As long as you have 4 GB in your machine, stay at 32Bit. STart thinking about 64 Bit at 8GB. Reason: 64Bit programs have larger pointers, and need between 10 and 35% more free RAM than a corresponding 32Bit App. Running the CPU in 64Bit gives it more and larger registers: great if you often work with longlong [money...] datatype, but in other cases not really that important. Depending on the kind of app you have somewhere between 90% and 120% of the speed of the 32Bit app - as long as the 32Bit app is not memory starved. Those apps get a great boost from 64Bit and RAM. This can be readily seen by graphic oriented apps as well as database apps - but probably not during dev time, as the loads tend to be minimalistic there. A single Quad core should be enough for a single dev - if need be, you can heighten the priority of 2 needed tasks and have 2 cores for background work. Have not really tested the doubling of the cores in the newer machines with the old PIV methods. For me the best reason to splurge on RAM is DiscCache and room for many VM's - especially if you need 32 (or even 16Bit) for some times more. And to be sure: there is no need for you to *depend* on any single 64Bit OS - Multiboot is a must for me. It gives me room to play and reminds you of good partition practices, separating your data files away form boot/OS partitions.

Feel free to ask on anything unclear - I know I sometimes write my text under some assumptions not voiced...

thomas

>I'm really in over my head on memory/OS stuff but definitely want to learn. If I have a single quad core processor, should I be using a 64bit OS ? Right now I'm running Win 7 Ultimate 32 bit with 4 gb. I am not sure if I need to be looking at a new box with 64 bit and multiple processors and 8gb + or just need to think about going to 64bit on this box and bump the memory.
>

>>You can use more memory, but only as a faster replacement for the swap file - you swap similar to the extended memory very late in DOS, but needed for the large version of Foxpro/Dos. Mostly depending on your video card you can expect up to 3.5 GB of main memory, but each process still has its 2GB (3GB with the large switch) limitation - but if you have such a beefy HW-system needing to work in 32Bit, perhaps running 3 32Bit-VM's in parallell on 64Bit base is a better solution ?
>>
>>regards
>>
>>thomas