Not logged in
Log in now
Create an account
Subscribe to LWN
LWN.net Weekly Edition for May 23, 2013
An "enum" for Python 3
An unexpected perf feature
LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
Constant UI responsiveness
Posted Feb 27, 2009 12:02 UTC (Fri) by k3ninho (subscriber, #50375)
Posted Feb 27, 2009 13:18 UTC (Fri) by nlucas (subscriber, #33793)
MMX instructions appeared on the Pentium Pro (don't remember the model) and on Pentiums at 166MHz (there was two versions, one without MMX). And MMX has that problem of sharing the floating point registers.
Posted Feb 27, 2009 16:21 UTC (Fri) by vonbrand (subscriber, #4458)
The MMX and SSE stuff is about doing the same operation on several data in parallel (but working on small inputs, i.e., integers 8 bits wide). Some RISCy architectures have their own set of "multimedia" instructions.
Posted Feb 28, 2009 9:29 UTC (Sat) by nlucas (subscriber, #33793)
By the nature of the RISC architecture, a lot of simple vector operations coded by hand would always outperform the same thing on earlier x86 CPUs, like the first Pentium.
I suppose there are more complex multimedia cases where it makes sense to have dedicated instructions equivalent to SSE on RISC machines.
Posted Feb 27, 2009 17:08 UTC (Fri) by drag (subscriber, #31333)
Try making that old Risc machine drive a modern LCD display with Alpha blending and see how far you get.
Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds