From tlumley at u.washington.edu  Fri Feb 20 13:10:24 2009
From: tlumley at u.washington.edu (Thomas Lumley)
Date: Fri, 20 Feb 2009 04:10:24 -0800 (PST)
Subject: [Rd] cpu bound cases
In-Reply-To: <049C4E48B10A854FB9D3B3C9DFAB506B011D5A1A@smarexmb1.amd.com>
Message-ID: <Pine.LNX.4.43.0902200410240.19096@hymn12.u.washington.edu>

On Thu, 19 Feb 2009, Rubin, Norman wrote:

> I'm considering some things AMD could do to accelerate R using GPU
> processors. In an internal discussion I was asked
>
> "Are there interesting R computations which are currently cpu bound?"
> I'm sure there are lots but I'd like to be able to name some real world
> cases.
>

It depends a bit on what you mean by cpu-bound.  Some of the arithmetic and mathematical functions are fairly clearly cpu bound, since Luke Tierney's multithreaded math library speeds them up.

The matrix operations in regression can easily push the CPU usage to 100%, but the success of ATLAS suggests that they may really be limited more by cpu memory bandwidth. I don't know if this counts.

Other people may have different suggestions.

        -thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle



[Rd] cpu bound cases
Thomas Lumley