From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH] drm/i915: initialize ring frequency scaling table on SNB Date: Wed, 22 Jun 2011 12:30:17 +0100 Message-ID: References: <20110621152424.75f54a13@jbarnes-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 2E7A29E7BC for ; Wed, 22 Jun 2011 04:30:22 -0700 (PDT) In-Reply-To: <20110621152424.75f54a13@jbarnes-desktop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Jesse Barnes , intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Tue, 21 Jun 2011 15:24:24 -0700, Jesse Barnes wrote: > The ring frequency scaling table tells the PCU to treat certain GPU > frequencies as if they were a given CPU frequency for purposes of > scaling the ring frequency. Normally the PCU will scale the ring > frequency based on the CPU P-state, but with the table present, it will > also take the GPU frequency into account. The scaling_factor used in > this patch may not be ideal, but is enough to increase performance in > nexuiz on a 1366x768 panel by about 20%. Am I right in thinking that the improvement offered by these new defaults is dependent upon the previous values programmed by the BIOS? On my desktop SNB, I only see a marginal improvement (<~1%) for games and similarly small differences for cairo-gl/xlib. Plus they also revealed my confusion over dev_priv->min_delay is actually min_freq on SNB. Evil. :-p -Chris -- Chris Wilson, Intel Open Source Technology Centre