Intel Core 2 Quad Q9550
Drops into a supported LGA 775 board as it is; check the board's CPU list. How to check.
Intel Core 2 Quad Q9550: 4-core, 2.83 GHz, Yorkfield, LGA 775, 1333 MT/s FSB, 12 MB (2 x 6 MB) L2, 95 W TDP.
The only Core 2 Quad in this database with three steppings, which is reason enough to read the lid before touching the BIOS: C0 (SLAN4, CPUID 10676), C1 (SLAWQ, CPUID 10677) and E0 (SLB8V, CPUID 1067A). SLAN4 is not in an Intel spec update, so its CPUID is mapped from the stepping, and the archived CPU-World page for it gives no TDP. The rest is straightforward: 2.83 GHz from an 8.5 multiplier on the 1333 MT/s bus, 12 MB of L2 as 2 x 6 MB, 95 W, Tcase 71.4 °C, launched in Q1 2008. Among Core 2 Quads, leaving out the Extreme parts, only the Q9650 is clocked higher, and VT-x and SSE4.1 round it out.
| 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 | 95 W |
| Process | 45 nm |
| Launch | Q1 2008 |
| Dual-socket capable | No |
| VT-x | Yes |
| SSE4.1 | Yes |
| Enhanced SpeedStep | Yes |
| Max case temperature | 71.4 °C |
| Voltage range (VID) | 0.85 V to 1.3625 V |
Steppings and microcode IDs
| Stepping | CPUID | sSpec |
|---|---|---|
| C0 | 10676 | SLAN4 |
| C1 | 10677 | SLAWQ |
| E0 | 1067A | SLB8V |
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
Nothing to cut or patch on the CPU side. Board support lists may split the Q9550 by stepping, so match the line to your chip, C0, C1 or E0, and its BIOS version; before updating, back up the existing BIOS and keep the machine on steady power.