st: re: Memory, Stata 10, and 32-bit XP

[Kit Baum <kitbaum@mac.com>]

Fred said

Our group is switching over to the Power Mac for some of the reasons
enumerated by Kit. We are wondering if Kit (and others) have
experience with the extent to which performance is boosted (+ or -0)
by Raid 0, 1 or 5) using Stata, and if there are any recommendations.


Congratulations to Fred and his outfit for a sensible choice. He  
should not speak of the "Power Mac", though, unless they've gotten a  
real deal on obsolete hardware. Modern Macs (for a while now) run on  
the same Intel chips as many popular PCs. My laptop, for instance, is  
an Intel Core Duo (sadly, a month later, they switched to the Intel  
Core 2 Duo, a bit better chip). "Power Mac" to most Mac people refers  
to "PowerPC" or "PPC", the Motorola/IBM chip family that Apple  
abandoned in search of better performance. "Intel Mac" refers to any  
machine you can buy today.

I don't think that RAID has much if anything to do with Stata  
performance. In our department we have an Xserve server with RAID 5  
(actually, a PowerPC G5) that runs Stata 10. But the only time that  
Stata will be talking to the RAID device is when it is using or  
saving a dataset. Otherwise any calls for the hard disk (e.g. from  
Unix's virtual memory requirements, tempfiles, etc.) will be using  
the system disk, which is not RAID but inboard. (We have an Apple  
xRAID which is an external unit, attached by some very expensive  
cables which facilitate high-speed data transfer). Stata's  
performance, after all, is usually gauged by what it does with the  
data once it has loaded it into memory, not how long it takes to read  
it from the disk. Therefore whether it is reading from RAID disk or  
not should not affect Stata's performance in, e.g., running  
regressions or doing data transformations, reshapes, etc.

There are many advantages to using Mac OS X, but the most obvious  
overlap significantly with the advantages posed by other Unix flavors  
or Linux, as all are based on essentially the same tried and tested  
code. The Mac OS X environment is certainly easier to use and manage  
than Unix/Linux, and more Windows-like. But for someone who must have  
a Windows platform, the option to dual-boot into Linux allows access  
to those advantages.

Someone from StataCorp will no doubt correct these statements if they  
are erroneous or misleading.

Kit

Kit Baum, Boston College Economics and DIW Berlin
http://ideas.repec.org/e/pba1.html
An Introduction to Modern Econometrics Using Stata:
http://www.stata-press.com/books/imeus.html


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