Just a quick correction:
Quote:
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Before I get started, I wanted to take a moment and explain what 64-bit computing is and why it is so significant. As you probably know, computers process instructions in binary format. Each bit is capable of processing one binary instruction (zero or one) per clock cycle. Most of the PCs that are currently on the market have 32-bit processors, meaning that they can process 32 binary instructions per clock cycle.
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This is wrong. An instruction on a CISC arch like x86 has a variable number of bits per instruction, MMX instructions are far more than 32-bits, and the smallest instructions I believe are above 8-bits. Modern CPU's don't get anywhere close to the 1 instruction per clock cycle, typically more like .3 instructions per clock cycle (due to cache fetches, reads from ram, etc). Also, 64-bit instructions are typically much larger than their 32-bit counterparts, due to it being a 64-bit operation. So some programs (which reference a lot of memory addresses by pointers) will even run slower in 64-bit mode than in 32-bit mode, due to the extra memory accesses eating cache area.
In my opinion the primary reason to move to the AMD64 platform today is twofold:
1. The Athlon64 is a well built processor, the on-chip memory controller, coupled with the much shorter pipeline makes it an excellent performer.
2. 4 gigs of ram as a real bottleneck is coming closer and closer. Due to Virtual Memory (which is in all modern operating systems), a 32-bit system can only use 2-3 gigs of actual ram per process (so a big database on Win32 for example can't use any more than 2gigs of ram).
Also, on an aside, thanks to the open-source nature of linux and most of the software that runs on linux, you can run in pure 64-bit mode very easily. The only thing that I miss on a regular basis is the WMV codec for playing videos and the flash plugin. Other than those two things, everything is pure 64-bit for me.