g5 quad ram allocations

phidelity · Oct 3, 2008

hello

i have a g5 quad which i have recently upgraded the ram to 8 gig, 2 sets of 4gb in matched pairs of 2gb simms of kingston ecc ram. my issue is no matter how much software i am running i cannot access more than a total of 4 gb, according to the activity monitor. my main use is cubase 4 (which is supposed to be able to access 4 gb max as of this current version) and other audio related programs. i also had numerous ram issues with this machine and had to send back ram from two other manufacturers.

my concern is that some of the ram is not being utilized by the machine and i am curious if there is a way to identify whether this could be possible due to some other hardware problem. i had the machine tested by a reputable apple tech but they did not test the machine with all the ram installed .. instead only tested with the standard issue ram from apple (one pair of 256 mb simms. is it possible that the motherboard is having issues with that task and if so how would i go about testing this?

thanks

LSDARBY · Oct 4, 2008

Yeah you can only have upto 4GB of RAM. It does say on the box and on all the spec sheets/manuals.

phidelity · Oct 4, 2008

LSDARBY said:
Yeah you can only have upto 4GB of RAM. It does say on the box and on all the spec sheets/manuals.

yes this i know but what i am having trouble with is : why my g5 cannot utilize all of the ram that is installed and shows up in the system profiler? and how do i figure out if there is a problem with the ram buss or what the problem is?

thanks for the response

LSDARBY · Oct 5, 2008

phidelity said:
yes this i know but what i am having trouble with is : why my g5 cannot utilize all of the ram that is installed and shows up in the system profiler? and how do i figure out if there is a problem with the ram buss or what the problem is?

thanks for the response

Because it only supports up to 4gigs of RAM it wont be able to read or utilize anything above that. Atleast thats what i assume.

phidelity · Oct 5, 2008

LSDARBY said:
Because it only supports up to 4gigs of RAM it wont be able to read or utilize anything above that. Atleast thats what i assume.

yes this is true but..

sorry for my poor communication. to be clear cubase will not access even 4 gig nor can i get this machine to access over that amount while running numerous other programs that are not part of the cubase umbrella (other synthesis, midi or audio programs that are not vst pluggins). which should mean they will access there own allotment of ram, correct?

so this is the premise of my concern. with all these programs running i don't seem to utilize the ram that i have available so how can i test why this is occurring.

thanks

phidelity · Oct 9, 2008

anyone with suggestions on this?

rman · Oct 9, 2008

My understanding is that the easier G5 can use up to 8GB of memory, whereas the later ones can use up to 16GB of memory.

The problem here is getting the system to allocate the 8GB of memory.

Just because an application can use a certain amount of memory, does not mean that it will allocate that amount.

Dustin · Oct 10, 2008

I read somewhere that since Leopard is 32Bit, it will only see 4GB of ram. When people run VMware Fusion and Vista, they can see the whole 8GB of Ram, due to Vista being 64bit. I found this on my searching to see if i can run an Imac with 6GB, or even 8GB or Ram.