LOL, no compatibility, no benchmarks
?Software IOTLB ? Intel® EM64T does not support an IOMMU in hardware while AMD64 processors do. This means that physical addresses above 4GB (32 bits) cannot reliably be the source or destination of DMA operations. Therefore, the Red Hat Enterprise Linux 3 Update 2 kernel "bounces" all DMA operations to or from physical addresses above 4GB to buffers that the kernel pre-allocated below 4GB at boot time. This is likely to result in lower performance for IO-intensive workloads for Intel® EM64T as compared to AMD64 processors.?
Important: Although Windows Server 2003 for 64-Bit Extended Systems supports both AMD Opteron processors and Intel Xeon with Intel Extended Memory 64 Technology (EM64T) processors, this evaluation version predates Xeon processors and supports only AMD Opteron processors. Future beta versions will be released that support both AMD Opteron and Intel Xeon with Intel Extended Memory 64 Technology (EM64T).
In my words -> Intel didn't make a complete copy of AMD64, that's why Windows XP for 64-bit extended systems DOES NOT support Nocona YET.
?Software IOTLB ? Intel® EM64T does not support an IOMMU in hardware while AMD64 processors do. This means that physical addresses above 4GB (32 bits) cannot reliably be the source or destination of DMA operations. Therefore, the Red Hat Enterprise Linux 3 Update 2 kernel "bounces" all DMA operations to or from physical addresses above 4GB to buffers that the kernel pre-allocated below 4GB at boot time. This is likely to result in lower performance for IO-intensive workloads for Intel® EM64T as compared to AMD64 processors.?
Important: Although Windows Server 2003 for 64-Bit Extended Systems supports both AMD Opteron processors and Intel Xeon with Intel Extended Memory 64 Technology (EM64T) processors, this evaluation version predates Xeon processors and supports only AMD Opteron processors. Future beta versions will be released that support both AMD Opteron and Intel Xeon with Intel Extended Memory 64 Technology (EM64T).
In my words -> Intel didn't make a complete copy of AMD64, that's why Windows XP for 64-bit extended systems DOES NOT support Nocona YET.