Intel 82801GR (ICH7-R, 975X)
The 975X chipset's ICH7R Southbridge offers four USB 2.0 controllers with two ports each, and four Serial ATA/300 ports with Intel's flexible Matrix Storage Technology, which supports various RAID modes.
ICH7-R is almost an oldie, as it was released almost one and a half years ago. Yet, it remains sufficiently up to date for most applications. Four Serial ATA ports are still enough, especially since ICH7 still offers one ultraata/100 channel (for one or two devices), unlike ICH8. Ultraata is important for older hard drives you may have, or for installing optical drives.
ICH7 supports up to eight USB 2.0 ports. The Universal Serial Bus works on a controller base as well, and these eight ports are provided by four root controllers. Most motherboards offer two or maybe three USB 2.0 port pairs at the connector panel on the back side; additional USB 2.0 headers are usually located somewhere on the motherboard and can be utilized by installing appropriate headers.
While adding more Serial ATA ports and another USB 2.0 controller to ICH8 doesn't seem to be a big deal, more changes were made by the Intel engineers: ICH8 is superior to ICH7 in all of our I/O benchmarks and in most of the SATA throughput benchmarks.
There are even more differences when we look at USB 2.0 performance; if you attach only a single drive, there is only very little difference between the three contenders. However, both ICH8 and nforce 6 MCP sustain higher throughput per device (almost 30 MB/s instead of ~20 MB/s when two drives are copying data).