Intel Xeon E5420
Runs in an LGA 775 board only with the adapter sticker, the socket tabs removed and BIOS support for its core. How the mod works.
Intel Xeon E5420: 4-core, 2.5 GHz, Harpertown, LGA 771, 1333 MT/s FSB, 12 MB (2 x 6 MB) L2, 80 W TDP.
The E5420 uses a half multiplier: a 333 MHz bus clock times 7.5 gives its 2.5 GHz, and the bus is quoted as 1333 MT/s because it moves four transfers per clock. Otherwise it is standard 80 W Harpertown: 45 nm, 12 MB of L2 split 2 x 6 MB, SSE4.1, VT-x and Enhanced SpeedStep. Tcase is 67 °C at the center of the lid; VID runs 0.85 V to 1.35 V. Lid codes are SLANV for the C0 stepping, CPUID 10676, and SLBBL for E0, CPUID 1067A. In an old desktop it is a mid-range quad that an ordinary quad-core cooler can handle.
| Family | Xeon |
|---|---|
| Codename | Harpertown |
| Socket | LGA 771 |
| Cores / threads | 4 / 4 |
| Base clock | 2.5 GHz |
| Front-side bus | 1333 MT/s (333 MHz base clock) |
| Multiplier | 7.5x |
| L2 cache | 12 MB (2 x 6 MB) |
| TDP | 80 W |
| Process | 45 nm |
| Launch | Q4 2007 |
| Dual-socket capable | Yes |
| VT-x | Yes |
| SSE4.1 | Yes |
| Enhanced SpeedStep | Yes |
| Max case temperature | 67 °C |
| Voltage range (VID) | 0.85 V to 1.35 V |
Steppings and microcode IDs
| Stepping | CPUID | sSpec |
|---|---|---|
| C0 | 10676 | SLANV |
| E0 | 1067A | SLBBL |
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
Closest LGA 775 desktop chip: Core 2 Quad Q8300 (2.5 GHz, 1333 MT/s, 4 MB (2 x 2 MB)). A board that lists it is the best sign it can run the Xeon E5420.
The board must already run 45 nm Core 2 chips; then add the adapter sticker, remove the socket's two key tabs, and flash microcode for CPUIDs 10676 and 1067A with the LGA 771 platform ID. Socket pins bend at the lightest touch, so keep the blade on the plastic tabs and well away from the contact field.
Check a specific board with the LGA 771 to 775 compatibility checker.