Intel Core i5-661 socket: LGA 1156
The Intel Core i5-661 uses the LGA 1156 socket. It is an 87 W dual core Clarkdale desktop part at 3.333 GHz with Turbo Boost to 3.6 GHz, Hyper-Threading, 4 MB of L3 cache and faster graphics than the 660.
- Socket
- LGA 1156
- Launched
- January 2010
- Cores and threads
- 2 and 4
- Base power
- 87 W
- Codename
- Clarkdale
- Segment
- Desktop
- Family
- Intel Core i5
- Clocks
- 3.33 / 3.6 GHz
Intel Core i5-661 specifications
| Cores | 2 |
|---|---|
| Threads | 4 |
| Core architecture | Clarkdale cores on 32 nm |
| Clocks | 3.333 GHz base, 3.6 GHz Turbo Boost |
| Cache | 512 KB L2 (2 × 256 KB), 4 MB shared L3 |
| Processor base power (TDP) | 87 W |
| Manufacturing process | 32 nm CPU, 45 nm graphics |
| Memory support | DDR3-1333, two channels |
| PCI Express | PCIe 2.0 x16 from the package |
| Integrated graphics | HD Graphics, higher clocked than i5-660 |
| Multiplier | Locked |
| Package | LGA1156 |
Motherboard and chipset compatibility
Intel Core i5-661 needs a motherboard with a LGA 1156 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| 5 series with graphics | H55, H57, Q57 | Works out of the box |
| P55 performance | P55 | Works out of the box Onboard video ports stay dark on P55. Use a separate graphics card. |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 1156.
LGA 1156 at a glance
| Type | LGA, 1,156 contacts |
|---|---|
| Package size | n/a |
| Introduced | September 2009 |
| Memory | DDR3-1066 and 1333, two channels, up to 16 GB |
| Cooler mounting holes | 75 × 75 mm |
What the Core i5-661 is
The Intel Core i5-661 is a dual core Clarkdale desktop processor from January 2010. It matches the i5-660 at 3.333 GHz base with Turbo Boost to 3.6 GHz and 4 MB of shared L3 cache, but pairs it with higher clocked HD Graphics for 87 W instead of 73 W. A bit-tech launch review covers the 661 alongside the i3-530.
The 661 suits towers that use integrated graphics for media playback while keeping a discrete slot free. Against the 660 it trades 14 W for graphics speed at identical CPU clocks.
Memory is DDR3-1333 in two channels.
Socket and motherboard compatibility
The Core i5-661 fits LGA 1156 with 1156 lands. H55, H57 and P55 boards boot it natively with a 2010 BIOS. The 87 W rating wants solid delivery on value boards.
The Socket vs chipset: what decides whether a CPU works guide covers pairing rules, and the Intel Pentium G6950 page shows the Pentium alternative.
Memory, PCIe and cooling
Memory is DDR3-1333 in two channels up to 16 GB.
PCIe 2.0 x16 comes from the package.
Cooling is a 73 W class sink at minimum, with the 87 W rating favoring a tower with margin.
Upgrade paths
On LGA 1156 the upgrade is the 670 or 680, or a Lynnfield quad on P55 boards. Beyond LGA 1156 a move to Sandy Bridge needs a new board.
Frequently asked questions
What socket does the Core i5-661 use?
LGA 1156, the 1156-land package on 5 series boards.
How many cores does the Core i5-661 have?
Two cores and four threads at 3.333 GHz base with Turbo Boost to 3.6 GHz, with 256 KB of L2 per core and 4 MB of shared L3 cache.
What memory works with the Core i5-661?
DDR3-1333 in two channels.
Sources and verification
Facts last checked against these sources on . Page last edited on .