Intel Xeon X5355
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 X5355: 4-core, 2.66 GHz, Clovertown, LGA 771, 1333 MT/s FSB, 8 MB (2 x 4 MB) L2, 120 W TDP.
Here clock wins over efficiency: the X5355 runs 2.66 GHz from a 1333 MT/s bus and an 8x multiplier, with a 120 W TDP where the E-series Clovertowns sit lower. That rating matters in an LGA 775 board, because the voltage regulators and the cooler both have to handle it. ARK allows a Tcase of 70 °C at the center of the lid and a VID range of 1 V to 1.5 V. Cache is the usual 8 MB, split across two dies. It has Enhanced SpeedStep and VT-x, no SSE4.1. A fast 65 nm quad for an older board with strong power delivery, if you have the cooling.
| Family | Xeon |
|---|---|
| Codename | Clovertown |
| Socket | LGA 771 |
| Cores / threads | 4 / 4 |
| Base clock | 2.66 GHz |
| Front-side bus | 1333 MT/s (333 MHz base clock) |
| Multiplier | 8x |
| L2 cache | 8 MB (2 x 4 MB) |
| TDP | 120 W |
| Process | 65 nm |
| Launch | Q4 2006 |
| Dual-socket capable | Yes |
| VT-x | Yes |
| SSE4.1 | No |
| Enhanced SpeedStep | Yes |
| Max case temperature | 70 °C |
| Voltage range (VID) | 1 V to 1.5 V |
Steppings and microcode IDs
| Stepping | CPUID | sSpec |
|---|---|---|
| B3 | 6F7 | SL9YM, SLAC4 |
| G0 | 6FB | SLAEG |
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
Before cutting anything, make sure the board runs Kentsfield quads and that its power delivery can feed a 120 W chip, then fit the sticker, remove the two socket tabs, and add microcode for 6F7 and 6FB with the LGA 771 platform ID. A careless cut can bend socket pins, and bent LGA pins are slow, fiddly work to straighten.
Check a specific board with the LGA 771 to 775 compatibility checker.