Posted by
Jeff Brandenburg on
URL: http://imagej.273.s1.nabble.com/Advices-on-computer-hardware-tp3701254p3701256.html
On Oct 20, 2006, at 8:51 AM, Frederick Ross wrote:
> The Macs are pretty, but if you intend to write your own code, they're
> very hell to program on. I keep a Linux installation next to OS X on
> my Powerbook for this purpose, but I unfortunately use MATLAB quite a
> bit at the moment and their Linux version is only for x86
> architectures. You'll get a really pretty computer for the price from
> Apple, but you'll get every bit as much computer for half the price
> from one of the PC vendors. Also, OS X doesn't manage memory well, so
> you will have to restart from time to time to clear it out if you're
> going through large datasets. Linux is in many ways a better option,
> unless you're attached to OsiriX. 2D graphics in Java at this point
> is much slower on OS X than on Linux, though I think that's supposed
> to be rectified soon. ImageJ certainly feels faster on Linux.
To amplify previous replies, Java on a G5 or Core Duo Mac is very much
faster than Java on a G4. I've just replaced my "old Powerbook" (a
667MHz G4) with a Core Duo 1.83GHz MacBook, and I'm seeing up to a
tenfold improvement in performance for heavily compute- or memory-bound
Java tasks.
OS X does cache very aggressively when you have a lot of RAM, so it can
look like free memory is going away faster than you expect. I often
load a large MRI volume into IJ, reslice it, save the resliced stack,
and ship the new stack across the network. Saving the stack is limited
by disk speed -- but then transferring it across the network requires
NO disk activity, because IT'S ALL STILL CACHED. As someone else
pointed out, when a process needs more working memory, this cached data
can be discarded with no overhead. So, yes, OS X often reports very
little free RAM -- but this is a *good* thing. You still don't see
many page-ins/outs, and that's the critical metric.
It's also worth pointing out again that, while the cheapest PC is
certainly less expensive than the cheapest Mac, comparably-configured
Macs and name-brand PCs are quite close in cost. And, for US$79, you
can buy a copy of Parallels, and then you can run OS X and Linux
simultaneously. Or, if you really, really hate OS X, you could just
boot straight into XP. :-)
--
-jeffB (Jeff Brandenburg, Duke Center for In-Vivo Microscopy)