There are a few additional controllers on the board, though. For example, ASUS engineers didn’t want to use the network controller integrated into the nForce Professional 2200 chipset. Instead, they integrated a Gigabit network controller from BROADCOM – PCI Express x1 BCM5751. Besides, ASUS K8N-DL is equipped with the additional Serial ATA RAID controller – Silicon Image SiI3114R, which implements the remaining four Serial ATA-I ports supporting RAID 0, 1, 0+1 and 5. The mainboard from ASUS also features two IEEE 1394 ports implemented via the Texas Instruments TSB43AB22A chip.
The most interesting features of ASUS K8N-DL mainboard are connected with the processors and memory support, of course. So, let’s dwell here for a while. The mainboard is equipped with two Socket 940 connectors, which allow installing one or two Opteron processors. The latest BIOS version at the time of this review – version 1004 – allows installing regular Opteron CPUs as well as dual-core ones.
There are memory slots next to both processor sockets: four DIMM slots next to the first one and two more DIMM slots next to the second one. Since Opteron processors feature a memory controller integrated into the CPU core, each of the CPUs in the dual-processor configuration can work with its own memory. However thanks to NUMA technology (Non-Uniform Memory Architecture) the two CPUs operate within the single address space. In other words, each processor can address the memory of the other CPU in the system via the HyperTransport bus between them. And no special tricks are necessary to make it happen. Moreover, each CPU doesn’t really care where the requested data is stored. Although you should definitely keep in mind that if the data is located in the other processor’s memory, the latency of the corresponding operation will be somewhat longer than in case the data were in the processor’s own memory.
The Opteron memory controllers work only with Registered DDR SDRAM. Therefore, large amounts of memory can be supported. ASUS K8N-DL with its 6 DIMM slots supports up to 24GB of memory (if you install 4GB Registered DIMMs, which are just about to appear in the market).
Also, just like in Socket 939 systems, the Opteron memory controller features dual-channel architecture. Therefore, the memory modules in your system should be installed in pairs, only in this case you will get the maximum performance. In case of a dual-processor configuration, you’d better use four identical memory modules and allocate the same amount of memory for each of the system CPUs. This will theoretically allow reaching the memory bandwidth of a quad-channel memory subsystem.