Is there a way to tell how many processors software can utilize?

[NYImola::NYMisano]

Ie: would certain stock trading software apps use any more than a dual core?

[pattycakes® iCode]

Generally you will only be able to tell that is if it does something to put all your cores under 100% load (lots and LOTS of high priority number crunching).

Otherwise Windows will schedule the threads to the first free processor so you'd never really be able to tell.

[allroadCole]

download and run Process Explorer

fire up the app in question

find the app in question in Process Explorer and double click it

click on the "threads" tab, and look at how many threads are using the CPU at a time.

[pattycakes® iCode]

99.999999% of the worlds applications are multi-threaded (as are their linked dependencies).

Just not many of them are actually optimized to actually run on multiple core / CPU systems though.

[pattycakes® iCode]

You want to know how many it can make use of?


Short answer is; However many your system has.

Really the only applications that tend to increase / decrease the number of worker threads based on the number of CPUs / Cores

-and-

Manages / loads those threads properly are;

Video games, video, photo and audio editing suites.

Otherwise, your OS will manage thread scheduling for your stock application across all CPUs / Cores based on a thread scheduling engine.

Those types of applications tend to be weighted towards one thread lording over all the rest, but you'll see these threads scheduled across all available CPUs / Cores in certain conditions.

[allroadCole]

of course all applications will have several threads. but the process explorer shows you what CPU % each thread is using. In most apps when you do something processor intensive only one thread will be using the CPU and the rest of the threads will be idling.

so, if you press the "start cpu intensive task" button in the application in question and only one thread starts using a non-trivial amount of cpu, then that intensive task will not directly benifit from multiple cores (right?). but if you press the "start cpu intensive task" button and 2,4, 8 or more threads start using a decent amount of CPU you will get a huge benifit from multiple cores...

of course im assuming each thread runs on only one processor, which im pretty sure used to be true, but maybe newer versions of windows let one thread span multiple cpus/cores????

[pattycakes® iCode]

But using procexplorer is kind of overkill in this situation IMO;

Yes, you're going to get a granular view of thread scheduling for the entire life cycle of the application. But seeing one spawned thread spike utilization for a clock cycle on another core isn't uncommon given the math behind that number and what spawned threads do from time to time.

And you're also right that it's the ability to sustain that CPU usage figure across the lifespan of the application that's the key to determining if that app has a threading model designed to take advantage of multiple cores.

But you can see that in Task Manager.

In your scenarios;

The first one you will see a marginal increase in perf, only because the application will suffer less thread context switching through its lifespan. All those threads that used to share time on a single core machine can be farmed out to other cores.

The second scenario is what you see more of today, apps that are multithreaded but weighted towards a single thread, this model tends to give you a 10-20% perf increase and generally leaves you seeing a 100%-50% usage split on a dual core machine in Task Manager (given it's something that really runs around crunching numbers...i.e. games).

And threads can't be split across CPUs as yet. True parallel thread computing isn't quite there yet. It requires pretty hefty CPU and software architecture changes.

[amidcars]

I used to use a online software for trading and usually use it for day trading. I am using it on a celeron processor lapi. I dont find any problem even in the laptop processing slow or other issues. Its running good in ti and if you have dual core then there would not be any type of problem..