Jason Wolf of Powerlogix sent a long mail with comments on his tests with 8GB of RAM installed in a PowerMac G5 1.8GHz model. (Later in the comments notes a 1.6GHz, which has only 4 dimm slots so I wrote to ask if that was a typo.) He noted some problems depending on the brand of RAM used but didn't disclose the mfr of the memory yet.
(copy of Jason's mail follows)"
For the forum:
I really should read through the other forums to check for repeat or
redundant info here, but I wanted to put this info up asap and get some
feedback from this great forum.
I recently added 8GB to a G5 Single 1.8GHz Mac. I was very excited with this
test and went to the system preferences to hunt for *any* memory control
panels or control - I found none. I wanted to create a RAM disk and started
to think that I could maybe go into classic - but nope - that feature of the
memory control panel in OS 9 does not work through classic. Okay, I
thought... how do I test this chunk of memory?
I continued to hunt for any and all memory control utilities or panels
within OS X and I couldn't believe that there isn't any. At least I
couldn't find any... so what are you supposed to do with 8 GB of RAM once
it's in there... I could always allocate chunks to my apps - sure FCP loves
a huge chunk of RAM allocated for it, but does anyone know how to create a
RAM disk in OS X? I want to keep it native code - perhaps Panther will
offer such control over the memory.
I tested two brands of memory - I don't have the liberty to name them here -
but one set of Memory Modules would not boot up without the stock memory
installed in slots 0. I found this strange and unacceptable and so I
installed the "Brand 1" memory into slot 0. It booted up - only after I
reset the PMU from the mobo. Okay, maybe it just needed a little reset -
but to my dimise I got a kernal panic while the progress wheel was spinning.
With "Brand 1" I was only able to get 6.5 GB of memory installed - the only
way to boot was with the stock 256MB modules in slots 0.
So, on to "Brand 2". This memory was quick - it just felt good. I was able
to stack it up to 8GB - insalling 2 GB's at a time... all the way up to
8GB's. So now that I had this memory installed - this is what I did to test
it:
XBench: XBench seems to only recognize 2GB of RAM. Once I was past that
(after the first install) the memory tests from XBench remained the same
(around 200.00).
Let 1K Windows Bloom: I don't know why, but I love this bench mark... it's
simple and fast... after installing 2GB - it didn't make a difference how
much more I installed - it ran 20 - 21sec. consistantly. With the stock 512MB RAM installed it pulled a 19 sec. run...
Photoshop: I ran OWC's plugin bench test script. With the stock memory
only it finished the test in 4min 45 sec. With the full 8 GB installed and
1GB allocated to PS, it pulled a 3min 14 second run... that's about 25
native plugins instantiated and executed folks!
Quicktime: This one's good and I couldn't believe it. I had 8 Quicktime
movies at DV quality - 720 x 480 - 4 minutes long - 450MB in size. I
launched these 8 movies and started them looping in different places in the
timeline - all 8 movies playing at the same time at different with different
sizes. The G5 opened these up no problem... no hiccups or glitches when
switching inbetween movies... even when resizing. I left the default memory
setting set the way it was. While these 8 movies where playing, I went back
to the finder and selected all 8 movies. I then duplicated all of them...
that's 3.8GB worth of file duplication while the files where accessed and
played with Quicktime... again, no hitches with the movies playing back in
the back ground - maybe a dropped frame here and there... but still very
impressive. After the duplication was finished (took about 3 minutes or so)
I closed QT. ZIP ZIP ZIP - all the movies closed like dominos - one right
after the other - no hesitation. Then I went back to my directory which now
had 16 DV quality movies in it... I selected all of them and opened them up
- boom boom boom - one right after the other, no problem... then I started
to play and loop them one right after the other... I doubled the size on a
couple (to 1440 x 960) and let them all play... it was struggling just a
little...
while these were playing, I went to the OWC photoshop benchmark and started
it... the progress bars on the plugins never stopped or hesitated... it
plowed right through them. While this was going on I launched iTunes and
started ripping a cd - the QT movies at this point were hiccuping and
stuttering - but the memory allocation was only like 36MB... while this was
all going on I ran "Let 1K Windows Bloom" and still pulled a 21 second
run... not to damn bad. I was very happy with all of this.
Question: How would you test 8GB of RAM in the G5's?
Another Question: Does any one know how to create a RAM disk? I would love
to install Photoshop on a RAM disk and time the OWC bench mark...
(Two readers sent a note in reply to Jason's question about an OS X compatible RAMDisk with a note that there's now an OS X compatible version (2.0) of Rambunctious.-Mike)
Until next time...
jsnwolf
G5 Memory Test 9/12/03
Memory Manufacturer: ___not public at this time___
System: Mac OS 10.2.7 shipped with 1.8GHz G5 processor (OS version and G5 model corrected)
The bullets below are individual steps. Second indented bullets cover results associated with the step above it. KP = Kernal Panics.
* = Attention to step or detail.
Test 1: Installed (2) 1GB modules in slots 0
. Launched 16 movies in QT. Each movie was DV Quality, 720x480. I
started each movie playing and looping.
. Launched Photoshop 7 and started the OWC bench test script.
*At this time Photoshop did not load a splash screen - just text.
Photoshop quit and shut down with no error, dialog box, or warning - just quit.
. Quit Quicktime and movies.
. Re-launched Photoshop
Kernal Panic
. Warm Reboot
. Launched Photoshop
No splash screen
Self Quit again with no dialog or error.
. Cold Reboot / Zapped PRAM
KP immediately on white Apple Screen.
. Cold Reboot / DID NOT Zap PRAM
KP immediately on white Apple Screen.
. *Reseated the Memory Modules
. *Booted into OS with no KP
. Launched Photoshop
*Splash Screen present but didn't load all the way
"This Program has unexpectedly Quit" dialog displayed
. Relaunched Photoshop
*No splash screen displayed, just text
"This Program has unexpectedly Quit" dialog displayed
. Relaunched Photoshop
*No splash screen displayed, just text
"This Program has unexpectedly Quit" dialog displayed
. Launched Quicktime Player
Played all QT movies, looped.
. Launched iDVD and iMovie and created sessions
It seemed as though the OS integrated software was not nearly as affected by
the memory modules as was Photoshop. Photoshop just refused to load or run
once this memory had its first Kernal Panic.
Test 2: Installed (2) Different 1GB modules in slots 0
. Boot -
Immediate KP
. Booted without Zapping the PRAM
*No Chime / No Video
. *Reseated the Memory and booted without Zapping the PRAM.
Got Chime and Video w/ immediate KP
. *Reset PMU on mother board
. Booted
*Chimed once although could not zap PRAM
Test 3: Installed (2) Different 1GB modules in slots 0
. Boot
Chime / No video
. shut down
Installed (2) 256 MB ____stock____ Memory Modules
Boot without Zapping PRAM - waiting- fine
Launched ps fine - ran stress
Thanks!
jsn
"
