Installing Linux on an iMac

What Linux distro is the best for iMac? For a week, by searching with google, I found out that YellowDog is the best. I have to verify it myself by installing one. Before this, I have run Ubuntu Live CD PowerPC Edition to find out whether Linux can be installed on iMac. I couldn't believe my eyes. It was running perfectly. Now it's time to install to hard disk and wipe out the Mac OS 9.

My iMac is a G3 with 60 GB hard drive and Riva 128 is the graphic adapter.

SuSeLinux:~ # cat /proc/cpuinfo
processor : 0
cpu : 745/755
temperature : 27-29 C (uncalibrated)
clock : 400.000000MHz
revision : 50.2 (pvr 0008 3202)
bogomips : 49.79
timebase : 24967326
machine : PowerMac2,2
motherboard : PowerMac2,2 MacRISC2 MacRISC Power Macintosh
detected as : 66 (iMac FireWire)
pmac flags : 00000014
L2 cache : 512K unified
pmac-generation : NewWorld
SuSeLinux:~ #

SuSeLinux:~ # lspci
00:0b.0 Host bridge: Apple Computer Inc. UniNorth AGP
00:10.0 Display controller: ATI Technologies Inc Rage 128 PR/PRO AGP 4x TMDS
0001:10:0b.0 Host bridge: Apple Computer Inc. UniNorth PCI
0001:10:17.0 Class ff00: Apple Computer Inc. KeyLargo Mac I/O (rev 03)
0001:10:18.0 USB Controller: Apple Computer Inc. KeyLargo USB
0001:10:19.0 USB Controller: Apple Computer Inc. KeyLargo USB
0002:20:0b.0 Host bridge: Apple Computer Inc. UniNorth Internal PCI
0002:20:0e.0 FireWire (IEEE 1394): Apple Computer Inc. UniNorth FireWire (rev 01)
0002:20:0f.0 Ethernet controller: Apple Computer Inc. UniNorth GMAC (Sun GEM) (rev 01)
SuSeLinux:~ #

With Ubuntu, to my surprise, the installer couldn't enter X mode. I tweaked the xorg.conf to make it work. I failed. I got no time to tweak a little bit more. I turn to Yellow Dog. The Yellow Dog installer also failed to enter X mode. Lastly, I turned to OpenSuSe. To my relief, it worked. The gui installer had no difficulty to run. After booting, the X worked but the screen was not centered. I tweaked xorg.conf a little bit. It's easy with xvidtune than SaX2. Now the screen looked better. You didn't have to be a rocket scientist to tweak it. :p

The monitor section :

Section "Monitor"
DisplaySize 300 230
HorizSync 60-60
Identifier "Monitor[0]"
ModelName "APPLE IMAC"
Option "DPMS"
VendorName "APP"
VertRefresh 75-117
UseModes "Modes[0]"
EndSection

The modeline section :

Section "Modes"
Identifier "Modes[0]"
Modeline "1024x768" 78.525 1024 1049 1145 1312 768 769 772 800 +hsync +vsync
Modeline "1024x600" 89.40 1024 1088 1200 1376 600 601 604 637
Modeline "1024x600" 88.39 1024 1088 1200 1376 600 601 604 636
Modeline "1024x600" 87.51 1024 1088 1200 1376 600 601 604 636
Modeline "800x600" 69.65 800 848 936 1072 600 601 604 637
Modeline "800x600" 68.86 800 848 936 1072 600 601 604 636
Modeline "800x600" 68.18 800 848 936 1072 600 601 604 636
Modeline "768x576" 66.54 768 816 896 1024 576 577 580 613
Modeline "768x576" 65.80 768 816 896 1024 576 577 580 612
Modeline "768x576" 65.18 768 816 896 1024 576 577 580 612
Modeline "640x480" 50.03 640 680 744 848 480 481 484 513
Modeline "640x480" 49.59 640 680 744 848 480 481 484 513
Modeline "640x480" 49.16 640 680 744 848 480 481 484 513
EndSection

The device section :

Section "Device"
BoardName "Rage 128 PR"
BusID "0:16:0"
Driver "ati"
Identifier "Device[0]"
Screen 0
VendorName "ATI"
Option "AGPMode" "true"
# Option "UseCCEFor2D" "false"
# Option "UseFBDev" "true"
Option "ForcePCIMode" "true"
EndSection

Running Linux on iMac is a wonderful thing. Linux is Linux. Whatever platform it is running, you can turn it to be a server, workstation or desktop. You decide.

AMD Opteron vs Intel Itanium

Recently, I attended a seminar on Grid Computing and HPC. The organizer invited an Indian speaker, a sales director of SUN India, Mr Mohan. In his brilliant speech, many useful information gathered by me especially the decision made by SUN to opt for AMD Opteron on many its HPC products instead of Intel Itanium (in terms of commodity 64-bit CPU).

Why Opteron?
These are the reasons (briefly):

1. Allows end users to run their existing installed base of 32-bit applications and operating systems at peak performance, while providing a migration path that is 64-bit capable.

2. HyperTransport technology - provides a scalable bandwidth interconnect between processors, I/O subsystems, and other chipsets. This feature is not available in Itanium.

3. Integrated DDR DRAM Memory Controller - this memory is integrated in CPU itself. For Itanium, the memory is outside of CPU. According to Mr Mohan,Itanium introduced FSB (Front Side Bus) to connect CPU to external RAM. This increases latency.

4. Low-Power Processors - the AMD Opteron processor offers industry-leading performance per watt making it an ideal solution for rack-dense 1U servers or blades in datacenter environments as well as cooler, quieter workstation designs. This is a critical factor for HPC environment.

The bottomline is Opteron is more scalable than Itanium in terms of speed. If we add more CPUs, the Opteron speed will increase as opposed to Itanium. To make things worse, the bandwidth between CPUs will be divided evenly.

These are distinctive features on AMD Opteron that made it suitable for SUN to bundle it for their server products. Although Intel is popular, for technical people, popularity is nothing. The technical side of it is more important and pricewise it is cheaper too.

ps : This article is not endorsed by AMD :-)

64 bit is the way to go...

The server is up and running. It is a 64-bit Xeon with two processors.

[root@flowerhorn ~]# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2800.216
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi m
mx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl cid cx16 xtpr
bogomips : 5521.40
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:

processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2800.216
cache size : 1024 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi m
mx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl cid cx16 xtpr
bogomips : 5586.94
clflush size : 64
cache_alignment : 128
address sizes : 36 bits physical, 48 bits virtual
power management:
[root@flowerhorn ~]#

Sorry. the info was cut a little bit here and there. The point here is, it has 2 cpus (see processor 0 and 1 and it is Xeon 2.8 Ghz)

Here is the memory info :

[root@flowerhorn ~]# cat /proc/meminfo
MemTotal: 1024604 kB
MemFree: 11644 kB
Buffers: 36896 kB
Cached: 259168 kB
SwapCached: 76 kB
Active: 778852 kB
Inactive: 174596 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 1024604 kB
LowFree: 11644 kB
SwapTotal: 2618552 kB
SwapFree: 2614760 kB
Dirty: 448 kB
Writeback: 0 kB
Mapped: 689168 kB
Slab: 27868 kB
CommitLimit: 3130852 kB
Committed_AS: 1189824 kB
PageTables: 11904 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 269992 kB
VmallocChunk: 34359468047 kB
[root@flowerhorn ~]#

MemTotal = Total memory (it is 1 GB)

Older Xeon processor is 32-bit. The latest one is 64-bit. I heard that AMD's Opteron is superior in benchmark of 64-bit CPU. If I need one more server, I will opt for Opteron. To take advantage of 64-bit CPU, one should install 64-bit OS and applications if they are available. That's what I did. I did install Mandriva 64-bit and Slamd64.

[root@flowerhorn ~]# uname -a
Linux flowerhorn.censored.org 2.6.12-12mdksmp #1 SMP Fri Sep 9 17:20:34 CEST 2005 x86_64 Intel(R)
Xeon(TM) CPU 2.80GHz unknown GNU/Linux
[root@flowerhorn ~]#

Come on guys. Take advantage. That's the key point here. :)