Intel P45 Express in Detail
Intel's P45 Express chipset is part of the new Pxx naming system that Intel has come up with and is a member of the P4x series chipsets which automatically includes 1600MHz FSB support, so all the Core 2 series of CPU's (including the Intel QX9770) will work on any P45 based motherboard.
First off we will take a look at the major upgrades to the chipset. First up the PCI Express specification has been revised to support PCIe 2.0. P45 gets a total of 16 lanes on its Northbridge for the Graphics system; however, Intel has not limited the P45's Crossfire support like it did on the P35. As most will remember, Crossfire setup on the P35 chipset was limited to a single PCIe x16 slot and a PCIe x4 slot that could take a second graphics card. While this may sound reasonable, the x4 slot was run by combining 4 of the 6 lanes from the ICH8 Southbridge, which means the link between the second graphics card was limited to 2GB/s transfer protocol of the DMI interface that Intel uses to connect the North and Southbridge.
Now things have gone a bit further, Intel has taken a page from its older 975X chipset. It is up to the motherboard manufacturer to support Dual Graphics slots but if they do, the P45 can split the single PCIe x16 lane down to two PCIe x8 slots supporting PCIe 2.0 specs. This makes a more balanced system as both graphics cards get the same bandwidth and both are connected direct to the Northbridge, which also means a faster setup than the previous P35 16/4 setup with less latency. The good news is that ATI CrossfireX dual graphics technology support is still supported as well.
Next we move to the memory controller. P35 was the first chipset from Intel to support both DDR2 and DDR3 memory controllers on the one chip. X38 and X48 also does this as does the P45, but something has changed. While X38 and X48 only officially support a maximum of DDR2-800 modules, P45 as gone one step further and officially support DDR2-1066 modules natively, this makes the DDR2 support on P45 superior the X38 and X48 chipsets. It also proves Intel hasn't quite finished with DDR2, though the word on the street is that this will be the last chipset from Intel to have a DDR2 memory controller. In terms of DDR3 support, P45 supports up to a maximum of 1333MHz DDR3, XMP is not supported on this chipset as this is what Intel uses to separate the X38 and X48 from the more mainstream chipsets.
With the new Northbridge comes a new Southbridge, while ICH9 isn't that old, and its feature set is extremely extensive, there is always room for expansion. ICH10 is now making its way in with the P45 and hopefully we will see it on new X48 boards.
Now we have covered the basics of the P45 Express chipset, let's move on and take a close look at the motherboards from GIGABYTE.