Linked by Thom Holwerda on Mon 23rd Jan 2006 17:59 UTC, submitted by Sean Long
Apple "I decided to do some simple tests to see how important RAM is when running applications under Rosetta. If you rely heavily on applications that are not yet universal make sure you load that new Intel Mac up with 1.5 - 3.77 times the RAM in your current PowerPC machine."
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Is this really a huge surprise?
by steveftoth on Mon 23rd Jan 2006 18:25 UTC
steveftoth
Member since:
2005-10-30

The applications are recompiled dynamically to x86 code. So they have to have all the old PPC code, as well as the new x86 code in memory to function. And depending on how the program laid out its memory, it may require more memory to emulate that when compiled to x86 code.

Reply Score: 4

64 Bit
by mlb2000 on Mon 23rd Jan 2006 20:40 in reply to "Is this really a huge surprise?"
mlb2000 Member since:
2005-09-07

Is that PPC (now legacy?) code using 64bit space as well? Could that account for the extra? i.e. 64bit + 32bit + chunking = extra RAM requirements.

Reply Parent Score: 1

RE: 64 Bit
by nimble on Tue 24th Jan 2006 05:52 in reply to "64 Bit"
nimble Member since:
2005-07-06

Is that PPC code using 64bit space as well?

No, Rosetta emulates a G4, which doesn't support PPC64.

(now legacy?)

Not yet. Apple still sells PPC, and at least the G5 boxes are still pretty competitive.

Reply Parent Score: 1

Get a Life Member since:
2006-01-01

Who said it was surprising that running a program in Rosetta will use more memory? It certainly wasn't that little blog entry, and as luck would have it you're the first person to comment on this article so it can't be anyone here.

Since you don't require testing to know how much more memory will be used to achieve a reasonable performance profile for these applications, why don't you tell the rest of us that might otherwise be forced to attempt to determine such information empirically. It would save everyone a lot of time and the world lots of reporting of awkwardly-obtained datapoints.

That is, unless you don't actually know how much more memory is used.

It's also interesting to note that it isn't strictly necessary to keep all of the code in memory. That sort of takes a secondary role to people complaining about the very act of presenting information on a subject they feel is "obvious." There's already more than one knee-jerk response here, alone. It's absolutely bizarre that it's this, and not his methodology that is criticized.

Reply Parent Score: 0