Bryan J. Smith <b.j.smith@ieee.org>
2005-Jul-01 00:33 UTC
[CentOS] Re: Hot swap CPU -- "build" is not a good CPU benchmark
From: Peter Arremann <loony at loonybin.org>> It is a valid benchmark though :-) compile speed is a actually a > good measure for any integer app that is small enough to run in > large cache... Image processing, oil companies for their simulations, > cad... they all act very similar to compile benchmark - if a compile > is twice as fast, a software image rendering is usually twice as fast > too :-)Now hold on. Did I just here you state that the ALU is used for CAD, and most scientific and engineering applications? Now I'll grant you that _some_ image processing _can_ be 32/64-bit integer transforms. But most high-quality, 64-bit precise transforms use the FPU. Not even Intel's SSE (on the P3/P4) is good when you need such precision. In fact, I don't know how many times I've caught errors because someone threw the "-O3" switch on "-march=p4". You do _not_ want to use SSE for scientific computing -- it's for when you want performance in exchange for loss of precision (let alone accuracy).> If you run databases or so, then yes, your comment is valid.Thank you.> Fair enough :-)And people say *I* go off on tangents. No offense, you were already in 2 posts before I even responded. If you look at other threads, I'm typically responding "OT" after 2-3 people have done so, and I largely see an inaccuracy, or I see a correction very much necessary. [ My posts on that thread _prior_ had just been to inform people that yes, there _were_ Xeon and Itanium systems with hot-swap capability. ] That's all I was trying to do in this case. Not "prove you wrong." -- Bryan J. Smith mailto:b.j.smith at ieee.org