Re: [PATCH 2/4] drm/i915: set min delay to rpe delay (Efficient frequency) for better performace.

S, Deepak
2013-12-09T13:58:31Z

Hi Chris,

My understanding is that running at efficient freq (RPe) where RPe is greater than the min freq (RPn) (RPe > RPn), at same Vmin voltage should give us better performance right?. Please correct me if my understand is not right

Thanks
Deepak

-----Original Message-----
From: Chris Wilson [mailto:chris@chris-wilson.co.uk]
Sent: Sunday, December 8, 2013 9:37 PM
To: S, Deepak
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 2/4] drm/i915: set min delay to rpe delay (Efficient frequency) for better performace.

On Sun, Dec 08, 2013 at 02:16:44PM +0530, deepak.s@intel.com wrote:
> From: Deepak S <deepak.s@intel.com>
>
> We use RPe here since it should match the Vmin we were shooting for.
> That should give us better perf than if we used the min freq available.
> System thermal can take the system to lowest possible freq (RP1). We
> are making sure, we calmp the freq to min_delay (RPe).

Your perf arguments are fallacious.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre