Go Back   Hardware Canucks > HARDWARE CANUCKS COMMUNITY > HardwareCanucks F@H Team

    
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old October 13, 2011, 03:05 PM
geokilla's Avatar
Hall Of Fame
F@H
 
Join Date: Aug 2008
Location: Toronto
Posts: 3,615

My System Specs

Default SMP Folding @ 50% to 75% = 0 Progress?!

I have my SMP client folding at 50% to 75% because lately, me botting in RuneScape requires 25% to 50% CPU overhead. However with the A3 core chugging along at 50% to 75% CPU usage, my TPF is over 2 hours. What the hell?! Is there a way to fix this? How can a 25% to 50% drop in CPU resources result in such a huge drop in TPF? Even my old Athlon X2 can fold better than this.
__________________
Reply With Quote
  #2 (permalink)  
Old October 13, 2011, 03:38 PM
Dead Things's Avatar
Hall Of Fame
F@H
 
Join Date: Oct 2008
Location: Centre of the Universe
Posts: 1,560

My System Specs

Default

Sounds like an affinity problem. That is, thread imbalance such that the core is spending a big chunk of its CPU cycles waiting.

Think of it like this:

00:00 Thread 1 starts job 1a
00:00 Thread 2 starts job 2a
00:30 Thread 1 finishes job 1a
00:45 Thread 2 finishes job 2a
00:45 Thread 1 starts job 1b
00:45 Thread 2 starts job 2b

Since thread 1 can't start job 1b until it gets the job 2a information from thread 2, then its CPU time between 00:30 and 00:45 is just cycling in wait, not really doing anything. The more threads you have, the more they will have to wait if their cycles fall out of symmetry, and when this happens to a symmetrical task with linear progression such as fah, it could cause all kinds of problems.

So to reduce CPU usage, you would probably be better served by doing all of the following:

a) Leaving usage at 100% in the client config
b) Using the smp flag to reduce the number of processing threads available to fahcore
c) Using a program like WinAFC to assign and limit the fahcore to specific threads

That way, the process will maintain better symmetry and waste fewer CPU cycles waiting.
__________________
Follow my folding, mining & benching shenanigans @dt_oc!
Proud to be Folding @ Home
deadthings @ Team 37412



Think you can overclock? Then show us what you got!
Join the Hardware Canucks Overclocking team today!
Reply With Quote
  #3 (permalink)  
Old October 13, 2011, 05:14 PM
geokilla's Avatar
Hall Of Fame
F@H
 
Join Date: Aug 2008
Location: Toronto
Posts: 3,615

My System Specs

Default

Reducing the number of cores by using -smp 3 flag doesn't help. Been one hour now and still 0 progress. Also doesn't explain why my sister's Phenom II can manage to have a TPF of around 15 minutes while she plays her Facebook games or MapleStory. Those games use at the very least 25% of CPU overhead, just like my bots in RuneScape.
__________________

Last edited by geokilla; October 13, 2011 at 05:29 PM.
Reply With Quote
  #4 (permalink)  
Old October 13, 2011, 05:44 PM
chrisk's Avatar
Folding Captain
 
Join Date: Jul 2008
Location: GTA, Ontario
Posts: 7,396

My System Specs

Default

Try deleting the WU and queue files.
__________________
Fold for team #54196
Reply With Quote
  #5 (permalink)  
Old October 13, 2011, 07:56 PM
geokilla's Avatar
Hall Of Fame
F@H
 
Join Date: Aug 2008
Location: Toronto
Posts: 3,615

My System Specs

Default

Quote:
Originally Posted by chrisk View Post
Try deleting the WU and queue files.
I think it might've been because I had -smp 2 and -smp flags, which meant the -smp flag had more priority to use as many cores as possible. Going to give it another try.

Still doesn't explain why I can still fold normally with a linear drop in PPD when I run flash in 720P or why my sister can still put out TPF of about 15 minutes when she plays her games....
__________________

Last edited by geokilla; October 13, 2011 at 08:03 PM.
Reply With Quote
  #6 (permalink)  
Old October 13, 2011, 08:20 PM
Dead Things's Avatar
Hall Of Fame
F@H
 
Join Date: Oct 2008
Location: Centre of the Universe
Posts: 1,560

My System Specs

Default

Quote:
Originally Posted by geokilla View Post
Still doesn't explain why I can still fold normally with a linear drop in PPD when I run flash in 720P or why my sister can still put out TPF of about 15 minutes when she plays her games....
No it doesn't. Which is why Chris might be right about the WU being borked. Do you see any mention of the WU you're working on in here?
__________________
Follow my folding, mining & benching shenanigans @dt_oc!
Proud to be Folding @ Home
deadthings @ Team 37412



Think you can overclock? Then show us what you got!
Join the Hardware Canucks Overclocking team today!
Reply With Quote
Reply


Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
How to set up HFM.NET and FahMon to monitor Folding@home progress. Now with videos. chrisk HardwareCanucks F@H Team 132 November 2, 2012 06:07 PM
K6 Desk Mod (in progress) Keep-six Case Mods, Worklog & Gallery 0 September 8, 2011 09:20 PM
i7 Build in progress Jelah New Builds 15 August 29, 2010 04:15 PM
Progress report E6400 bushwickbill Overclocking, Tweaking and Benchmarking 5 October 12, 2007 07:19 PM
No progress Amon HardwareCanucks F@H Team 21 August 30, 2007 06:43 AM