From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephane Eranian Date: Fri, 24 Oct 2003 17:10:44 +0000 Subject: Re: Itanium2@900MHz slower than alpha@666MHz ? Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Ionut, On Fri, Oct 24, 2003 at 06:26:55PM +0200, Ionut Georgescu wrote: > Yes, it is a 1.5MB cache CPU. > > But it might be more than just cache misses. When running with a 256x256 > grid, I am actually using 3 256x257 matrices, which is slightly over > 1.5MB. I just made a comparison with a 32x32 grid and the difference is > the same: alpha 10.294s, zx2000 14.777s . -O3 is only by 0.4s faster > than -O2 in this case. > Another thing to check is the syslog. Check to see if your program is not getting "floating point software assist" fault. That can slow you down significantly. -- -Stephane