DaemonForums  

Go Back   DaemonForums > Miscellaneous > General Hardware

General Hardware General hardware related questions.

Reply
 
Thread Tools Display Modes
  #1   (View Single Post)  
Old 26th July 2011
Ninguem Ninguem is offline
Shell Scout
 
Join Date: Jun 2011
Posts: 136
Thanked 0 Times in 0 Posts
Default Differences in processing in POWER CPUs.

I've noticed recently that building KDE4 on an iMac G4 with an 800MHz processor seems to be more efficient than when I built the same on a PowerMac G4 with a 933MHz processor. I'm curious as to whether it was an issue with the Quicksilver or if the iMac was built better.
Both processors are Altivec, load-store and fpu active with one being a 7450 and the other a 7455- if that makes any difference.
Reply With Quote
  #2   (View Single Post)  
Old 27th July 2011
Carpetsmoker's Avatar
Carpetsmoker Carpetsmoker is offline
Real Name: Martin
Old man from scene 24
 
Join Date: Apr 2008
Location: Eindhoven, Netherlands
Posts: 2,062
Thanked 198 Times in 156 Posts
Default

I'm from the x86 generation, so I'm not an expert, but aren't these machine PowerPC, and not POWER?

In any case, clockspeed is only one (small) metric of the overal speed of a CPU. See: http://en.wikipedia.org/wiki/Megahertz_myth
__________________
UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things.
Reply With Quote
  #3   (View Single Post)  
Old 27th July 2011
Oko's Avatar
Oko Oko is offline
Fsck Surgeon
 
Join Date: May 2008
Location: Kosovo, Serbia
Posts: 759
Thanked 36 Times in 32 Posts
Default

Quote:
Originally Posted by Ninguem View Post
I've noticed recently that building KDE4 on an iMac G4 with an 800MHz processor seems to be more efficient than when I built the same on a PowerMac G4 with a 933MHz processor. I'm curious as to whether it was an issue with the Quicksilver or if the iMac was built better.
Both processors are Altivec, load-store and fpu active with one being a 7450 and the other a 7455- if that makes any difference.
How much RAM memory do you have on each machine? What is the buss speed?
How much cash memory each processor have? Anything could be the reason. If I am not mistaken both machines are PowerPC? Right?
Reply With Quote
  #4   (View Single Post)  
Old 27th July 2011
rocket357's Avatar
rocket357 rocket357 is offline
Real Name: Jonathon
Wannabe OpenBSD porter
 
Join Date: Jun 2010
Location: 127.0.0.1
Posts: 317
Thanked 9 Times in 9 Posts
Default

More plays into it than CPU speed...does the 800 MHz machine have more RAM? Faster disks? Different compilation settings? Different compiler versions? Different compilers? Different OS's?
__________________
Linux Admin by Profession. OpenBSD user by choice.
Reply With Quote
  #5   (View Single Post)  
Old 27th July 2011
Ninguem Ninguem is offline
Shell Scout
 
Join Date: Jun 2011
Posts: 136
Thanked 0 Times in 0 Posts
Default

http://www.everymac.com/systems/appl...g4_933_qs.html

Lists:
Quote:
System Bus Speed: 133 MHz Cache Bus Speed: 933 MHz* (Built-in)
Details: This system has a 256k "on chip" level 2 cache running at processor speed (933 MHz) and a 2 MB DDR SDRAM backside level 3 cache "with 3.7-GBps throughput"..
http://www.everymac.com/systems/appl...ac_800_fp.html

Lists:
Quote:
System Bus Speed: 100 MHz (8:1) Cache Bus Speed: 800 MHz (Built-in)
Details: N/A
The Quicksilver PowerMac G4 has 1.5G RAM, FreeBSD 9.0 and the iMac has 786M RAM also with FreeBSD 9.0.


A problem I have with the Quicksilver is one of the disks had trouble running/being recognized. There would be a click-whirling sound while the disk was being accessed. I removed it and placed it into a B&W. The same disk worked fine in the other machine.

rocket357, I'm not sure about the disk speed on either model. Checking ad0 for the iMac gives me Seagate ST360015A- .

I don't have the Quicksilver up right now; but, I can get those specs up later.

Last edited by Ninguem; 27th July 2011 at 08:21 PM.
Reply With Quote
  #6   (View Single Post)  
Old 25th August 2011
Ninguem Ninguem is offline
Shell Scout
 
Join Date: Jun 2011
Posts: 136
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by http://www.osnews.com/story/3997/Analysis_x86_Vs_PPC/page3/
The idea that x86 have RISC-like cores is a myth. They use the same techniques but the cores of x86 CPUs require a great deal more hardware to deal with the complexities of the original instruction set and architecture.
I've wondered about this for reason that compiling and performance is nearly the same for processors within each architecture.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Super-secret' debugger discovered in AMD CPUs J65nko News 3 16th November 2010 12:58 AM
Processing 1.0, the open source programming language and environment and others. tetrodozombie OpenBSD General 7 18th December 2009 02:40 PM
portability to allegedly byte compatable but non-i386 CPUs jimbus FreeBSD Installation and Upgrading 2 23rd September 2008 04:03 AM
Post Processing themaster FreeBSD General 0 12th June 2008 08:26 PM
Alternative Word Processing and Spreadsheet Applications enpey FreeBSD Ports and Packages 13 7th June 2008 09:27 AM


All times are GMT. The time now is 02:52 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content copyright © 2007-2010, the authors
Daemon image copyright ©1988, Marshall Kirk McKusick