Intel Pentium III Xeon 866 2.8V socket: Slot 2
The Intel Pentium III Xeon 866 2.8V uses the Slot 2 slot. It is a 29.6 W single-core Cascades server part at 866 MHz with 256 KB of full-speed L2 cache for Slot 2 boards with 2.8 V regulation.
- Socket
- Slot 2
- Launched
- April 10, 2000
- Cores and threads
- 1 and 1
- Base power
- 29.6 W
- Codename
- Cascades
- Segment
- Server
- Family
- Intel Pentium III Xeon
- Clocks
- 0.87 GHz
Intel Pentium III Xeon 866 2.8V specifications
| Cores | 1 |
|---|---|
| Threads | 1 |
| Core architecture | Cascades (P6) |
| Clocks | 866 MHz base, no turbo |
| Cache | 32 KB L1, 256 KB full-speed L2 |
| Processor base power (TDP) | 29.6 W |
| Manufacturing process | 180 nm |
| Memory support | Registered ECC SDRAM through the server chipset |
| Front side bus | 133 MT/s |
| Package | Slot 2 (SECC cartridge, 330 contacts) |
| Multiplier | Locked (6.5x) |
| Integrated graphics | None |
Motherboard compatibility
Intel Pentium III Xeon 866 2.8V needs a motherboard with a Slot 2 socket. Chipset by chipset data for this codename is not recorded yet. See the Slot 2 chipset list and the board maker's CPU support list.
Slot 2 at a glance
| Type | Slot, 330 contacts |
|---|---|
| Package size | n/a |
| Introduced | April 1998 |
| Memory | Registered SDRAM through the board chipset |
| Cooler mounting holes | Cartridge and retention cage |
What the Pentium III Xeon 866 2.8V is
The Intel Pentium III Xeon 866 2.8V is an 866 MHz single-core server processor from April 2000. It runs one P6 Cascades core at 866 MHz with no Hyper-Threading, so 1 core gives 1 thread. Cache is 256 KB of full-speed L2 with 32 KB of L1 on a 180 nm process. Power is rated at 29.6 W in a Slot 2 SECC cartridge on a 133 MT/s front side bus with a 6.5x multiplier on the 2.8 V regulator path.
The 2.8 V string feeds the cartridge core directly while the 5V-12V string leans on board regulation, which is why server lines stock one or the other at matching clocks. Intel launched both 866 strings on April 10, 2000. The chip supports MMX, SSE and two-way SMP.
Matching clocks and cache with direct regulation suit Slot 2 servers built for the 2.8 V path. The SECC thermal plate carries the 29.6 W envelope. That is why the 2.8V string shipped in 2.8 V server lines.
Socket and motherboard compatibility
The 866 2.8V fits Slot 2 servers wired for 2.8 V Xeon regulation. It needs a 330-lead SC330 board with a 133 MT/s bus and a BIOS that lists the 2.8 V Xeon 866. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.
2.8 V rack servers are the natural match. Boards listing the 2.8 V string accept cartridges with 29.6 W heatsinks.
Memory, PCIe and cooling
Memory is registered ECC SDRAM through the server chipset, matched to the board sockets. The cartridge has no memory controller. Server boards commonly run ECC pairs.
A 133 MT/s front side bus ties each cartridge to the chipset, while PCI hangs off the chipset. No PCIe lanes originate on the cartridge. Cooling uses SECC heatsinks on the retention cage.
Upgrade paths
On the same slot, a move to a Pentium III Xeon 866 5V-12V such as Intel Pentium III Xeon 866 5V-12V keeps clocks and cache while changing regulator path. A Xeon 933 on the same list adds clocks at similar power.
A move to Foster Xeon needs Socket 603. The Slot 2 page lists the range for planning.
Frequently asked questions
What socket does the Pentium III Xeon 866 2.8V use?
Slot 2. It is a 29.6 W Cascades server part at 866 MHz in the 2.8 V variant.
What memory does the 866 2.8V use?
Registered ECC SDRAM through the server chipset.
What is the upgrade path from the 866 2.8V?
An 866 5V-12V on boards wired for that regulator.
Sources and verification
- List of Intel Xeon processors P6-based 866 (Wikipedia)
- Pentium III Xeon 733 5V-12V family ref (TechPowerUp)
- Slot 2 (Wikipedia)
Facts last checked against these sources on . Page last edited on .