So what's the buzz about the new eight core Macs vs. the four core tower?
I've been trying to figure this out recently as I am about to buy myself a new tower.
No, working for Apple doesn't help as much as you might think. :biggrin:
Seems the price difference requires thinking about it. And wondering about the future.
The answer is more complicated than your question. People buzz about perceived capabilities of "more is better", but that isn't always the case. You have to study the entire architecture to look for limiting factors and bottlenecks, and also operational characteristics.
For example, some folks think more RAM is better, but that's not true. I can get better results from 4 GB of match-paired RAM in a system than 5 or 6 GB of unmatched RAM.
Another consideration is the ability of the operating system to consume available features of the hardware. Apple typically does an excellent job here, as it controls both the platform and the equipment. Both Tiger and Leopard support 64 bit computing. However, you may see a performance degradation in Tiger if you run 32-bit and 64-bit applications simultaneously. Essentially, it has to change gears to accommodate the different addressing schemes of the applications. The result of these wasted processor cycles for internal switching is a delay in application performance. Leopard enhances 64-bit operation to address this problem.
Eight cores will process faster than four cores if you restrict your measurement to data already in the processor. Will you always run your CPUs at max capacity to extract optimum performance? Absolutely not. Each processor runs faster than the bus that feeds it. The advantage of multiple cores is to process disparate streams in serial rather than parallel operation.
So do you get enough of a performance boost to justify the price? That depends upon your application. I recommend looking at the
Mac Pro Performance page on Apple's site. Note that only one case does the user receive a 3.1x performance benefit. Most of the increases are BELOW a doubling of speed from the baseline performance on older PowerPC architecture. The difference in performance between 4 core and 8 core (where noted) is about a .5 increase. Additional processors in a similarly equipped computer yield diminishing returns.
You'll get the best performance with 8 cores and max ram. If money is no object, go for it. If you're like the rest of us, you'll get more bang for your buck with 4 cores and more (matched) RAM.
