The EPIC architecture uses long CPU instructions that resemble multiple RISC instructions strung together. These instructions are run simultaneously down multiple pipelines within the CPU, allowing IA-64 CPUs to compute multiple instructions per clock cycle. The Itanium will be capable of running up to 20 instructions per clock cycle. IA-64 instructions are bundled together when originally compiled, simplifying the process of running multiple instructions at once. In contrast, x86 instructions are compiled serially, so in order to make use of multiple pipelines, the CPU essentially has to predict or guess what can run simultaneously down each of its pipelines. When an x86 CPU is right, multiple instructions get executed per clock. When it is wrong, the extra executed instructions are wasted.
So by setting up what instructions can be run simultaneously when a program is originally compiled, the EPIC architecture is capable of consistently running more operations per clock than an x86 CPU. This does put a significant burden on the EPIC compiler, but EPIC compilers have been in development for over a year, so while they may not yet be perfect, they have had time to mature. EPIC performance will most likely improve as compilers mature even more. Even today, x86 compilers are improving.
Intel has a significant amount of industry support lined up for IA-64. SGI and HP will be migrating away from their own architectures over to IA-64 powered systems. SGI supposedly has plans for systems with up to 512 processors. Such SGI systems will most likely use Linux-64 with added IRIX technology. Microsoft is doing a Win64 port of Windows 2000. IBM and SCO are porting Monterey. HP is porting HP-UX. And Novell is porting Modesto. The only major player not on the IA-64 bandwagon is Sun, who is likely to be IA-64's biggest competitor.
In addition to the OS support, Intel is wooing Independent Software Vendors (ISV) to port their 64-bit applications to IA-64 operating systems. Intel has set up a 250 million dollar ISV fund to entice and help ISVs develop software for IA-64. Oracle, SAP, PeopleSoft, Baan, Microsoft SQL Server, IBM DB2, and others are expected to have IA-64 products.