[Ti] like hell freezing over ?

[Chris Olson]

On Jun 5, 2005, at 12:20 PM, Henry Kalir wrote:

> Your address is one of computer engineering...so - enlighten us - can 
> I disconnect the liquid cooling system in the G5?

I'm not Kynan, and I don't play him on TV, but no you can't.  The chip 
would fail.  But the liquid cooling system could be easily replaced 
with air cooling.

> And - why is "everything is so dense"?? Is that a design flaw?

No, it's a design feature.  The PowerPC 970 is a much smaller chip than 
the P4, therefore you have a smaller surface area with which to remove 
heat by convection.  The smaller G5 chip only takes a fraction of the 
power it takes to run the Pentium

> And if it isn't - it's still generating a lot of heat for it's design, 
> right?

No, the PowerPC 970 is one of the most thermally efficient chips in 
existence.  Using the MS_hot benchmark on a G5, which executes 
exclusively out of the L1 cache, performing a tight loop of square root 
instructions, the power utilization of the G5 970 1.8 GHz (130 nm) is 
51 watts, and the G5 970 2.0 GHz is 66 watts. No conclusive data has 
been published by IBM for the 2.5/2.7.

I invite you to compare that to the power dissipation of the Pentium 4 
family, with many of them running at 100+ watts.

Liquid cooling is about getting rid of the heatsinks and placing the 
heat exchanger in a more ideal location for even cooling and airflow 
thru the rest of the machine.  The rest of the components in a G5 
create far more heat than the cpu(s) themselves - namely the PS, FSB, 
RAM, SATA disk(s), etc..

FWIW, you can't stuff a P-IV in a PowerBook either, any more than you 
can stuff one in a Mac mini.  In fact, one forlorn PC user tried to 
stuff a small form-factor PC motherboard/cpu into a Mac mini case when 
the mini first came out, and didn't have room to re-install the optical 
drive when he got it hacked in there.

It's all about engineering.  PC's are assembled from loose parts.  Mac 
aren't.
--
Chris