128MB SDRAM vs. 256MB SDRAM ???

SDRAM (Synchronous dynamic random access memory) is simply a more specific nomenclature to what most people just simply refer to as RAM. It's the type of solid state RAM used most commonly in personal computer applications.

http://en.wikipedia.org/wiki/SDRAM
(As you can see, the DDR2 RAM used for system memory in the MBP is also a type of SDRAM)

What you're asking about specifically is the dedicated memory used only by the graphics subsystem in the Mac Pro. As you know well by now, you can order a machine that has either 128 or 256 MB of dedicated video RAM. Unless you plan on doing heavy work (think more along the lines of professional work) in graphics, photo editing, digital film or the like, 128MB should suit your needs. This memory is not upgradeable, so if you even think you might want to do some of the things listed above, you should spend the extra $600 and future-proof the computer.

Bear in mind that you'd not be paying an extra $600 for 128MB more video RAM. You're also paying a price premium for the top of the line 2.33Ghz Core 2 Duo chip Intel offers.

I think you are confusing SDRAM with VRAM. The 2.16 GHz MBP's video card has 128 MBs of VRAM, whereas the 2.33 GHz MBP's video card has 256 MBs of VRAM. All the MBP C2D models support a maximum of 4 GBs of SDRAM. If you buy the low-end model it comes with a single 1 GB RAM module. You can install an additional 1 GB module on your own for around $120.00 plus S/H. The high-end model comes with 2 GBs of RAM (2 - 1 GB modules.) The differences between the two are fully detailed here.

Kappy,

I don't think the Core 2 Duo MacBook Pro systems support a full 4 GB of RAM, does it? I thought I read somewhere that even when 2x2GB sticks were put in, only 3GBs was recognized.

I'm pretty sure I've heard (read) Kappy harping on about 4GB of RAM being supported by the MBP CD, when Apple state 2GB for the MBP CD and 3GB for the MBP C2D in other threads.

This is apparently a restriction in the Intel chipset, from what I have read online, as opposed to an Apple limitation. Apple state clearly the maximum supported memory, so anybody claiming otherwise, may be mistaken or know something the manufacturer doesn't.

The C2D MBPs support up to 4 GB of RAM. However, as Apple has stated, most of the last GB is being used to map various system operations so that only a few MBs of it would actually be usable. Thus, the suggestion that 3 GBs is the maximum "usable" RAM even were 4 GBs installed. See the following:

November 4th, 2006 -- More on 3GB Memory Limit on MacBook Pro (Core 2 Duo): Apple states on their memory expansion page that "If you install a 2 GB SO-DIMM in both the bottom and top memory slots of the computer, the 'About This Mac' window and Apple System Profiler will both show that you have 4 GB of SDRAM installed. However, Activity Monitor and other similar applications will reveal that only 3 GB of SDRAM has been addressed for use by the computer." (This also applies to the iMac Core 2 Duo.)

Although the Intel 945PM chipset can physically handle 4GB of DDR2 RAM, there is the potential for "memory overlap" when more than 3GB of RAM is installed. Power PC users aren't used to this kind of limitation. Just say to yourself, "It's an Intel thing."

Of more concern to "speed freaks" is the loss of interleaving when you install unmatched pairs (as in the Apple factory's 1GB + 2GB config). Though not specifically included in Apple's comment's on the MacBook Pro's memory config, the iMac Core 2 Duo's documentation states that "because the memory in the two slots is configured as a contiguous array of memory, both SO-DIMMs must be the same size and type for the interleaving function to be used to improve performance."

But is the gain worth the extra $600+ pain? We hope to answer this in our upcoming Macbook Pro Core 2 Duo review.

Excerpted from article at Bare Feats.

I would sure like to know where you've seen these remarks you've attributed to me. However, for the record:

Core Duo MBPs support a maximum of 2 GBs of RAM. C2D MBPs can accommodate up to 4 GBs of RAM although only 3 GBs will be usable. See my previous reply for the full explanation.

Please, if you are going to attribute something to me I'd appreciate it that you be sure I actually said it as opposed to "pretty sure." Especially if you're going to accuse me of "harping."