Following up on my previous comments on the new Nehalem Mac Pro—
Here’s one staggering drawback to the new (March 2009) “Nehalem” Mac Pro: memory cost. An 8-core machine can be a lot less expensive than a 4-core machine, read on for more on that paradox.
There are eight slots for memory, and 16GB as 8 X 2GB is an inexpensive $300 by comparison to the cost of the Mac Pro itself: less than 10% of the base price of the least expensive 8-core model.
Now here’s the rub: 16GB of 2GB modules is $300, but 16GB of 4GB modules is about $2500. That’s $5000 for 32GB! And it’s not just Apple’s price, it’s OWC’s price. The parts availability is just not there yet, so costs are outrageous. How long will it take for the price to come down? If the first Mac Pro is any guide, 9-12 months.
In short, you can get a new Nehalem Mac Pro and spend $5000 for 32GB of memory for an anal-puckering $11000 system (2.93GHz). Or you can get a refurbished prior-generation 3.2GHz model and 32GB memory for about $5100. In other words, you can get two of the previous-gen models with 32GB each and have money left over for eight fast 1TB hard drives!
Now that’s some stimulus where the sun don’t shine.
What about the 4-core vs the 8-core model when you need more than 8GB memory?
The crippled 4-core model has only 4 slots—going beyond 8GB therefore requires 4GB modules at 8X the cost per GB of 2GB modules.
You can get an 8-core model with 8X2GB for about $3600 or a 4-core model with 4X4GB for about $5000 (and that’s assuming the 4-core model even works with 4GB modules). Sometimes decisions are easy: if you need more than 8GB of memory, the 8-core model is far less expensive than the 4-core model! So shun the 4-core model. It’s a lousy investment if your needs ever change.