Intel Sandy Bridge

Intel Sandy Bridge

Configuration

Intel i5-2400 (Sandy Bridge), 3.1 GHz, 32 nm.

• L1 Data cache = 32 KB. 64 B/line, 8-WAY. (Write-Allocate?), 2 * 16 Bytes read ports + 16 Bytes store port.
• L1 Instruction cache = 32 KB. 8-WAY. 64 B/line
• mOp Cache: 1.5k instructions, 8-WAY, 6 MOP / line
• 4 decoders, 16 bytes per cycle
• L2 cache = 256 KB. 64 B/line, 8-WAY
• L3 cache = 6 MB. 64 B/line, 12-WAY
• Load Buffers = 64
• Store Buffers = 36
• Line fill buffers (LFB) = 10
• RS = 54 items
• PRF Integer = 160 registers
• PRF Float = 144 registers
• ROB = 168 items
• RSB (return stack buffer) = 16 items ?

4 KB pages mode (64-bit Windows)

• Data TLB L1 size = 64 items. Miss penalty = 7. 4- WAY
• Instruction TLB L1 size = 64 items per thread.
• TLB L2 size = 512 items. . 4- WAY
• PDE cache = 32 items?

Size	Latency	Description
32 K	4 | 5	TLB + L1
256 K	12	+7 (L2)
2 M	36	+17 (L3) +7 (L1 TLB miss)
6 M	46	+10 (L2 TLB miss)
64 M	46 + 65 ns	+ 65 ns (RAM)
...	58 + 65 ns	+ 12 (PDE cache miss)

• L1 Latency = 4 cycles is for direct pointers mode. The [R1 + R2*4] Load has 5 cycles latency.
• L3 Latency for cores 2 and 3 is 1-cycle smaller than L3 Latency for cores 1 and 4.

2 MB pages mode (64-bit Windows, 64-bit soft)

• Data TLB L1 size = 32 items.
• Data TLB L2 size = 512 items.
• Instruction TLB L1 = ? items

1 GB mode

• Data TLB L1 size = 4 items.
• Data TLB L2 size = 512 items.
• Instruction TLB L1 = ? items

MISC

Branch misprediction penalty = 14 cycles.

• 64-bytes range cross penalty = 5 cycles
• 4096-bytes range cross penalty = 24 cycles
• L1 B/W (Parallel Random Read) = 0.51 cycles per one access
• L2->L1 B/W (Parallel Random Read) = 2.5 cycles per cache line
• L2->L1 B/W (Read, 64 bytes step) = 2.1 cycles per cache line
• L2 Write (Write, 64 bytes step) = 6.70 cycles per write (cache line)
• L3->L1 B/W (Parallel Random Read) = 4.85 cycles per cache line
• L3->L1 B/W (Read, 64 bytes step) = 5.05 cycles per cache line
• L3 Write (Write, 64 bytes step) = 9.00 cycles per write (cache line)
• RAM Read B/W (Parallel Random Read) = 10 ns / cache line = 6400 MB/s
• RAM Read B/W (Read, 8 Bytes step) = 13700 MB/s
• RAM Read B/W (Read, 64 Bytes step) = 15200 MB/s
• RAM Read B/W (Read, 64 Bytes step - pointer chasing) = 11700 MB/s
• RAM Write B/W (Write, 4-64 Bytes step) = 9200 MB/s

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