Intel Core 2 Extreme QX6850
Drops into a supported LGA 775 board as it is; check the board's CPU list. How to check.
Intel Core 2 Extreme QX6850: 4-core, 3.0 GHz, Kentsfield, LGA 775, 1333 MT/s FSB, 8 MB (2 x 4 MB) L2, 130 W TDP.
The QX6850 is the Kentsfield Extreme moved to the faster bus. Where the QX6700 and QX6800 sit on the older, slower FSB, this one runs 1333 MT/s with a multiplier of 9: a 333 MHz bus clock times 9 gives 3.0 GHz. That makes it the newest and quickest of the three Kentsfield Extremes here, launched Q3 2007. Everything else is familiar: 8 MB of L2 across two dies, 130 W TDP, a Tcase of 64.5 °C, VID from 0.85 V to 1.5 V (VID is the voltage the chip asks the board for). Only one stepping shipped, G0, as SLAFN with CPUID 6FB. In practice the bus decides where it can live more than the clock does.
| Family | Core 2 Extreme |
|---|---|
| Codename | Kentsfield |
| Socket | LGA 775 |
| Cores / threads | 4 / 4 |
| Base clock | 3 GHz |
| Front-side bus | 1333 MT/s (333 MHz base clock) |
| Multiplier | 9x |
| L2 cache | 8 MB (2 x 4 MB) |
| TDP | 130 W |
| Process | 65 nm |
| Launch | Q3 2007 |
| Dual-socket capable | No |
| VT-x | Yes |
| SSE4.1 | No |
| Enhanced SpeedStep | Yes |
| Max case temperature | 64.5 °C |
| Voltage range (VID) | 0.85 V to 1.5 V |
Steppings and microcode IDs
| Stepping | CPUID | sSpec |
|---|---|---|
| G0 | 6FB | SLAFN |
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
No adapter, but it needs a board that runs a 1333 MT/s bus, lists the QX6850 (G0) on its CPU support page and has power delivery meant for 130 W. A board validated only for slower-bus quads may never get support, so read the list before you buy the chip or the board.