Author: Vincent Diepeveen
Date: 11:25:20 03/26/02
Go up one level in this thread
On March 26, 2002 at 13:50:02, Tom Kerrigan wrote: >On March 26, 2002 at 12:01:30, Vincent Diepeveen wrote: > >>If you manage to turn on SMT at the P4 chip, sure :) >>Intel has put on its homepage however that 'currently it is turned >>off at the chip'. >>hehehehehehe > >I don't see why you're laughing, because you pretty much just admitted that >you're an idiot. How can you go around declaring that HyperThreading is a load >of marketing crap that yields no performance gain when you have absolutely NO >data on the issue? You are the idiot here believing that Hyperthreading gives something when they admit that the current P4s 'currently have it turned off'. How can a feature work when it is 'turned off' in hardware, to use intels own words? Apart from that there is the theoretic discussion whether it would *ever* work for a P4. the answer is no in all respects. Too small L1 datacache and small L2 cache (with around 5 clocks penalty) >>that in DIEP i can do (multiprocessing) >>if( quickboard[sq_d3] == whitebishop ) >>where with multithreading you always need indirection: >>if( thisthread->quickboard[sq_d3] == whitebishop ) >>SEE WHAT I MEAN? > >This is a chess-specific issue, not an issue with threading in general, and it's >not even a performance problem depending on the addressing modes that your >processor supports. > >But it doesn't even matter, because the P4 exposes itself as two logical >processors, so you can just run two Diep processes on it. No need for threading. >You would have known this if you had paid attention to my previous posts. Now >you just look like an idiot. > >>>I can do math, but have you taken a computer organization class? It doesn't >>>matter how big your stupid data structures are, the only thing that matters is >>>how big your working set is. >>I'm not the fool here Tom, please see above. You forget an overhead >>which is pretty big and causes processors like the P4 to be not happy. > >You are the fool, because you can't follow a simple argument about working sets. >What does your indirection argument have to do with cache thrashing?? > >>>Really, how about you give us some measurements? Oh, right, you don't have any. >>>You make these numbers up. >>I'm at least measuring things where possible. You have had 1 theoretic >>class where probably teachers told you thread = process. Well it isn't. > >Well, if you're measuring things where possible, then you should have no problem >telling us EXACTLY how many instructions/clock Diep retires. So...? > >>In fact if you read in the API from M$ the first sentence then it will >>show you even more trouble when multithreading under windows. It says >>that when a thread is doing graphics, that all other threads are >>getting blocked when one of the threads is performing work. > >Then don't do graphics with your chess threads. > >-Tom
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.