Intel Core 2 Quad Q9550S socket: LGA 775
The Intel Core 2 Quad Q9550S uses the LGA 775 socket. It is a 65 W quad core Yorkfield desktop part at 2.833 GHz with 12 MB of L2 cache for efficient towers.
- Socket
- LGA 775
- Launched
- January 2009
- Cores and threads
- 4 and 4
- Base power
- 65 W
- Codename
- Yorkfield
- Segment
- Desktop
- Family
- Intel Core 2 Quad
- Clocks
- 2.83 GHz
Intel Core 2 Quad Q9550S specifications
| Cores | 4 |
|---|---|
| Threads | 4 |
| Core architecture | Yorkfield cores on 45 nm |
| Clock | 2.833 GHz (no turbo) |
| Front side bus | 1333 MT/s |
| Cache | 12 MB L2 (2 × 6 MB) |
| Thermal design power | 65 W |
| Manufacturing process | 45 nm |
| Memory support | DDR2 or DDR3, two channels (board dependent) |
| PCI Express | PCIe Gen 2 from the board chipset |
| Integrated graphics | None (discrete graphics) |
| Multiplier | Locked |
| Package | LGA775 |
Motherboard and chipset compatibility
Intel Core 2 Quad Q9550S needs a motherboard with a LGA 775 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| Intel 4 series | X48, P45, G45, G41 | Works out of the box |
| Intel 3 series | X38, P35, G33, G31 | Needs a BIOS update 45 nm Yorkfield quads boot on 3 series boards that list them, after a BIOS update. |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 775.
LGA 775 at a glance
| Type | LGA, 775 contacts |
|---|---|
| Package size | 37.5 × 37.5 mm |
| Introduced | 2004 |
| Memory | DDR, DDR2 or DDR3, depending on the motherboard chipset |
| Cooler mounting holes | 72 × 72 mm |
What the Core 2 Quad Q9550S is
The Intel Core 2 Quad Q9550S is a quad core Yorkfield desktop processor from January 2009. It runs four cores at 2.833 GHz with no turbo and no Hyper-Threading, so 4 cores give 4 threads. Cache is 12 MB of L2 in two 6 MB dies on a 45 nm process. Power is rated at 65 W with a 1333 MT/s front side bus.
The trailing S marks low power at 65 W against 95 W on the standard Q9550 at the same clocks and cache. Board tables confirm 2.83 GHz with 12 MB and 65 W. Against the Q9505S it doubles cache at the same 65 W.
There is no graphics on the CPU. Display needs a discrete card.
Socket and motherboard compatibility
The Core 2 Quad Q9550S fits LGA 775 with 775 lands. Intel 4 series boards boot Yorkfield natively, while 3 series boards need a listed BIOS.
The Socket vs chipset: what decides whether a CPU works guide covers pairing rules, and the Intel Core 2 Quad Q6600 page shows a Kentsfield quad on the same socket.
Memory, PCIe and cooling
Memory is DDR2 or DDR3 in two channels depending on the board chipset.
The 1333 MT/s front side bus links the CPU to the chipset. PCIe Gen 2 slots hang off the chipset.
Cooling is a 65 W class tower on the 72 × 72 mm pattern.
Upgrade paths
On LGA 775 the upgrade is the Q9650 on the same board. Beyond LGA 775 a move to LGA 1156 needs a new board.
Frequently asked questions
What socket does the Core 2 Quad Q9550S use?
LGA 775, the 775-land package. Intel 4 series boards boot it natively, 3 series after a BIOS update.
How many cores does the Core 2 Quad Q9550S have?
Four cores and four threads at 2.833 GHz with 12 MB of L2 cache in two dies.
What memory works with the Core 2 Quad Q9550S?
DDR2 or DDR3 in two channels depending on the board chipset.
Sources and verification
Facts last checked against these sources on . Page last edited on .