Intel X48 Express

OK, we had almost nothing to say about two new chipsets from NVIDIA. And the top product from Intel launched in spring 2008 has even fewer characteristics worth mentioning here. Functionality of the X48 can be described with a single phrase: it's Intel X38 minus DDR2 support plus official support for 1600 MHz FSB. Let's enumerate the key features of the X48:

• Support for all Celeron, Pentium, and Core 2 (Duo/Quad/Extreme) processors with 800-1600 MHz FSB, including models on Wolfdale/Yorkfield (Penryn) cores
• Dual-channel DDR3-800/1066/1333 memory controller, up to 4 DIMM modules with the total size of up to 8 GB (without ECC), Fast Memory Access and Flex Memory technologies, as well as XMP support, including memory operating at higher frequencies
• 2 x PCI Express 2.0 x16 slots
• DMI bus (~2 GB/s bandwidth) to the ICH9 Southbridge
• Up to six PCIEx1 ports
• Up to four PCI slots
• 4/6 (4 in ICH9, 6 in ICH9R) Serial ATA II ports for 4/6 SATA300 devices (SATA-II, the second generation of the standard), AHCI and NCQ (only for ICH9R), hot plug, eSATA, and port splitters
• RAID (ICH9R only) 0, 1, 0+1 (10) and 5 with Matrix RAID function (the same array of drives can be used in several RAID modes - for example, two drives may form RAID 0 and RAID 1, each array will use its own part of the disks)
• 12 x USB 2.0 devices supporting hot plug
• Gigabit Ethernet MAC controller and a special interface (LCI/GLCI) for a PHY controller (i82566 for Gigabit Ethernet, i82562 for Fast Ethernet)
• Intel Turbo Memory support
• High Definition Audio (7.1)
• Binding for low-speed and outdated periphery, other things

We've said everything about support for new processors above. We can add a few words about memory. You might have already read about XMP profiles, stored in the unused SPD area, which allow to specify an overclocked mode easily, taking into account such nuances as increased voltage. XMP profiles do not depend on a chipset, of course (we've seen DDR3 with XMP work on the Intel X38-based motherboard). But Intel stresses that the X48 is the first chipset certified for this technology. It's important, because it allows to announce official support for DDR3-1600 (and even faster modes), as in case of nForce 790i. But memory modules must have extended SPD - with XMP or EPP 2.0 for Intel and NVIDIA chipsets correspondingly. I repeat that X48 uses the old ICH9 as its Southbridge.

What concerns heat dissipation, the X48 (and X38) are not doing as good as usual Intel 3x chipsets: the hot PCI Express 2.0 controller makes its big contribution here. The difference is noticeable in numbers (X48 TDP - 30.5 W, X38 - 26.5 W, P35 - 14.5 W, G33 - 16 W) and necessary cooling systems. At the same time, heat release of the nForce 790i chipsets is still noticeably higher, although we have to rely on our tests alone here.