On Fri, 11 Mar 2005 08:13:58 -0500
Michael <macallan18@earthlink.net> wrote:

> > Why not? MacOS recognized MP cards as far back as 8.6. Their MP API
> > was actually quite mature, even as early as the mid-90's. 
> My 2x604e UMAX Pulsar came with MacOS 7.6 and an additional CD with
> software to support the 2nd processor and a bunch of demos, featuring
> a very fast fractal renderer that ran on both CPUs :)
 
With 8.6, Apple implemented a "nanokernel" that handled some underlying
aspects much better than the previous monolithic kernel. In addition to
stability increasing dramatically, MP really hooked in well with the OS.
File system operations became MP native, and so did some of the GUI.
Prior to this the second CPU could be brought in through additional
software, but with 8.6, support became native. With MacOS 8.0 and
8.5, the second CPU on my DP card went virtually unrecognized by the OS.
When I installed a beta version of 8.6 (I was a member of Apple's
developer program at the time), the performance increase was staggering.

> > For pure performance, though, I'll
> > take a single 300MHz G3 upgrade card over a DP 180MHz 604e card (and
> > I'm a big fan of MP because slower CPUs are cheaper than faster ones
> > and MP horsepower can be done cheap).
> I agree - for everyday work my 300MHz G3 with 1MB cache is way faster
> than the two 604es at 233MHz and only the slow mainboard cache. When
> it comes to FPU-bound tasks it's the other way around though.

The G3 was optimized for the MacOS, which doesn't require a lot of FPU.
It made the OS more responsive, but the 604 has much better FPU design,
which was extended on the next iteration of that design family, the G4
(with Altivec). It's like comparing four cylinder and eight cylinder
motors. Both can be tuned for massive horsepower, but when it comes to
towing a trailer up a mountain, there's only one choice.

tim