From owner-freebsd-hackers Sun Aug 3 02:25:09 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id CAA15928 for hackers-outgoing; Sun, 3 Aug 1997 02:25:09 -0700 (PDT) Received: from bugs.us.dell.com (bugs.us.dell.com [143.166.169.147]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id CAA15918 for ; Sun, 3 Aug 1997 02:25:05 -0700 (PDT) Received: from ant.us.dell.com (ant.us.dell.com [198.64.66.34]) by bugs.us.dell.com (8.6.12/8.6.12) with SMTP id EAA02549; Sun, 3 Aug 1997 04:22:00 -0500 Message-Id: <3.0.2.32.19970803041915.006a69e4@bugs.us.dell.com> X-Sender: tony@bugs.us.dell.com X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.2 (32) Date: Sun, 03 Aug 1997 04:19:15 -0500 To: Curt Sampson From: Tony Overfield Subject: Re: Pentium II? Cc: FreeBSD Mailing List , Tom Samplonius , hackers@FreeBSD.ORG In-Reply-To: References: <3.0.2.32.19970802024954.006dfb1c@bugs.us.dell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk At 03:10 PM 8/2/97 -0700, Curt Sampson wrote: > >On Sat, 2 Aug 1997, Tony Overfield wrote: > >> Since the hit rate of the L1 cache is usually much higher than that of the L2 >> cache, the effect of the slower L2 cache in the Pentium II is usually offset >> by the beneficial effect of not having to access it. So even at the same >> clock rate, the Pentium II can run faster than the Pentium Pro. > >Do you have any benchmarks that indicate this? I think many of the benchmarks indicate this. The benchmarks show, when run at the same clock frequency, that the Pentium II runs at speeds comparable to the Pentium Pro, even though the L2 cache is running at half-speed. Many folks had claimed that the Pentium II would be much slower because of the half-speed L2 cache. It should be easy to agree that larger L1 caches have higher hit rates. In turn, higher L1 cache hit rates reduce the demand on the L2 cache. Whenever the Pentium II is hitting in the L1 cache strictly due to its larger size, it will be faster. Whenever the Pentium II misses the L1 cache, it will be slower. >Or are you just dreaming? I sure hope not. I wouldn't want to waste a dream on this stuff. :-) - Tony