However, there are 64bit processors, which do not have any problem with the OS and other software support. of course, we are talking about the server veterans: RISC solutions from IBM, Sun and Compaq.

IBM PowerPC processor family also known as Power4/Power4+ are actually the today’s biggest competitors to Intel Itanium 2. They used to be the first 0.13micron 64bit processor in the market, and since then IBM has been working on the improvement of their technical specs. So, today we have a relatively inexpensive processor with two physical dies, 1.4MB-1.5MB L2 cache and on-die North Bridge. The processor supports pretty exotic approach: it combines up to 5 instructions into a group and then processes it as a solid parameter. On the one hand, it makes the work much simpler, but on the other, you will have to return far back if something happens. Besides, this limitation tells in far not the best way on the possibility to parallelize operations, thus reducing the overall algorithm flexibility.

We can’t help mentioning one more PowerPC representative: 64bit PowerPC 970 targeted for a totally different market segment. This processor is designed for PowerMac computers and is none other but a cut-down Power4 version featuring Altivec SIMD instructions from Motorola. In fact, it is a nearly ideal replacement for PowerPC G4 and G4+. It is a very economical solution, which also boasts the core clock potential beyond 2GHz.