The 660 Model 6H1 (7026-6H1) offers large memory capacity and up to six advanced 64-bit RS64 IV microprocessors running at up to 750 MHz for high levels of performance and price with performance. The Model 6H1 also offers one-, two- and four-way 64-bit RS64 IV microprocessors running at 600 MHz. The processors utilize innovative copper and silicon-on-insulator (SOI) technology. The result is high performance with less power consumption and lower heat generation for higher levels of reliability and system availability. The rack-drawer design of the Model 6H1 provides ease of growth in processor as well as I/O and memory capacity. It includes a standard rack-mounted processor drawer and an I/O drawer with 14 hot-plug PCI slots for configuration flexibility.