Intel Core 2 Extreme QX6800
Drops into a supported LGA 775 board as it is; check the board's CPU list. How to check.
Intel Core 2 Extreme QX6800: 4-core, 2.93 GHz, Kentsfield, LGA 775, 1066 MT/s FSB, 8 MB (2 x 4 MB) L2, 130 W TDP.
One multiplier step above the QX6700 on the same bus, the QX6800 runs an 11x multiplier for 2.93 GHz and keeps the 8 MB of L2 and the 130 W rating. It exists in two steppings (a stepping is a silicon revision): B3 as SL9UK and G0 as SLACP. The G0 entry carries a documentation slip. Intel's Q6000 spec update prints CPUID 06F7h for SLACP, while G0 is 06FBh everywhere else, including that same document's other G0 sSpecs, so the table lists 6FB and treats the print as a typo. The CPUID is the number the chip reports so the BIOS can load matching microcode, which is why the mix-up matters. For an old build it is a hot, quick 65 nm quad that needs a serious cooler.
| Family | Core 2 Extreme |
|---|---|
| Codename | Kentsfield |
| Socket | LGA 775 |
| Cores / threads | 4 / 4 |
| Base clock | 2.93 GHz |
| Front-side bus | 1066 MT/s (267 MHz base clock) |
| Multiplier | 11x |
| L2 cache | 8 MB (2 x 4 MB) |
| TDP | 130 W |
| Process | 65 nm |
| Launch | Q2 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 |
|---|---|---|
| B3 | 6F7 | SL9UK |
| G0 | 6FB | SLACP |
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, so the work is all on paper: find the QX6800 on the board's CPU list, see whether the list treats B3 and G0 separately, and note the BIOS release that adds it. Before you flash that release, save the current BIOS and keep the machine on steady power.