Effects of Memory on Rosetta Performance

Written by: Adam Christianson

Categories: Reviews

Message from Adam: Listener Stephen sent me this email with some great observations about the effect additional memory has on Rosetta performance in the new Intel systems.

Well, I’ve had my 17-inch iMac Core Duo, for 15 days now. I’ve used in 512 MB, 1 GB, and 1.5 GB memory configurations.

I purchased this machine as pretty much a tower. I always knew I wanted to get an intel Mac as soon as they were released. I had hoped that that would mean I could replace my 12-inch Powerbook 1.5GHZ G4 with something like a 13-inch Mac Book Pro. Of course, Apple did not make a sub-15 pro notebook and may not ever again. Because of this I decided to keep my Powerbook, for I don’t need more power than the 1.5GHZ G4, when not at my desk. Furthermore, at my desk I always have it connected to my Apple Cinema Display, so I have a desktop experience.

However, I still wanted an intel Mac, so I ordered the 17-inch iMac Core Duo. I didn’t get the 20-inch because I wanted to keep my Apple Cinema Display as the main screen, and the new iMac brilliantly supports (finally) DVI output, so my new setup is great.

Well, the first three days or so I had to use the iMac Core Duo with 512MB of memory and it was dreadful. I use quite a few applications at a time with the large amount of screen real estate I have, but even with just Safari, iTunes, Mail, and maybe one or two other small applications the system would really lag with 512 (I was used to 1.25GB on my Powerbook). Furthermore, Rosetta applications were pretty annoying with 512MB. You definitely wanted to have the Rosetta application as the only application running, with 512 MB. Basically, I feel pity for *anyone* who uses the intel machines with 512MB of memory. It doesn’t even begin to work properly unless you use one application at a time (and then have it not be a memory intensive application).

Then I got a 512 stick to add to my iMac. Wow. What a difference. It was finally the fastest Mac I had ever used. 1GB from 512MB was a world of difference. I would say that 1GB is plenty of memory for most users, particularly when using native applications. I can have basically anything intel native I want open, and it handles it with ease (even if I have applications covering both displays). However, when using Rosetta applications you really need to cut back on the amount of applications open. Well, you don’t have to, but if you want the quick performance.

Here is something key I want to point out: When it has enough memory, the iMac Core Duo 1.83 GHZ easily outperforms my 1.5 GHZ Powerbook G4, under Rosetta applications (including Photoshop). Rosetta isn’t that bad at all. If someone is upgrading from a G4, they could certainly get by using Rosetta, for it should still be faster compared to G4, if they have plenty of memory. Toast, EyeTV editing, Photoshop, Word, etc (rosetta applications). are all faster on my iMac Core Duo than my 1.5GHZ G4 Powerbook, if there is memory available for them.

Now I have upgraded to 1.5 GB of memory (returned the 512 stick I got and replaced with 1GB stick). Again, another big step up. Now the Rosetta applications are even more impressive. I must say I’m pretty blown away at how efficient Rosetta is. Yes, you need a *lot* of memory, but if you have these applications really move along. I’ve performed various filters, blurs, etc. side by side in Photoshop, and the intel iMac certainly outperforms my Powerbook G4 1.5 GHZ.

I’m sure 2GB of memory wold help even a little more, under Rosetta applications and allow you to use more of them side by side.

So my recommendation: Any user needs 1GB of memory on these Core Duo machines, they are memory hungry. Furthermore, if someone uses a lot of Rosetta applications and would like to use a couple intensive Rosetta applications simultaneously (along with just about as many intel applications as they want for those aren’t very demanding) then 1.5 GB to 2GB of memory is really what they need, and they’ll be blown away.

I hope people don’t get too put off by the 512 MB stock memory in these systems. It really isn’t sufficient.

There are 19 comments on Effects of Memory on Rosetta Performance:

RSS Feed for these comments
  1. Matt Hoult | Feb 19 2006 - 03:38

    Very interesting; thanks for the break down Stephen.

  2. cctoronto | Feb 19 2006 - 04:22

    Cool. great info… thanks!

  3. rstroud | Feb 19 2006 - 04:20

    Good to know! If/when I get my MacBook, I’ll be sure to order some RAM from Crucial.

  4. debbie T | Feb 19 2006 - 06:51

    Excellent observations, Steve. Thanks for posting it, Adam!

  5. g0rdo | Feb 19 2006 - 09:18




    ram ram, ram, RAM, RAM, RAM!, RAM!!, RAM!!!


  6. isaiah1112 | Feb 20 2006 - 07:18

    Cool, I am glad to hear that with enough RAM Rosetta will actually match up with the 1.5ghz G4! Good news for me to take to my boss!

  7. macFanDave | Feb 20 2006 - 08:15

    I had heard that Rosetta was a “memory hog”, but I am glad that Stephen put that into a tangible perspective with his observations.

    Nowadays, RAM is a relatively cheap commodity, so anyone who was waiting for Univeral Binaries to come out to get a Mactel can go ahead, buy sufficient memory and be happy now.


  8. mTorbin | Feb 20 2006 - 09:38

    I tand my ground in that I think these things are not all that they’re cracked up to be. Thank yo, but I’ll be getting a PowerPC G5 soon, not an Intel.

  9. Bruce | Feb 20 2006 - 12:25

    Very good to know. I’m still conflicted wether to buy the Intel iMac or not, but hearing stories such as this make me inch ever closer to opening up my wallet.


  10. Paul | Feb 20 2006 - 01:21

    Well done Stephen, I am now on my way out to get my 17″ iMac with 2Gig RAM

  11. Jamie | Feb 20 2006 - 02:04

    I too have a 17″ Core Duo, originally configured with 512 RAM. I can confirm that it was horrible when using PS under Rosetta, and could barely cope with iMovie and safari at the same time. Now, I have allso upgraded to 1.5 gigs, and can backup what Stephen was saying about the big performance increase! – PS is MUCH better, very usable, and I can even use two or three rosetta apps at a time along with Safari, Mail, and more!

    I can also run Windows XP using ‘Q’, giving XP 512 RAM, and still adequatly use PS (CS2 btw), safari, mail, itunes with ease.

    GET MORE RAM = moral of story

  12. Tyson | Feb 20 2006 - 03:39

    I was curious to how much ram you have in your PowerBook that you are comparing performance with. My PowerBook is maxed out and I noticed a huge difference in performance from the stock configuration so that seems pretty important when comparing. I’m glad to hear Photoshop is running so well. That was my biggest havoc with getting an Intel Mac before CS3 comes out which is still far ahead.

  13. Zul | Feb 20 2006 - 03:57

    I was also surprised by how fast photoshop was with 1.5GB of ram. It is daster than on my g4 powerbook.

  14. tykal | Feb 20 2006 - 04:15

    This is great to see a somewhat quantitative analysis of the Intel Mac. It would make me want to buy an Intel Mac if they shipped with 1GB of RAM. Given that most proapps won’t be available in Universal until March/April, wouldn’t Apple, in the interest of maintaining sales, ship them with more RAM (considering the large performace difference). This would most certainly temp more people into purchasing the new Macs especially me.

  15. g0rdo | Feb 20 2006 - 07:42

    why does everyone like photoshop? And why would you get a computer that had to filled up to the max with RAM just to use a couple extra apps at the same time… especially a computer that claims to be… (pssshhhhehe) 2X faster……..!!!!

  16. g0rdo | Feb 20 2006 - 07:26

    Right now I am running Mail, Safari, iChat, Address Book, iTunes, Preview, Pages, and Core Image Fun House all at the same time on my eMac (1.25GHz G4, 512 MB RAM) and I have great performance.
    Okay, I’m opening:
    and its still … pretty good!

  17. rstroud | Feb 20 2006 - 07:17

    Gordo…you completely misunderstood what 2X faster meant. It was supposed to be on Intel native applications, not PPC emulated. Of course there was a performance hit, you’re emulating a completely different processor architecture (which is pretty amazing though). More RAM is good, OSX has always been kinda RAM hungry.

  18. Katie | Feb 22 2006 - 11:00

    Thanks for the review, this is exactly the kind of information I was looking for. I use the Adobe Suite daily. Nice to know I at least won’t loose any speed when upgrading my 1 GHz machine even if the Apps aren’t Universal yet.

  19. Jan | Mar 07 2006 - 08:09

    I had exactly the same experience. I nearly cried the first day I got the intel iMac 20″. It was much slower than my Powerbook 1.25 with 1.25GB of RAM. I thought I’d wasted my much needed cash. My extra GB of RAM arrived within a few days though, and I’ve been extremely impressed with the computer since.

    A word of warning though – my version of Virtual PC doesn’t work on the intel – it keeps crashing. I noticed the same with a couple of other apps too.