Why laptops only 2 gigs?

Emrtr4

macrumors regular
Original poster
Feb 6, 2006
186
0
I was just wondering why all Apple laptops can only hold 2 gigs of memory.

Most pc makers offer 4 gigs of memory in their laptops, especially 17 inch computers.

It just strikes me that Apple has a desktop that holds the most memory in the world, but yet their laptops are faily low end.

Even if there are only 2 Dimm slots, there are such things as 2 gig memory modules. Also, there is no reason that the 17 inch does not have 4 Dimm slots.

Anyone know if it is possible to put 3rd party memory more than 2 gigs in a Macbookpro?
 

tipdrill407

macrumors 6502
May 26, 2006
373
0
I believe you need 64 bit processing or somefing to support 4 gigs of ram but I'm not sure. Also 2 gig ram sticks are usually "fatter" so they probably won't fit properly in the MB or MBPs.
 

apachie2k

macrumors 6502
May 23, 2006
408
5
was NYC...now MIAMI
tipdrill407 said:
I believe you need 64 bit processing or somefing to support 4 gigs of ram but I'm not sure. Also 2 gig ram sticks are usually "fatter" so they probably won't fit properly in the MB or MBPs.

that's what i heard...so maybe with the next update....we can see a @#$ load of ram!
 

Josias

macrumors 68000
Mar 10, 2006
1,908
1
tipdrill407 said:
I believe you need 64 bit processing or somefing to support 4 gigs of ram but I'm not sure. Also 2 gig ram sticks are usually "fatter" so they probably won't fit properly in the MB or MBPs.
Research my friend, research:)

32 bit processors support up to 4 GB of RAM.
The PowerPC 970/970FX, also known as the G5, supported up to 64 TB (64.000 GB of RAM). I dunno what other 64-bit processors support.

The 2 GB SO-DIMMS are smae size as others, but are like $2500. That's why.;) Of course, the 2 GB dimms for the new iMac are $750, so I guess the next gen. MBP will support 4 GB.
 

NextTuesday

macrumors member
Aug 31, 2006
86
0
Cork, Ireland
Josias said:
Research my friend, research:)

32 bit processors support up to 4 GB of RAM.
The PowerPC 970/970FX, also known as the G5, supported up to 64 TB (64.000 GB of RAM). I dunno what other 64-bit processors support.

The 2 GB SO-DIMMS are smae size as others, but are like $2500. That's why.;) Of course, the 2 GB dimms for the new iMac are $750, so I guess the next gen. MBP will support 4 GB.
This is why I want a 12-inch PowerBook G5 with 32TB of RAM (64 is too much in my opinion :p )
 

rtharper

macrumors regular
Sep 6, 2006
201
0
Oxford, UK
Josias said:
Research my friend, research:)

32 bit processors support up to 4 GB of RAM.
The PowerPC 970/970FX, also known as the G5, supported up to 64 TB (64.000 GB of RAM). I dunno what other 64-bit processors support.
32 bit PROCESSORS can address up to 4 gigabytes, it's true. This is because it can address memory locations from 0 to 2^32 (4,294,967,296 bytes). The same formula is true for all 64-bit processors; they can address from 0 to 18,446,744,073,709,551,616. I believe this number is actually sixteen exabytes.

The limitations for memory have often come from other factors in the platform (motherboard chipsets and hardware limitations). Even 32bit motherboards did not support 4 gigabytes in the beginning of the 32-bit era. We've reached the mathematical limit for 32-bit registers, but chipsets and hardware design will take a while to reach the 64-bit limit.
 

steve_hill4

macrumors 68000
May 15, 2005
1,856
0
NG9, England
aussie_geek said:
It is crazy now...Wait 10 years - that will be like 64MB... ;)


aussie_geek
I concur. Never say this will be enough for me, or state you'll never need any more.

If I can think of 600GB external storage as being plenty for my needs over the next few years, then fill it within months, I would never anticipate anything again. Prepare for tomorrow, as it is only a day away.
 

steve_hill4

macrumors 68000
May 15, 2005
1,856
0
NG9, England
Josias said:
Research my friend, research:)

32 bit processors support up to 4 GB of RAM.
The PowerPC 970/970FX, also known as the G5, supported up to 64 TB (64.000 GB of RAM). I dunno what other 64-bit processors support.

The 2 GB SO-DIMMS are smae size as others, but are like $2500. That's why.;) Of course, the 2 GB dimms for the new iMac are $750, so I guess the next gen. MBP will support 4 GB.
I checked crucial for a Dell XPS that supported 2GB sticks to see for myself. 1GB was $150, 2GB was $1500. Never realised it was quite so much of a difference.

Beside that Apple at $750 is actually a bargain.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
A function of how Apple set up their 32-bit address, and did the split between the OS and the hardware addresses.

In the 64-bit Merom upgrade, you will get an extra gigabyte. Which makes the problem a chipset problem. And we get nearly the same memory as PC users on the same chipset.

You'll be able to put in 3GB of memory and use it all or 4GB of RAM and use 3GB. Your choice. ;)

Basically Merom will take the current OS out of the equation, and put Intel on the hook for the silly 3GB limit right now.

---

When we get the new chipset, you should be able to have 8GB while the desktop version of the chipset is at 16/32GB.

But remember these 64-bit chips are still limited to a max of 36-bits of physical RAM, so the chipset isn't too far behind the curve. And the MacPro at 32GB is nearly maxed out.

64-bit registers, 48-bits virtual memory, 36-bit physical memory, & a 32-bit chipset = 3GB on a Merom MacBook.
 

zwida

macrumors 6502a
Jan 5, 2001
587
0
NYC
CoMpX said:
64TB of RAM is freaking insane! :eek:

For God sakes, even 64GB is ridiculous!
Ahhhh, but imagine the RAM disk that you could get going...

I've been toying with installing Photoshop in a RAM disk when my new machine arrives. I'm sure there's a reason why this is a bad idea, but I gotta try it.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
While the 32-bit G4 had been tweaked with a 36-bit memory addressing mode (giving a theoretical 64GB rather than 4GB memory ceiling), the 970 can handle more memory than any Power Mac G5 owners are likely to install. The processor matches its 64-bit data path width with a 64-bit virtual memory-address range -- supporting a mind-blowing 18 exabytes or 18 million terabytes -- along with a more than ample 42-bit or 4TB real address range. (By contrast, AMD's Opteron has a 48-bit virtual and 40-bit physical address space.)
So the opteron is at 1 TB, the Meron at 64GB (and still not quite a full 64-bit address cpu, since it is limited to 48-bit virtual).

But yes, the PPC970 was insance in its capabilities -- sort of sucks we never even saw the G6 and all the future Gx series that would have followed based on future full Power Series chips. :(

But if you think about it, the 48-bit virtual memory CPUs are getting near EOL since RAID clusters are rapidly growing -- so a 256TB scratch disk isn't that far off or silly.
 

n-abounds

macrumors 6502a
Mar 6, 2006
562
0
appleintelrock said:
Let's throw away our hard drives and buy 100 GB ram sticks for 1 millions bucks each! yay
Well, with that much demand, I'm sure the prices would decrease fairly rapidly :D

How does one make a RAM disk? Just have few applications going at once?