Who is using more than 4 GB of RAM ?

ElDiabloConCaca said:
Hehe... I paid $180 for my first stick of PC100 128MB RAM to bring my total at that time to a whopping 256... hehe...
Click to expand...

Wow, I remember picking up the 16KB expansion module for a TRS-80, which was about half the size of my G4 tower and brought the total RAM up to a whopping 32KB =) And I'm in my 20s...
 
We had a Commodore Vic 20 that came with 8kb as standard. My dad added another 8kb by adding a cartridge the size of a VHS video into a slot on the top. We thought we were cool lol :) I too am in my mid 20's
 
I have 4 GB of RAM on each of my 1100 dual 2 Ghz G5's.

Oh wait, that's Virginia Tech! :p
 
Hehe... off topic a little, but while we're talking about pricing of technology, I remember my uncle purchasing the Chess cartridge for our Atari 2600 for $89 waaaay back in 1979!
 
You might wanna take a look at this: Photoshop memory test. Amazing how performance increases steadily up to 4 gig and only then remains constant. Photoshop sure is a memory eater! My PowerBook with a 1 gig memory limit suddenly looks really, really inferior... Thank god I don't have to juggle with 100+ meg Photoshop files every day :D
 
Can someone confirm/deny/show the calculations for the MAXIMUM amount of memory accessible by a 64bit computer? Some guy in business week said its 18 exabytes. Apple says its 8gb. but that (apple's story) doesnt make sense. the binary system doesnt work that way.
heres what i could work out. I ended up writing a small PHP for loop to do the math. I'll post the code and the result, if someone can please tell me if it's correct.
Code: 
$bit = 1;
for($pos = 1; $pos <= 64; $pos++)
	{
	$bit *= 2;
	echo $pos . " | " . $bit / (1024 * 1024 * 1024) . "Gb<br>\r\n";
	}
This gives you a final result of:
64 | 17179869184Gb
If you continue to reduce by 1024, you end up with 16 billion billion bytes, or 16 exabytes. which makes more sense since 4 and 16 are both binary values, but 18 is not. anyways. is this true? a 64bit cpu can address up to 16 exabytes of ram?
obviously osx isn't gonna deal with it, but its a HARDWARE capability, yes?
 
The processor may be 64 bits, this does not imply that it physically outputs 64 lines for adressing. The same way as the original MacPlus was limited to 4 MB because the 32 bit 68000 was only giving 24 address bit out of the chip.
 
Chevy, while that makes sense, that would mean the g5 only gives out 33 address bits out. thats right. 33. i doubt ibm/apple would develop a new 64 bit chip with 33bits of memory addressing. thats just plain stupid.
 
The chip itself may be able to access 8, 16, 18, or whatever EB of memory, but that does not mean the OS or any other software has been coded to take full advantage of it yet. Most stuff doesn't need that much anyway, so there's no functional capability yet, just technical/potential capability.
 
As i said, OSX obviously isn't going to be engineered to access 16 exabytes of ram. i was asking about the hardware capabilities of a 64bit cpu. given that its based on the Power4, the chip probably has no problem with more than 8gb of ram, its more likely to be the limit of the controller or the physical limit of the size of DDR chips...
 
Apple's specs are typically based on the maximum size of chips available at the time of release. I typically exceed the maximum RAM in a machine before it becomes a doorstop. When 2GB chips become available I wouldn't be surprised to see the actual limit on the G5 turn out to be higher than 8GB. However, Apple will keep it listed as 8GB, and only list their new model(s) as capable of more. It's a bit or marketing hype.

So there is definitely a limit in max DDR chip size right now. 1GB * 8 slots = 8 GB. Getting more than that is prohibitive in terms of physical size.
 
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