Originally posted by Dr.Bimane
Here is my $0.02...
I use both macs and pcs and honestly find the "speed difference" negligible.
But here is the interesting thing. PCs are up to 2.5 GHz while Macs are now around 1 GHz. So when these SPEC benchmarks periocially come out, a PC should be 150% (2.5X) faster than a mac on the various tasks but this is NEVER the case. At most, the mac loses by 20% or even comes out faster, depending on if the test uses Altivec.
Thanks for pointing this out. The SPEC tests never use AltiVec, and as the NASA paper I quoted pointed out, that makes a big difference.
I read those test results where TechTV or whomever says, "Macs are crushed by PCs" but when you look at the results, it is a mere 20% margin at most. When your clock speed is 2.5X, I think that you should be ashamed to be only 20% faster. It is obvious that intel has found a way to scale up their MHz without really increasing real-world speed.
Intel gets its high clock speeds by having a much longer pipeline. So even though the CPU is running faster, it's doing less per clock cycle in comparison to the G4. And if it makes an error, it has to wait for the instruction to flush from the long pipline. The G4 is doing something like 4 times as many instructions per clock cycle, and since it is a RISC processor, the instructions are shorter words as well. A typical x86 instruction is as long as 4 PPC instructions.
Also the Floating Point unit on the P4 also doubles as the Vector unit, so even though it can do double precision vector processing, it has a latency time involved due to switching modes. The MPC 7450 has 4 Altivec units, each handling 128-bits, as well as a double precision FP unit.
But all this aside, will one be able to type a paper or report 3 times faster on a 3 GHz PC (when it becomes available) than on a 1 GHz PC? Oh, I bet you would be able to type up an e-mail and send it faster....give me a break.
Well it will Blue Screen a bit faster
😉
Most people don't need or even use all the speed anyway.
I agree! The big bottle neck was the memory bus, but the
Xinet benchmarks show the XServe out performing P4 servers. If these G4's are really using the MPC7470 (MacOS Rumors say they are not) then all the more better!
The PPC is a better CPU, but we
DO need much faster clock speeds.
