Intel Xeon E5420 socket: Socket 771
The Intel Xeon E5420 uses the Socket 771 socket. It is an 80 W quad-core Harpertown server part at 2.5 GHz with 12 MB of L2 cache for dual-processor racks.
- Socket
- Socket 771
- Launched
- November 2007
- Cores and threads
- 4 and 4
- Base power
- 80 W
- Codename
- Harpertown
- Segment
- Server
- Family
- Intel Xeon
- Clocks
- 2.5 GHz
Intel Xeon E5420 specifications
| Cores | 4 |
|---|---|
| Threads | 4 |
| Core architecture | Harpertown cores on 45 nm |
| Clocks | 2.5 GHz (no turbo) |
| Cache | 12 MB L2 (2x6 MB) |
| Processor base power (TDP) | 80 W |
| Manufacturing process | 45 nm |
| Memory support | DDR2 FB-DIMMs through the server board chipset |
| Front side bus | 1333 MT/s |
| PCI Express | PCIe from the board chipset |
| Integrated graphics | None |
| Multiplier | Locked |
| Package | LGA 771 |
Motherboard and chipset compatibility
Intel Xeon E5420 needs a motherboard with a Socket 771 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| Intel 5400 series | 5400 | Works out of the box |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for Socket 771.
Socket 771 at a glance
| Type | LGA, 771 contacts |
|---|---|
| Package size | 37.5 × 37.5 mm |
| Introduced | May 2006 |
| Memory | DDR2 and DDR3 through the server board chipset |
| Cooler mounting holes | Board specific (server heatsink) |
What the Xeon E5420 is
The Intel Xeon E5420 is a 2.5 GHz server quad core from November 2007. It runs four Core cores at 2.5 GHz with no turbo, so 4 cores give 4 threads. Cache is 12 MB of L2 as two 6 MB dies on a 45 nm process. Power is rated at 80 W on Socket 771.
The E5420 served mainstream Harpertown servers on a 1333 MT/s bus with a 7.5x multiplier. It exists because buyers wanted a 2.5 GHz quad with the full 12 MB cache between the 2.333 GHz E5410 and the 2.667 GHz E5430.
Socket and motherboard compatibility
The E5420 fits dual-socket Socket 771 server boards with a BIOS that lists Harpertown quads. It suits mainstream racks qualified for 80 W quads. Check the server maker CPU list for the exact board and stepping. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.
Memory, PCIe and cooling
Memory is DDR2 FB-DIMMs through the server board chipset.
A 1333 MT/s front side bus ties the CPU to the server chipset. PCIe slots hang off the chipset.
Cooling uses vendor qualified server heatsinks for the 80 W envelope in racks with directed airflow.
Upgrade paths
On Socket 771 the upgrade is the Intel Xeon E5430 at 2.667 GHz with the same cache at 80 W, or the Intel Xeon E5410 at 2.333 GHz for a lower cost. Beyond Socket 771 a move to a newer Xeon platform needs new boards and memory.
Frequently asked questions
What socket does the Xeon E5420 use?
Socket 771, in dual-socket server boards with Harpertown support.
How many cores does the Xeon E5420 have?
Four cores and 4 threads at 2.5 GHz with 12 MB of L2 cache.
What memory works with the Xeon E5420?
DDR2 FB-DIMMs through the server board chipset.
Sources and verification
Facts last checked against these sources on . Page last edited on .