The Intel Core i5-661 was a desktop processor with 2 cores, launched in January 2010, at an MSRP of $196. It is part of the Core i5 lineup, using the Clarkdale architecture with Socket 1156. Thanks to Intel Hyper-Threading the core-count is effectively doubled, to 4 threads. Core i5-661 has 4 MB of L3 cache and operates at 3.333 GHz by default, but can boost up to 3.6 GHz, depending on the workload. Intel is building the Core i5-661 on a 32 nm production process using 382 million transistors. The multiplier is locked on Core i5-661, which limits its overclocking capabilities.
With a TDP of 87 W, the Core i5-661 consumes a good deal of power, so decent cooling is needed. Intel's processor supports DDR3 memory with a dual-channel interface. The highest officially supported memory speed is 1333 MT/s, but with overclocking (and the right memory modules) you can go even higher. For communication with other components in the computer, Core i5-661 uses a PCI-Express Gen 2 connection. This processor features the Intel HD integrated graphics solution.
Hardware virtualization is available on the Core i5-661, which greatly improves virtual machine performance. Additionally, IOMMU virtualization (PCI passthrough) is supported, so that guest virtual machines may directly use host hardware.