[Timetheus]

If we've already discussed this to death, you have my apologies.

I bought a 1GB SO-DIMM of Gigaram PC2-5300 for my MBP off Newegg a couple weeks ago, and temporarily paired it with Apple's stock 512 DIMM, with the intent of replacing the stock DIMM with a matching Gigaram one. As luck would have it, however, Newegg is sold out of the product, and pulled it from their listings all together.

So here's my question, do I need to find a matching Gigaram stick to fully utilize dual channel (I've heard that it does, in fact, make a 8-9% performance boost)? Or, can I use another PC2-5300 DIMM at 1GB made by another brand and still take advantage of Dual Channel?

Here's what Apple has to say:

The MacBook Pro will run fine with either a single memory slot filled or with both memory slots filled with two unmatched memory sizes (such as a 512MB DIMM in one slot and a 1GB DIMM in the other).

However, if both slots are loaded with an equal amount of RAM (such as two 512MB DIMMs of the same type), you can take advantage of the system's dual-channel memory architecture for an additional performance boost. With a dual-channel memory interface, both banks of SDRAM can be addressed at the same time, enabling MacBook Pro to reach a memory throughput of up to 10.7 GBps.

By "Same type" does it mean brand or speed? My guess is speed, but I want to be sure. Do the timings you see in hardware test (the series of numbers in dashes) matter for dual channel, because those may not match between manufacturers, right?

If not, I may have a Gigaram SO-DIMM to sell so I can buy a different matched pair.

[SpaceMonkey]

Correct, it's size and speed that matter, not brand.

[Sophus]

I read somewhere a test showing that pairing RAM for MBP won't do much in terms of improving the performance. The reason is simply that the single bus will not get saturated as the CPU memory interfaces alone aren't capable (fast enough) to saturate the memory bus. As the MBP has its own dedicated VRAM for the graphics card the graphics card won't need to access the RAM either. The conclusion was that there is no true (or practical) benefit in pairing RAM.

On the other hand, the Macbook will benefit as it uses shared RAM for VRAM, so macbook useres should consider pairing RAM if they want better game/3d performance at high detail scenes that tax the memory.

Anyone remember where the article is?