How The Cache Memory Works
Memory Cache Configuration on Current CPUs
Contents
Below we present you a reference table containing the main memory cache specs for the main CPUs available on the market today.
| CPU | L1 Instruction | L1 Data | L2 |
| Athlon 64 | 64 KB 2-way set associative 64-byte lines 128-bit datapath with L2 128-bit datapath with fetch unit |
64 KB 2-way set associative 64-byte lines 128-bit datapath with L2 |
512 KB or 1 MB 16-way set associative 64-byte lines 128-bit datapath with L1 data 128-bit datapath with L1 instruction |
| Athlon 64 FX | 64 KB per core 2-way set associative 64-byte lines 128-bit datapath with L2 128-bit datapath with fetch unit |
64 KB per core 2-way set associative 64-byte lines 128-bit datapath with L2 |
1 MB per core 16-way set associative 64-byte lines 128-bit datapath with L1 data 128-bit datapath with L1 instruction |
| Athlon 64 X2 | 64 KB per core 2-way set associative 64-byte lines 128-bit datapath with L2 128-bit datapath with fetch unit |
64 KB per core 2-way set associative 64-byte lines 128-bit datapath with L2 |
512 KB or 1 MB per core 16-way set associative 64-byte lines 128-bit datapath with L1 data 128-bit datapath with L1 instruction |
| Sempron (sockets 754 and AM2) | 64 KB 2-way set associative 64-byte lines 128-bit datapath with L2 128-bit datapath with fetch unit |
64 KB 2-way set associative 64-byte lines 128-bit datapath with L2 |
128 KB or 256 KB 16-way set associative 64-byte lines 128-bit datapath with L1 data 128-bit datapath with L1 instruction |
| Opteron | 64 KB per core 2-way set associative 128-bit datapath with L2 128-bit datapath with fetch unit |
64 KB per core 2-way set associative 64-byte lines 128-bit datapath with L2 |
1 MB per core 16-way set associative 64-byte lines 128-bit datapath with L1 data 128-bit datapath with L1 instruction |
| Pentium 4 | N/A * | 8 KB 4-way set associative 64-byte lines 256-bit datapath with L2 |
256 KB, 512 MB or 1 MB 8-way set associative 128-byte lines 64-bit datapath with fetch unit 256-bit datapath with L1 data |
| Pentium D | N/A * | 16 KB 4-way set associative 64-byte lines 256-bit datapath with L2 |
1 MB or 2 MB per core 8-way set associative 128-byte lines 64-bit datapath with fetch unit 256-bit datapath with L1 data |
| Core 2 Duo | 32 KB 64-byte lines 256-bit datapath with fetch unit |
32 KB 64-byte lines 256-bit datapath with L2 |
2 MB or 4 MB 8-way set associative 64-byte lines 256-bit datapath with L1 data |
| Pentium Dual Core | 32 KB 64-byte lines 256-bit datapath with fetch unit |
32 KB 64-byte lines 256-bit datapath with L2 |
1 MB 8-way set associative 64-byte lines 256-bit datapath with L1 data |
* There is a 150 KB trace cache on these processors. This cache is located between the decoder unit and the execution unit. Thus the fetch unit grabs data directly from L2 memory cache.
We didn’t include Xeon and Celeron processors on the above table because there are several different Xeon and Celeron models around based on different architectures. Celeron and Xeon based on Netburst microarchitecture (i.e., based on Pentium 4) will have the same specs as Pentium 4 but with different L2 cache size, while Celeron and Xeon based on Core microarchitecture (i.e., based on Core 2 Duo) will have the same specs as Core 2 Duo but with different L2 cache size.