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TheSpaz · Jan 30, 2007, 10:23 AM

I have a Mac Pro at home and a G5 at work. The Mac Pro has 3GB of RAM and the G5 has only 1GB of RAM. I use MenuMeters both at work and at home. When I boot the G5 and start working, it shows 260MB of RAM already being used by the System, Suitcase, Safari and Illustrator CS 2. However, at home when I boot up my computer, it shows 500MB already in use without opening any Apps at all!... what the?

I don't have anything usual running in the background at home or at work.
I run more dashboard widgets on the G5. I run 1 widget on the Mac Pro (Swap Usage Widget)

Once I get a few things running on the Mac Pro like Safari, iChat, EyeTV and stuff, my RAM usage goes easily up into the 1GB area.

The other thing would be is... does it know it can use more RAM when more RAM is there to use? Like, does it see that I have 3GB and gives Applications an extra amount so they run smoother or something?

TheSpaz · Jan 30, 2007, 10:23 AM

Both computers are running Mac OS X 10.4.8. I also forgot about Rosetta but, how do you even see if Rosetta is running or not. Which process is it? I find it amazing that I can be running Photoshop, Illustrator, Safari, Mail, Quark, Suitcase and the rest of the OS using less than 400MB of RAM, while the Mac Pro uses 500MB running nothing but the Finder.

I forgot to mention, I checked Activity Monitor on my Mac Pro and all of the processes are "Intel". kernel_task uses up the most RAM but, I think that's normal. Does anyone else have both an Intel Mac and a PowerPC Mac to compare RAM usage on? Why is the Intel Mac RAM usage doubled? That's a big difference. I get by on 1GB of RAM at work easily. I hardly ever have page outs but, on 1GB of RAM on the Mac Pro, it's definitely not enough RAM. It's hard do anything without getting page outs. I also use a lot more Apps at work than at home too! I use a lot of design Apps at work while at home I only use iChat, Safari, EyeTV, Mail, iPhoto and sometimes Logic Express, iMovie and Toast 7. I'm planning on using Logic Express more as soon as my band is ready to do some heavy recording.

Gavin · Jan 30, 2007, 11:42 AM

The answer is yes. It knows you have more ram so it makes use of it. Caches more things, like folder listings and maybe even the volume control, etc.

It could also be CPU sensitive. Maybe the intel chip can handle more threads so it allocates more off the bat.

TheSpaz · Jan 30, 2007, 01:02 PM

That makes a lot of sense. Thanks for that info.

Chuckit · Jan 30, 2007, 01:56 PM

Originally Posted by TheSpaz

Both computers are running Mac OS X 10.4.8. I also forgot about Rosetta but, how do you even see if Rosetta is running or not. Which process is it?

In Activity Monitor, apps with the kind "PowerPC" are running in Rosetta.

mduell · Jan 30, 2007, 07:03 PM

Apple apps are going to use more memory. On PowerPC they set the compiler to optimize for size, but with Intel they've switched to optimize for performance.

Older, unupdated (PowerPC only) apps are going to use more memory too, since they're running in emulation.

Thinine · Jan 30, 2007, 10:42 PM

mduell, that's executable size, not memory size.

Catfish_Man · Jan 31, 2007, 01:39 AM

Originally Posted by Thinine

mduell, that's executable size, not memory size.

No, codesize is in memory as well. That said, inlining a bunch of functions and unrolling a bunch of loops is far more likely to negatively impact cache behavior than it is to have any noticeable effect on ram usage.

OreoCookie · Jan 31, 2007, 06:30 AM

First of all, native Intel apps tend to use more memory. For instance, my ProBook with 1 GB felt slower at times than the PowerBook with 1 GB -- because the same apps need more memory.

As soon as you start a PowerPC app, memory usage goes way up. Rosetta makes a big difference in my experience, my ProBook (I've added another GB in the meantime) runs much smoother using only native Intel apps.

TheSpaz · Jan 31, 2007, 11:17 AM

Originally Posted by OreoCookie

First of all, native Intel apps tend to use more memory. For instance, my ProBook with 1 GB felt slower at times than the PowerBook with 1 GB -- because the same apps need more memory.

As soon as you start a PowerPC app, memory usage goes way up. Rosetta makes a big difference in my experience, my ProBook (I've added another GB in the meantime) runs much smoother using only native Intel apps.

Thank you. I didn't know that Intel Apps used more RAM than Apps running on a PPC Mac. I understand Rosetta uses a lot of RAM but, I hardly EVER have any PPC Apps running and I try not to use old Apps that are not updated for Intel but, there are a couple of games that I run in Rosetta that don't run too bad.... Medal of Honor, Max Payne, Alice, and Call of Duty all run pretty nice for running under Emulation. I love how Rosetta is completely transparent (meaning you don't have to watch it launch in the background like Classic) and the speed of Rosetta is incredible and I bet it will be even faster in Leopard.

macintologist · Feb 1, 2007, 07:17 PM

I think Mac OS in general will use more RAM the more you have.

On my old Powerbook with just 512MB of ram Safari will only use something like 40 MB or so. Whereas on my 2GB of Ram intel iMac it uses up to 300MB. RAM is like 10x faster than hard disk though so guess which computer runs faster?

Catfish_Man · Feb 2, 2007, 01:13 AM

Originally Posted by macintologist

I think Mac OS in general will use more RAM the more you have.

This is certainly true; there was a discussion on #webkit recently about how WebKit scales certain cache sizes based on the amount of ram installed.