Another Simple Question - performance differences between bulk and interrupt

NTDEV
1

Hi there again!
Just one question: is there a practical performance difference between bulk and interrupt mode?

Thanks!

Lucas.

Fale com seus amigos de gra?a com o novo Yahoo! Messenger
http://br.messenger.yahoo.com/

2

Yes there is, but the answer depends on what kind of performance you are looking for, and what environment you are running in.

In the most common case, bulk endpoints will have superior throughput over interrupt endpoints. Only on very congested systems would interrupt do better.

If the endpoint is an IN (from the device to the host) and going to only send data very rarely, then the interrupt endpoint will result in “wasting” less overall usb bandwidth than if that same data were sent over bulk. This is assuming you have to constanstly poll the endpoint because you don’t know when the data will be available.

From: xxxxx@lists.osr.com on behalf of Lucas Bracher
Sent: Sat 12/16/2006 8:19 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Another Simple Question - performance differences between bulk and interrupt

Hi there again!
Just one question: is there a practical performance difference between bulk and interrupt mode?

Thanks!

Lucas.

Fale com seus amigos de gra?a com o novo Yahoo! Messenger
http://br.messenger.yahoo.com/

Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer