On Friday 05 March 2004 08:06 am, Gerhard den Hollander wrote:
* Bruce Marshall
(Fri, Mar 05, 2004 at 07:57:37AM -0500) I would more than likely go with a 64bit chip before I went to two processors. The inter-processor protocols, the physical parameters introduced by the finite propagation speed of electromagnetic impulses, and the need for software to support (external) SMP make it unattractive.
I have a P4 2.8 running quite nicely here with HT. Can we gin up some simple test to see what it does?
I think I have an answer for you and Lee is right.
I wrote a simple looping program that would show the elapsed time for nnnn passes through the loop. Run by itself, a valid time would be 1.55 secs for one pass. Start up another copy of the same program, and the time for each became 2.9. Close enough to twice the time that it's obvious the HT is a sham.
``obvious that HT is a sham'' and that is based on one simple looping program.
It's good enough for me...
Please read up onw hat HT is, what it does and under which circumstances it can be benificial.
I think I know what it is doing...
Or give it a try on your machien, and check the performance of a bunch of common programs with and witout HT.
It *IS* on my machine.
Your mileage may indeed vary, but I've found that enabling HT indeed gives a slightly snappier experience, and certain programs (esp once that do a lot of floating point operations and that are multithread aware) will clearly benefit from having it on.
But given that HT these dayts comes for free (more or less) it's a cheap test to turn it on .
I can agree with all of your points.... see my later message. I've been dealing with multi-engine machines (mostly large IBM mainframes) for the past 43 years so I think I know a little about schedulers (I've written a few) and cpu usage and what works and what doesn't. HT can have some advantages.... just not as much as a dual-cpu setup. And since I am subscribed to the list, please don't copy me on your posts. -- +----------------------------------------------------------------------------+ + Bruce S. Marshall bmarsh@bmarsh.com Bellaire, MI 03/05/04 08:15 + +----------------------------------------------------------------------------+ "Money will say more in one moment than the most eloquent lover can in years."