[jack_napier]

OK, let me make a few points:

#1: Having 8 CPUs does not make you eight times faster than someone with one. How multi-threaded does a non-server need to be? I do development work all day; including running development instances of application servers. I don't really see that often a situation where more CPUs than the two I have would help. For running a single-threaded application (which most are), YES, a 3.2GHz Core 2 Duo will be faster than 8 Xeons. And for right now, your applications like a word processor or a web browser are...you guessed it, single threaded.

#2: I put together my PC right after the Core 2 Duos came out. There were no quad core machines, or dual quad core machines. I was speaking relative to the timeline. I didn't make that at all clear.

#3: IO, the hard drive is usually the speed bottleneck, not the CPU. Apple has the standard drives or the expensive SCSI option. I have 10k RPM SATA drives. They're noticably faster than the standard; sometimes just as fast as the SCSI options. But certainly cheaper.

#4: Overclocking.

[Spktyr]

“For running a single-threaded application (which most are), YES, a 3.2GHz Core 2 Duo will be faster than 8 Xeons. And for right now, your applications like a word processor or a web browser are...you guessed it, single threaded.”

A Core 2 Duo at 3.2 gHz is not faster than a Xeon at 3.2gHz.

“#3: IO, the hard drive is usually the speed bottleneck, not the CPU. Apple has the standard drives or the expensive SCSI option. I have 10k RPM SATA drives. They’re noticably faster than the standard; sometimes just as fast as the SCSI options. But certainly cheaper.”

Outdated info, as is to be expected from a PC user, I suppose... Apple uses SATA in all currently shipping products, with the exception of the MacBook Air. In addition, the Mac Pro and the servers have the option of SAS 3GB drives at *15,000* RPM, which makes your 10K drives look, well, slow.

[antiRepublicrat]

#1: Having 8 CPUs does not make you eight times faster than someone with one. How multi-threaded does a non-server need to be?

1) More and more programs are becoming multithreaded. Even the small shareware video apps on Mac will use any processors you have.

2) Running development instances of application servers can really use multiple cores. VMWare gives each instance the option of how many cores it wants to use.

3) It can help even a single-threaded application. Accessing some OS X libraries, for example Core Animation, automatically spawns another thread even if the application doesn't know about it.

4) The cache is the key to the high performance of the Intel Core line. A Core 2 Duo normally comes with 4 MB L2 cache. The Xeon line in the Mac Pro comes with 12 MB L2 cache, 6 MB per pair of cores, 50% more cache. Even on a per-core basis it should be faster.

5) Xeons also tend to run on a faster bus.

6) However, they may be slower for certain latency-intensive benchmarks. This is because of the FB-DIMM memory modules have a much higher bandwidth at the expense of latency.