From ripley at stats.ox.ac.uk  Sat Dec  4 20:47:55 2004
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Sat Dec  4 20:47:59 2004
Subject: [Rd] Re: [R] Running R from CD?
In-Reply-To: <Pine.LNX.4.61.0411251032450.25900@gannet.stats>
References: <20041122004120.67125.qmail@web50306.mail.yahoo.com>
	<1101112947.3798.6.camel@biol102145.oulu.fi>
	<Pine.LNX.4.61.0411220922490.24431@gannet.stats>
	<Pine.LNX.4.61.0411251032450.25900@gannet.stats>
Message-ID: <Pine.LNX.4.61.0412041945110.14294@gannet.stats>

This is now solved in R-devel: it runs in the slowest scenario below with 
a startup time of about 2.5secs and no appreciable delay when running.

On Thu, 25 Nov 2004, Prof Brian Ripley wrote:

> On Mon, 22 Nov 2004, Prof Brian Ripley wrote:
>
> [...]
>
>> BTW, I believe running R 2.0.x from a CD will be a lot slower than 1.9.1
>> because of lazy loading and frequent file accesses: that's a theoretical 
>> issue we intend to address for 2.1.0, but not one anyone has yet commented 
>> that it is a problem.
>
> I collected some data (under Windows XP).
>
> On a modern desktop, running R from a CD-R or from a USB 2.0 thumbdrive was 
> perfectably acceptable, with startup times of about 5 secs and little delay 
> when running.
>
> On a 2.5year old laptop with a USB 1.1 port (but the same thumbdrive) it took 
> about 15secs to start and with frequent delays the first time an object was 
> used -- I would not find that tolerable.  The laptop's CD drive was slower 
> than the desktop and there were delays when it powered down, but it was 
> acceptable.
>
> This was less performance penalty than I was expecting, and less than I have 
> seen on a high-latency network file system. So it looks as if all we can do 
> is trade a slower startup time (by caching files) for removing hiatuses when 
> running.  (Caching the pkg.rdb and pkg.rdx files when a package is opened 
> would probably only take up a little over 1Mb in a typical session.)
>
> Writing to the thumbdrive took about 20mins, as R has so many small files
> and the drive has a VFAT file system.

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] Re: [R] Running R from CD?
Prof Brian Ripley