR3-1333 is fairly new. It is certainly brand new to the Mac! I only have DDR3-1066 SODIMM's, but plenty of 'em.
  • Reply 11 of 12
    Quote:
    Originally Posted by Crunch View Post


    That said, are you absolutely sure that there is no downside whatsoever to mixing DDR3-1066MHz with DDR3-1333MHz RAM modules, to use the new iMac's as an example, as long as it is the correct kind of course?



    Unless Apple deviates significantly from hardware standards, it should work fine.
  • Reply 12 of 12
    guinnessguinness Posts: 473member
    You'll never notice a difference between 1066 and 1333 MHz in real world apps. I have 1600 MHz DDR3 in my PC, and have to overclock the CPU just to get it running near that speed, otherwise the RAM runs at 1333 MHz. But I don't notice a difference between 2.6 GHz and 3.0 GHz on my Core i5, other than in benchmarks.
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