Intel Core 2 Quad Q9550S
Drops into a supported LGA 775 board as it is; check the board's CPU list. How to check.
Intel Core 2 Quad Q9550S: 4-core, 2.83 GHz, Yorkfield, LGA 775, 1333 MT/s FSB, 12 MB (2 x 6 MB) L2, 65 W TDP.
The Q9550 at 65 W, and the only S-suffix quad with the full 12 MB of L2 (2 x 6 MB). Clock and bus are unchanged: 2.83 GHz on 1333 MT/s, launched in Q1 2009. Where the standard Q9550 went through three steppings, the S came only as E0, sSpec SLGAE, CPUID 1067A, so the BIOS needs microcode for just one CPUID. Intel sets its Tcase, the limit at the heat spreader center, at 76.3 °C. VT-x and SSE4.1 are present. No Q9450S appears in Intel's spec update or on ARK; this is the nearest real part. The LGA 775 Xeon L3360 matches it in clock, cache and TDP.
| Family | Core 2 Quad |
|---|---|
| Codename | Yorkfield |
| Socket | LGA 775 |
| Cores / threads | 4 / 4 |
| Base clock | 2.83 GHz |
| Front-side bus | 1333 MT/s (333 MHz base clock) |
| Multiplier | 8.5x |
| L2 cache | 12 MB (2 x 6 MB) |
| TDP | 65 W |
| Process | 45 nm |
| Launch | Q1 2009 |
| Dual-socket capable | No |
| VT-x | Yes |
| SSE4.1 | Yes |
| Enhanced SpeedStep | Yes |
| Max case temperature | 76.3 °C |
| Voltage range (VID) | 0.85 V to 1.3625 V |
Steppings and microcode IDs
| Stepping | CPUID | sSpec |
|---|---|---|
| E0 | 1067A | SLGAE |
A BIOS needs a microcode update matching the CPUID (and, for Xeons, the LGA 771 platform ID). See LGA 771 Xeon microcode and how to read your stepping.
Mod notes
Native LGA 775, no mod: check that the board maker lists the Q9550S with the E0 stepping, and note the BIOS version. A board from before 45 nm quads may never get that entry, whatever its power delivery.