At work, I finally took the plunge into running a 64 bit host OS on my main desktop. I’ve been hesitant the past several months, but a 2GB memory upgrade (pushing me up to the magic 4GB) finally pushed me over the edge.
It’s not that you can’t use 4GB on a 32 bit windows install. Rather it had more to do with my hardware. I have an HP xw9300 workstation, which uses AMD Opterons over a hyper transport bus. What I didn’t realize is that the topology of the memory and the CPU’s is different from plain old SMP. In AMD’s picture, each CPU has it’s own memory banks, and pairs of CPU/Memory are connected to each other over the Hyper Transport bus.
That’s all fine and dandy, except that XP 32 bit doesn’t understand this topology. So installing 2GB on each CPU’s memory bank still only yielded a total of 2GB physical memory showing up in the task manager’s performance tab. Curiously the CPU-Z could see things just fine, and XP still seemed to understand that there were 2 physical CPU’s. I’ve been running XP for a while now.. makes me wonder what it’s been doing all this time.
Feels a little weird to me that we’ve finally hit the point where a fairly reasonable developer configuration can pass the 4GB barrier. Seems not too long ago that we were still dealing with 16bit legacy applications on a 32 bit platform.
Thankfully, this time around, the bit-doubling transition is much easier. On windows, as long as you have x64 drivers for your hardware, you’re set. Most apps, including 32 bit ones, worked out of the box on my new Server 2003 x64 install (I chose w2k3/x64 because I needed the nfs server). It’s certainly far less troublesome than the DOS to Win95 transition, with the mixing of real mode and protected mode programs.
The only app that doesn’t work is Rhapsody.. and I’ve read on their forums that it doesn’t work on XP/x64 either. There’s no reason why this program shouldn’t work. It’s probably just something really dumb that hopefully they’ll fix very soon. Fortunately, the Rhapsody player engine still appears to work, so I can at least use yotta music to stream Rhapsody to work.