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View Full Version : The 4 Gb RAM thing with G5s




leekohler
Dec 15, 2006, 02:25 AM
I've heard that G5s (especially dual-core/processor) really fly with 4 Gb RAM. Does anyone have one with this much RAM? If so, is it really worth the upgrade? I have dual-core G5 with 3.5 Gb RAM. It's great, but I do think it feels a bit choked at times. I would like to give it another Gig. What do you guys think? Worth it?



eXan
Dec 15, 2006, 02:56 AM
What do you use it for?

No, I dont think it would be worth adding extra 512 MB since you laready have impressive 3.5 GB. Matching RAM doesnt really improve performance on PPC Macs.

BTW, every machine flyes with 4 gb RAM, if you can use all that memory of course ;)

leekohler
Dec 15, 2006, 10:16 AM
What do you use it for?

No, I dont think it would be worth adding extra 512 MB since you laready have impressive 3.5 GB. Matching RAM doesnt really improve performance on PPC Macs.

BTW, every machine flyes with 4 gb RAM, if you can use all that memory of course ;)

I'm an art director. I use it for photography and graphics, some video editing. It gets pushed hard, trust me. As for RAM not improving performance of PPCs, simply not true. I noticed a huge difference between 1 Gig and 3.5. I've just heard in several places that 4 is the magic number for G5s and was wondering what others' experiences have been.

Eidorian
Dec 15, 2006, 10:27 AM
Check your RAM usage and page outs in Activity Monitor under normal usage. I doubt the extra 512 MB is going to make much of a difference.

If you're using matching pairs of RAM you're not going to see much of a gain besides the extra 512 MB when you hit 4 GB.

CanadaRAM
Dec 15, 2006, 10:29 AM
Check your RAM usage and page outs in Activity Monitor under normal usage. I doubt the extra 512 MB is going to make much of a difference.

If you're using matching pairs of RAM you're not going to see much of a gain besides the extra 512 MB when you hit 4 GB.

Using matching pairs is mandatory in the PowerMac G5s...

Eidorian
Dec 15, 2006, 10:30 AM
Using matching pairs is mandatory in the PowerMac G5s...I know.

leekohler
Dec 15, 2006, 11:00 AM
Check your RAM usage and page outs in Activity Monitor under normal usage. I doubt the extra 512 MB is going to make much of a difference.

If you're using matching pairs of RAM you're not going to see much of a gain besides the extra 512 MB when you hit 4 GB.

Thanks- and yes, I use all matching pairs. :)

RichP
Dec 15, 2006, 11:31 AM
I have 6GG in my G5 2.7 (I purchased it used and it was loaded up from previous owner) Note that pshop has a RAM max of 3GB or so; you may see more of an overall boost by getting some highspeed harddrives, just as the WD Raptor (which I also have, and REALLY speeds things up nicely)

jtt
Dec 15, 2006, 06:37 PM
Using matching pairs is mandatory in the PowerMac G5s...

So adding two 1 gig sticks with the factory 512 is a no no?

mjstew33
Dec 15, 2006, 06:44 PM
So adding two 1 gig sticks with the factory 512 is a no no?

No.

Like, you have to use matching pairs, as you can't have one stick of 1GB just sitting there, it has to be, for 512MB, 2 256MB sticks, 1GB 2 512MB sticks, 3.5GB... 2x 1GB, 2 512MBs, and 2 256mbs.

Get it?

eXan
Dec 15, 2006, 09:13 PM
As for RAM not improving performance of PPCs, simply not true. I noticed a huge difference between 1 Gig and 3.5. I've just heard in several places that 4 is the magic number for G5s and was wondering what others' experiences have been.

Uhh maybe you have to re-read my post more attentively...

I said that extra 0.5 GB of RAM wouldn't mkae much of a difference, since you already have 3.5 GBs. Matching RAM (installing them in pairs) did not really help increase performace on PPC-based Macs. See benchmarks at barefeats.com. The gains are usually 0-2%.

And there's no "magic" number of RAM on any machine. If you heard that 4 GB is it in PMG5, it must be 4 1GB sticks, which in theory will give you maximum performance, if you're on a PM with 4 ram slots. This 4 1 GB sticks is also paired RAM.

TyPod
Dec 15, 2006, 09:53 PM
4GB would be very nice, but I think your 3.5GB is more than fine. If you have the money and really want the extra 0.5GB, go ahead and get it, if not, you will be totally fine with 3.5GB.

Fredou51
Dec 15, 2006, 10:02 PM
But why would you just go up 512MB? An upgrade to 5.5GB would be a big difference. Or is your revision of G5 limited to 4GB?

Frederic

hayduke
Dec 15, 2006, 10:13 PM
My impression is, that if you don't *know* if you need 4GB ram then you don't need 4GB of ram. I know what I need because I carefully monitor the Activity Monitor or Top and I can see if what I am doing is memory limited or not. If you are not memory limited then the extra 512MB is unlikely to help much. Make sense?

4JNA
Dec 15, 2006, 11:05 PM
g5 dual 1.8 rev b with only 4 slots, and have 4gb (4 x 1gb) here. photoshop, dreamweaver, flash, firefox, itunes open all the time, and still have decent performance. can't imagine that 3.5gb would be any different though based on what i see in the activity monitor as i rarely get over 3gb.

leekohler
Dec 16, 2006, 04:28 AM
But why would you just go up 512MB? An upgrade to 5.5GB would be a big difference. Or is your revision of G5 limited to 4GB?

Frederic

No I bought the last rev G5. I can get 16 Gigs in this baby. :) So yes, I should take it as high as I can go I guess. It's just that when burning DVDs, it maxes the RAM and then some. I should have said that earlier. Thanks for all the replies! :)

MacRumorUser
Dec 16, 2006, 05:22 AM
for anyone wondering if they need more ram.

Activity monitor, under memory look at the page in/outs

If you have a lot of page outs (the number after / ) then yes memory will help

If you have /0 page outs then NO you dont need more memory as you are not using all the memory you have.

Simple to check and a far better indicator than anyone here can tell if you need more memory as everyones usuage is different.

I have 3GB in my MacPro and so far havent had a page out even though I'm using photoshop, entourage, painter IX.5 (all not universal), but I'm sure others will be using far more memory than me.

macg4
Dec 16, 2006, 11:04 AM
well at that point the extra 512mb ram will not make much dfference...although i recently went from 1gig to 1.5 gig in my pm g5 and i can feel the difference in the extra 512mb

Keebler
Dec 16, 2006, 11:12 AM
hi lee,

if i were you, i would upgrade your video card. i would think it would help with the graphics big time. you've got enough ram.

that's what i've heard before.

leekohler
Dec 16, 2006, 01:27 PM
hi lee,

if i were you, i would upgrade your video card. i would think it would help with the graphics big time. you've got enough ram.

that's what i've heard before.

Good thought! Thanks.

eXan
Dec 16, 2006, 11:50 PM
Good thought! Thanks.

Heh, the new videocard will make zero difference in 2D apps you work with. If you really want to waste some money, get a bigger monitor, or an iPod

CanadaRAM
Dec 17, 2006, 03:30 AM
Uhh maybe you have to re-read my post more attentively...

I said that extra 0.5 GB of RAM wouldn't mkae much of a difference, since you already have 3.5 GBs. Matching RAM (installing them in pairs) did not really help increase performace on PPC-based Macs. See benchmarks at barefeats.com. The gains are usually 0-2%.

I hate to flog a deceased equine, but the machine in question is a PowerMac G5, installing in pairs is the only option, there is no "if you install in matching pairs then..." or "0-2%" comparison with non-paired RAM because you can't install a single.

If you are saying there is no advantage to matching RAM across quads, that is, identical RAM in two matching pairs, then that is true, there isn't.

If you are referring to the relative performance of 128-bit access in the the first generation iMac G5 by installing a matching pair, that is true but irrelevant to the PowerMac G5 because the architecture is totally different.

Kernow
Dec 17, 2006, 03:47 AM
I have a dual 2.0GHz G5 with 4GB ram, and it has been plenty fast enough for anything that I have thrown at it. I mainly use it for audio production, running Logic and Live simultaneously (and occasionally Reason too), both for recording and mixing. I couldn't say whether it was significantly faster than 3.5Gb as I've had this configuration from the start, but it has run wonderfully so far.

eXan
Dec 17, 2006, 07:30 AM
I hate to flog a deceased equine, but the machine in question is a PowerMac G5, installing in pairs is the only option, there is no "if you install in matching pairs then..." or "0-2%" comparison with non-paired RAM because you can't install a single.

If you are saying there is no advantage to matching RAM across quads, that is, identical RAM in two matching pairs, then that is true, there isn't.

If you are referring to the relative performance of 128-bit access in the the first generation iMac G5 by installing a matching pair, that is true but irrelevant to the PowerMac G5 because the architecture is totally different.

I know that the discussion is about PMG5 and I didnt say anything about iMac G5.

You say that I can not, for example, install 3 1GB sticks in a PMG5? Does it has to be 2 1GB's and 2 512 MBs?

scottlinux
Dec 17, 2006, 08:41 PM
4GB of ram is currently the sweet spot with OS X. Because of the way OS X handles virtual vs. physical ram, there is a diminishing returns with more than 4GB of ram. Even with lots of ram over 4GB, OS X keeps using more and more virtual ram rather than actual physical ram- getting worse and worse. Lots of Logic users have noticed this. Hopefully this will be fixed with 10.5.

Still better than any windows machine could possibly dream of doing.

MacsRgr8
Dec 18, 2006, 01:07 PM
I always look into /var/vm/, and count the swapfiles to find out if I need more RAM.
If, after regular use, there are two swapfiles (swapfile0, and swapfile1), then the Mac could use more RAM.
swapfile0 is always present, but a 2nd (or 3rd) swapfile is only created when your Mac is using diskspace for RAM. If it only appears occasionally (after playing some heavy games orso), I wouldn't bother, but if multiple swapfiles are created after normal use, then I would recommend adding extra RAM.

bearbo
Dec 18, 2006, 01:12 PM
4GB of ram is currently the sweet spot with OS X. Because of the way OS X handles virtual vs. physical ram, there is a diminishing returns with more than 4GB of ram. Even with lots of ram over 4GB, OS X keeps using more and more virtual ram rather than actual physical ram- getting worse and worse. Lots of Logic users have noticed this. Hopefully this will be fixed with 10.5. wouldn't that be that Logic cant do with more RAM (altho i dont see why), not OS X can't do with more ram?
i dont know, someone must know about this... but it just doesn't make sense for OS X to throttle at 4GB



Still better than any windows machine could possibly dream of doing.

what the hell does this have anything to do with a machine of any hardware configuration running Windows?

scottlinux
Dec 18, 2006, 08:38 PM
wouldn't that be that Logic cant do with more RAM (altho i dont see why), not OS X can't do with more ram?
i dont know, someone must know about this... but it just doesn't make sense for OS X to throttle at 4GB

what the hell does this have anything to do with a machine of any hardware configuration running Windows?

No- Logic can only handle up to 3GB of ram internally. Users using lots of VST and AU plugins that load memory-hungry samples have noticed the diminishing returns with OS X with more than 4Gb of ram. There is a 4GB issue with OS X. People who go from a 4GB system to a 5, 6, or 8+ GB system have noticed this.

It is somewhat unofficially documented all over this forum:

http://www.vsl.co.at/forum/index.php

as well as in the audio community in general.


If you are a windows user today, you are limited to 3GB max, with the 3GB switch. So OS X currently handles memory better than windows, but when everyone (windows, OS X, Linux, etc.) all goes to FULL 64 bit, the memory limitations will be long forgotten.

This is why audio people prefer macs. Because of the better handling of memory, an OS X machine can equal twice the computer of a PC. Plugins and such in a DAW take lots of memory.

This issue is not just restricted to audio users, FWIW:

http://forums.macrumors.com/showthread.php?t=261046

so CS3beta is a little slower than CS2 on my quadG5, and overall no significant difference between MacPro and G5 (expecially at the same clock speed, see previous posts). Waiting for Leopard and its 16bit (will CS3final address more of my 16Gb of RAM ?!!), this CS3beta is not really interesting for the time being at least in terms of speed as far as PPCs are concerned.

BuzWeaver
Dec 18, 2006, 09:03 PM
I'm an art director. I use it for photography and graphics, some video editing. It gets pushed hard, trust me. As for RAM not improving performance of PPCs, simply not true. I noticed a huge difference between 1 Gig and 3.5. I've just heard in several places that 4 is the magic number for G5s and was wondering what others' experiences have been.

Just depends on your particular needs. I sell systems to Video/Sound/Graphic Editing companies often and they typically want at least 4GB. I've sold two in the last two weeks with 16GB.

leekohler
Dec 19, 2006, 10:45 AM
Thanks for all the replies. They've been interesting and helpful.

disconap
Dec 19, 2006, 03:55 PM
Google "MenuMeters". I do graphic design and audio work, and I use MM to monitor RAM and processor usage on my G5; I very, very rarely hit my ceiling. In fact, working in PSD with an image that was around 700mb yesterday, I was only using 1750mb of my 2.5gb of RAM, and that included system, the open file in Illustrator, and mail/firefox/quicktime open.

In my experience with suping up my G4, the addition of a scratch RAID makes a much larger difference than the addition of RAM past the 1.5gb level (for the G5, i'd extend that to 2.0). I'll let you know if that's true with the G5 as well, as my PCI SATA set-up arrives on Friday so I can finally set my scratch disks and RAID up like they were in my last machine...

MaaseyRacer
Dec 25, 2006, 06:54 PM
I had a Dual Processor PowerMac G5, with 2GB of RAM. The difference between that and when I went to 4GB was like upgrading from my 1.8GHz DP to the 2.3GHz DP. Well worth it. The PPCs espcially the G5s love more memory. 4GB was the perfect amount for InDesign, Photoshop, and Final Cut when I had that machine. 6GB was not that big of a differnece, and 8GB was noticable, but 4GB was the best bang for the buck.

eXan
Dec 25, 2006, 07:57 PM
The PPCs espcially the G5s love more memory.

Really? I thought intels love more memory, especially that Xeon in Mac Pro :D


4GB was the perfect amount for InDesign, Photoshop, and Final Cut when I had that machine. 6GB was not that big of a differnece, and 8GB was noticable, but 4GB was the best bang for the buck.

How can you even live now, going from 8 GB to 2 GB RAM?! :eek:

southbark
Dec 26, 2006, 02:14 AM
Just be glad you do not have a windows pc you could put 16gbs and it would still only use 3gbs of the ram the other13gbs wouldnot even show up

eXan
Dec 26, 2006, 02:34 AM
Just be glad you do not have a windows pc you could put 16gbs and it would still only use 3gbs of the ram the other13gbs wouldnot even show up

Even with Windows 64 on a 64-bit processor? I doubt it

bearbo
Dec 26, 2006, 03:09 AM
wouldn't that be that Logic cant do with more RAM (altho i dont see why), not OS X can't do with more ram?
i dont know, someone must know about this... but it just doesn't make sense for OS X to throttle at 4GB

what the hell does this have anything to do with a machine of any hardware configuration running Windows?

No- Logic can only handle up to 3GB of ram internally.

No, but you said almost the samething as I did?

i think you are having logical problem :S



If you are a windows user today, you are limited to 3GB max, with the 3GB switch.


when was the last time you've used a windows based computer? if it's any where in the near past, you should've know that windows can support more than 3GB of ram just fine. i dont have data showing the efficiency comparison between windows and os x, but i know windows (for instance, XP 64bit) can do with more than 3GB of ram. saying "windows user today, you are limited to 3GB max" is ridiculous.

kenzbud
Dec 26, 2006, 03:57 AM
for anyone wondering if they need more ram.

Activity monitor, under memory look at the page in/outs

If you have a lot of page outs (the number after / ) then yes memory will help

If you have /0 page outs then NO you dont need more memory as you are not using all the memory you have.

Simple to check and a far better indicator than anyone here can tell if you need more memory as everyones usuage is different.

I have 3GB in my MacPro and so far havent had a page out even though I'm using photoshop, entourage, painter IX.5 (all not universal), but I'm sure others will be using far more memory than me.


I have a number of 93,739 for page outs. Besides the obvious fact that I do need more ram what does that number represent??

vohdoun
Dec 27, 2006, 04:10 PM
I have a number of 93,739 for page outs. Besides the obvious fact that I do need more ram what does that number represent??

When the Ram is filled up it starts using virtual memory and hard drive swapping if I remember correctly which is slower performance.

http://guides.macrumors.com/Talk:Enhancing_Performance_Of_Mac_OS_X

Or is it...

eXan
Dec 27, 2006, 08:14 PM
I have a number of 93,739 for page outs. Besides the obvious fact that I do need more ram what does that number represent??

94000 is not that bad. I usually have 200000+ page-outs after my Aperture sessions :D ;)

CanadaRAM
Dec 27, 2006, 08:51 PM
I know that the discussion is about PMG5 and I didnt say anything about iMac G5.

You say that I can not, for example, install 3 1GB sticks in a PMG5? Does it has to be 2 1GB's and 2 512 MBs?

Yes, that is exactly it. You CANNOT install single sticks or odd numbers of sticks. They MUST be pairs -- 2 x 1, 2 x 512 etc. It has always been thus - it is mandatory in the PowerMac G5 architecture.
Which is why I was trying to tell you (again), comparing pairs versus singles in a PM G5 is a non-functional argument.

Since you were insisting (repeatedly) otherwise, I thought you may have been mistakenly referring to iMac G5s which do not use a Dual Channel architecture and where there is a theoretical performance difference.

Where in reality, the reason was that you don't know the first fundamental thing about PowerMac G5 RAM. Which begs the question why you thought posting quasi-authoritative information was a good idea in the first place...

Even with Windows 64 on a 64-bit processor? I doubt it

"A Windows PC" - I think with a 32-bit majority of roughly 99.999% in the non-server Windows world, that southbark can be allowed that assumption.

eXan
Dec 27, 2006, 09:01 PM
Yes, that is exactly it. You CANNOT install single sticks or odd numbers of sticks. They MUST be pairs -- 2 x 1, 2 x 512 etc. It has always been thus - it is mandatory in the PowerMac G5 architecture.
Which is why I was trying to tell you (again), comparing pairs versus singles in a PM G5 is a non-functional argument.

Since you were insisting (repeatedly) otherwise, I thought you may have been mistakenly referring to iMac G5s which do not use a Dual Channel architecture and where there is a theoretical performance difference.

Where in reality, the reason was that you don't know the first fundamental thing about PowerMac G5 RAM. Which begs the question why you thought posting quasi-authoritative information was a good idea in the first place...

Hey, hey! No need to get mad! :)

I was wrong, but I never owned a PowerMac G5!

Still, it seems strange that PM will only accept paired RAM. Is this the only Mac that behaves this way? :eek:

MaaseyRacer
Dec 27, 2006, 10:02 PM
Really? I thought intels love more memory, especially that Xeon in Mac Pro :D




How can you even live now, going from 8 GB to 2 GB RAM?! :eek:

My G5 was way more RAM hungry than my MacBook Pro. And I am surviving the 2GB of RAM thing alright. I am waiting for Mac World to see what is next for me in terms of a desk top.

CanadaRAM
Dec 27, 2006, 10:29 PM
Still, it seems strange that PM will only accept paired RAM. Is this the only Mac that behaves this way? :eek:

MacPro, XServe G5, XServe Xeon

Going back a few years:
Kits of 2: Plus, SE, PowerMac 6100, 7200, 8100, LCII, LC, Classic II, Color Classic, Workgroup Server 8150, 8550
Kits of 4: SE/30, Mac II, IIx, IIfx, IIcx, Mac IIci, IIsi, IIvx, Quadra 700, 900, 950
and their various Performa variants

O and A
Dec 27, 2006, 10:38 PM
I have a dual 2ghz g5 with 8 slots at work I have 3.5 gigs of ram.

I use photoshop with 100mb files, quark, itunes, illustrator, safari, instant messenger, mail, word, and sometimes indesign all open at the same time.

I don't go over 3 gigs unless i have several large files open with alot of history in photoshop.

I'm curious to see what the next revision of the mac pro holds as we are looking to get another fast machine. Bluray would be nice but i'm really looking forward to 3ghz quad with 4 gigs of ram for the price of that 2.6ghz quad. Of course it would be nice if adobe would move quicker with CS3

eXan
Dec 28, 2006, 02:33 AM
MacPro, XServe G5, XServe Xeon

Going back a few years:
Kits of 2: Plus, SE, PowerMac 6100, 7200, 8100, LCII, LC, Classic II, Color Classic, Workgroup Server 8150, 8550
Kits of 4: SE/30, Mac II, IIx, IIfx, IIcx, Mac IIci, IIsi, IIvx, Quadra 700, 900, 950
and their various Performa variants

:eek: :eek: :eek: