On Sat, 28 Dec 2002 Jimen Ching wrote: | Date: Fri, 27 Dec 2002 22:59:48 -1000 (HST) | From: Jimen Ching <[EMAIL PROTECTED]> | To: [EMAIL PROTECTED] | | [snip]... | I heard the opposite. I heard the higher clock rates of the Pentium | 4's give you no advantages. I heard clock rates of 800Mhz is all you | need for home use and most business use. I also heard that an 800Mhz | PowerPC outperforms an 800Mhz Pentium II/III, and consumes less power. | Of course, performance benchmarks these days are heavily dependent on | other things besides CPU clock rates, like cache size/speed, and other | processor theories not related to the master clock.
Disclaimer: architecture is not my main area. But I have a PhD in computer science and taught a 400-level undergraduate computer architecture course just last spring, so I have at least one leg to stand on here... What you "need" for home and business use depends one what you do obviously. In your email you said you were going to do multimedia/ development (i.e. builds/compiles, run codecs, etc.); this sort of use would definitely benefit from higher clock speeds. The higher clock speeds of the Pentium and Athlon processors definitely give you an advantage over the *much lower* clock speeds of the G4. The G4 currently tops out around 1GHz (I believe). You are correct in assuming that the superior RISC design (with a smaller pipeline, but more issue/execute units) of the PPC will give you better performance than a P4 or Athlon *that are in the same ballpark*. i.e. a 1GHz PPC would probably outperform a 1.3GHz P4 and maybe even a 1.5GHz P4. This is same reason that a 1.6 GHz Athlon was outperforming a 2.0GHz P4. BUT P4's are currently topping out above 3GHz!! You have to build a dual processor PPC system just to be in the ballpark. Yes, cache, FSB, presence of L3 cache, etc. do make a difference, but for compute intensive code running out of the L1/L2 cache (codec loops, compiler optomization passes, etc.) having a higher clock will definitely help you out--the PPC (even though it is retiring more instructions/clock) is just not able to keep up. I saw a recent review (sorry don't remember where) of a dual 1GHz PPC against a 3GHz P4 with hyperthreading; the Mac lost on every benchmark. If you are doing I/O bound work rather than CPU bound work then, yes, you should save your money and buy a slower processor because it will be waiting most of the time anyway... | | >Don't get me wrong: I love my iBook running Yellow Dog Linux; but for | >browsing the web, email and similarly non-compute intensive tasks (I do | >curse the CPU at times :-) | | Isn't the iBook still using G3 processors? I believe these processors max | out at 600-700Mhz. But most of the G3 systems I've found doesn't come | anywhere close. What is your processor speed? Yes the iBooks are G3s. The clock speed on mine is 500MHz, I believe. Yes, the G3 to a G4 is like a P3 to a P4. Yes, G3's don't have Altivec acceleration or Velocity architecture of the G4. On a laptop, a high processor speed will eat into your battery life. I was not planning on doing anything "heavy" on the laptop, so it works out to save me a lot of juice. | >IMO, if you want to run Linux on a desktop or a server x86 is the clear | >way to go at the present time. | | I think this used to be the case. But after doing some research, I | found out a few things. First, Apple's hardware seems to be really | under powered. If you do a search for the Macs that came out between | 2000 and 2001, they are all G3 based, and under 500Mhz. There doesn't | seem to be any good reason for this. Second, I found lots of | information on upgrading your PowerMacs. Clearly, Apple's customers | also think the hardware coming out of Apple is under powered. I don't agree with this. They are tracking the top of the PPC manufacturing pretty closely. Witness: the dual 1GHz G4 is their current top of the line (they have been beating Motorola's door down trying to get them to build a faster chip, but Motorola does not have the market/fab/capitalization/design/?? to ramp the architecture up as fast as Intel and AMD). Even AMD is conceding the 32-bit performance crown to Intel, because nothing AMD has now in the 32 bit line is touching the P4's performance. | At this point, the only advantage that x86 have over PowerPC is the | software. There are clearly more software available for x86 than | Macs. But for Linux, this advantage disappears. Of course, Linux on | PowerPC is not as mature as Linux on x86. But for the parts that I | care about, it's close enough. ;-) Well, I have noticed the advantage even running Linux. If you are going to compile everything yourself, this may not be an issue. But it's much harder to find PPC RPMs than x86 RPMs. Also, some codecs that I've got running on my Athlon are not working on PPC because they use MMX/SSE/SSE2 optomizations. Some are available for PPC but use generic C code and so are not nearly as optomized. I notice this e.g. trying to build Xine or Ogle or VLC for PPC. As someone else, pointed out, the distros are running about 1 or 2 revs back on PPC vs. x86. For example, Yellow Dog Linux 2.3 (their latest) is based on Redhat 7.2, I think. They do backport a lot of stuff, including newer kernels, etc. but the whole distro "feels" old compared to, say, Redhat 8.0. One last thing: you mentioned that Firewire was competitive to SCSI (in your quoted email). Not to my understanding or experience. Firewire tops out at 400 Mbps or 50 MBps. Even IDE has a better transfer rate than this. Firewire is nice in that it is hot-plug; you can also do RAID tricks over firewire to increase the performance, but a good high-speed SCSI subsystem (or even IDE) will be much superior in terms of performance. Of course if you want a PPC because it is a "beautiful" architecture I totally understand. I preferred the beautiful 680x0 architecture back when it was competing with the "ugly" x86. But I'm just trying to help you out on the basis of performance/flexibility/price. --Eric -- Eric Jeschke http://cs.uhh.hawaii.edu/~jeschke