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Benjamin Herrenschmidt On PPC/Linux, Apple and OSS
MacBoy writes "The folks over at ResExcellence have a great interview with Benjamin Herrenschmidt, kernel guru for the PPC/Linux camp. He offers up some history of Linux on Apple and PPC hardware, and some discussion on Apple's current and past contributions to the open-source and Linux communities. He makes some interesting comparisons of Linux on PPC vs. Intel hardware, such as the ease of getting important patches into the kernel on PPC compared to Intel. It's an interesting read, especially if you are amoung the many who covet the new Dual-CPU GHz G4 Macs and want to know a little more about the PPC/Linux community."
PPC/Linux seems like an ambitious and technically interesting project, no doubt. Personally, though, I don't seem to understand the purpose. MacOs X is based on BSD, so you get all the nice Unix-like server features... and a decent GUI, something that Linux has never had. Are there some other advantages of Linux/PPC that I'm missing?
If guns kill people, then CmdrTaco's keyboard misspells words.
I was going to ask if anyone has Linux running on the new dual G4's, but then I found this cool link
http://linuxppc.org/hardware/dualg4/
Anyone have benchmarks (under Linux) for the dual G4's and corresponding PCs for:
- compiling the kernal
- GIMP
- Quake1/2 benchmarks
I'd love to get the "other endian machine" and compile some game code on it. Anyone have any recommendations? How did id do the Quake3 port to Macs ?
"PC Expert - Mac newbie"
The lmbench numbers show that linux is significantly faster for certain operations. I have a copy of the results that I pointed to in an old post over here. Linux spanks OS X. It's a reason.
Other reasons include access to all of the source of your OS and better support for certain things (pcmcia 802.11b card support? Better filesystems. More software already working).
I personally run Debian on my laptop 99% of the time because my environment is the same everywhere, and apt-get kicks ass (fink on OS X is cool, but there isn't as much stuff available).
When (and only when) each instruction takes one clock cycle to execute you can divide each instruction inte several sub-tasks, for example Fetch - Decode - Execute - Store. Now a pipeline can be introduced:
instruction 1 F D E S
instruction 2 . F D E S
instruction 3 . . F D E S
instruction 4 . . . F D E S
In this way work is parallellised. Four instructions are executed in parallell, during 4 clock cycles each, giving a throughput of 1 instruction per second.
CISC basically means that instructions take different number of clockcycles to execute. With such an instruction set you can not use Pipelining.
The i386 cpus today transform the CISC instructions into RISC instructions, and apply pipelining. For the price of a translator the major drawbacks with CISC are avoided.
It is probably true that Intel has to put more research and silicon into a CPU than Motorola to achieve the same performance. But this is not because Intel are stuck with building a CISC cpu - it is because Intel must emulate the i386 CISC instruction set on a RISC cpu core.
Linux is often faster. Just like Intel Linux, it's possible to create a custom stripped down desktop with no fat. I've become accustomed to how things work on my Intel Linux machines and like having almost the same environment on my Pismo Powerbook. I also prefer the GNU utilities over the BSD ones (flame away...it's just a preference...get over it).
OSX is also next to useless on older hardware. We use 233Mhz Beige G3 desktop as an internal server. It's running ssh, Apache-SSL, NTP, mySQL, Apache, and Netatalk. The Apache/mySQL setup powers our troubleticket/inventory system. The Netatalk/Samba combo makes files available to both Mac and Windows clients. It does all of this with very acceptable speed and reliablity. The machine has zero need for a GUI...and doesn't have one. I suppose I could use Darwin but the machine wouldn't do it's work any better and I would have to mess with fussy ports of the daemons. It has full apt-get goodness....I forgot to mention that it is dead easy to admin.
So yeah, there are valid reasons to use Linux on PPC hardware.