Athlon II X4 645

Details and Benchmarks for AMD Athlon II X4 645

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Benchmark Results

Combined benchmark scores based on multiple data points, giving a quick overview of this processor's performance.

Overall Score

Overall score for Athlon II X4 645 based on all benchmark results gathered. Look at this like a meta score, you will find more specific workload ratings below.

4,351 Rank: 1469
Rank Name Score Visual
1465 Core i3-550 4,355
+0.1%
1466 Pentium 4 3.80GHz 4,354
+0.1%
1467 FX-6100 4,352
+0%
1468 Phenom II X4 940 4,352
+0%
1469 Athlon II X4 645 4,351
1470 Core i3-6006U 4,350
+-0%
1471 A6-7400K 4,350
+-0%
1472 Core i5-580M 4,349
+-0%
1473 Phenom II X3 B77 4,349
+-0%
1474 Pentium E6800 4,345
-0.1%

View full ranking →

Multicore Score

Multicore performance score for Athlon II X4 645 based on multi-threaded benchmark results.

4,464 Rank: 1295
Rank Name Score Visual
1291 Core i7-940 4,466
+0%
1292 Athlon 200GE 4,465
+0%
1293 Core i7-6500U 4,464
+0%
1294 Celeron G3930TE 4,464
+0%
1295 Athlon II X4 645 4,464
1296 Phenom II X4 925 4,463
+-0%
1297 Phenom 9550 4,463
+-0%
1298 Xeon X5450 4,462
+-0%
1299 A8-7670K 4,461
-0.1%
1300 FX-4100 4,461
-0.1%

View full ranking →

Singlecore Score

Single-core performance score for Athlon II X4 645 based on single-threaded benchmark results.

4,276 Rank: 1510
Rank Name Score Visual
1506 FX-6100 4,280
+0.1%
1507 Pentium E6500 4,279
+0.1%
1508 Core 2 Quad Q9400 4,279
+0.1%
1509 Core i7-860S 4,278
+0%
1510 Athlon II X4 645 4,276
1511 Xeon W3505 4,276
+0%
1512 Core i5-560M 4,275
+-0%
1513 A6-5357M 4,273
-0.1%
1514 Core 2 Quad Q8400 4,271
-0.1%
1515 A10-9620P 4,270
-0.1%

View full ranking →

Workload Scores

Performance scores grouped by workload type, normalized and aggregated from multiple raw benchmark results.

Number Crunching

Aggregated score for Athlon II X4 645 based on integer math, floating point math, and prime number computation benchmarks.

4,524 Rank: 1350
Rank Name Score Visual
1346 Core i5-3427U 4,525
+0%
1347 A8-3820 4,525
+0%
1348 Phenom II X4 900e 4,525
+0%
1349 Phenom II X4 820 4,525
+0%
1350 Athlon II X4 645 4,524
1351 Pentium 5405U 4,524
+0%
1352 Pentium 4417U 4,524
+0%
1353 Pentium 4415U 4,524
+0%
1354 Core i3-3120M 4,524
+0%
1355 Core M-5Y70 4,524
+0%

View full ranking →

Data Processing

Aggregated score for Athlon II X4 645 based on data encryption, data compression, and string sorting benchmarks.

4,539 Rank: 1112
Rank Name Score Visual
1108 Core i5-7300U 4,539
+0%
1109 A10-6700 4,539
+0%
1110 A8-9600 4,539
+0%
1111 A10-9700E 4,539
+0%
1112 Athlon II X4 645 4,539
1113 Xeon E5450 4,539
+0%
1114 Core i5-L16G7 4,539
+0%
1115 Core i7-7500U 4,538
+-0%
1116 A8-6600K 4,538
+-0%
1117 A10-7860K 4,538
+-0%

View full ranking →

Physics & Compute

Aggregated score for Athlon II X4 645 based on physics simulation and extended instruction set (SSE/AVX) benchmarks.

4,504 Rank: 1378
Rank Name Score Visual
1374 Phenom II X4 B40 4,505
+0%
1375 Phenom II X4 830 4,505
+0%
1376 A10-4600M 4,505
+0%
1377 Core i5-650 4,505
+0%
1378 Athlon II X4 645 4,504
1379 Pentium G2030 4,504
+0%
1380 Celeron G1840 4,504
+0%
1381 Pentium G2020 4,504
+0%
1382 Core M-5Y10 4,504
+0%
1383 A10-7400P 4,504
+0%

View full ranking →

Athlon II X4 645 Details

The AMD Athlon II X4 645, launched in September 2010, represents a mid-tier desktop processor from AMD's older Athlon II X4 lineup, built on the Propus microarchitecture and designed for Socket AM3 motherboards. While it was once a competitive option for budget-conscious users, the processor now stands as a relic in today’s computing landscape, having been outpaced by modern CPUs that deliver significantly higher performance and efficiency. As of March 2026, the Athlon II X4 645 is no longer relevant for mainstream use, especially when compared to today’s top-tier processors like the Ryzen Threadripper PRO 9995WX or Core Ultra 9 285K, which outperform it by orders of magnitude in both single-core and multicore workloads.

Despite its age, the Athlon II X4 645 was notable for its 4-core design, with each core equipped with 512 KB of L2 cache, totaling 2 MB. It operates at a base frequency of 3.1 GHz and includes a 15.5x clock multiplier, which is locked, limiting overclocking potential. The processor uses a 45 nm manufacturing process and contains 300 million transistors. It supports dual-channel DDR3 memory at speeds up to 1600 MHz, with a maximum memory capacity of 16 GB and a peak bandwidth of 25.6 GB/s. The chip is packaged in a µPGA socket with a TDP of 95 W, requiring substantial cooling due to its relatively high power consumption.

The Athlon II X4 645 lacks integrated graphics, relying instead on a discrete GPU or a motherboard chipset that supports discrete graphics. However, some systems with compatible chipsets can offer basic graphics functionality through shared memory. This limitation restricts its use in systems where integrated graphics are essential.

In benchmark testing, the Athlon II X4 645 achieves an overall score of 4351, ranking #1469 out of 2060 CPUs. Its single-core score of 4276 places it at #1510, while its multicore score of 4464 lands at #1293. These results show that the processor is competitive with older dual- and quad-core CPUs like the Core i5-3340M and Phenom II X4 925, but falls behind modern low-power and mobile processors such as the Core i3-6006U. The multicore performance is slightly stronger than its single-core performance, indicating that it benefits more from multi-threaded workloads, though it still trails far behind current-generation CPUs.

Despite its outdated architecture and performance, the Athlon II X4 645 holds historical significance as part of AMD’s push into affordable multi-core desktop computing. It supports a range of features including SSE, SSE2, SSE3, SSE4.1, SSE4.2, AVX2, AES-NI, and AMD-V, making it capable of running older operating systems and applications. However, its lack of modern technologies such as DDR4 support, PCIe 4.0, and advanced power management features renders it obsolete for today’s computing demands.

In conclusion, the Athlon II X4 645 is best suited for legacy systems, retro builds, or as a low-cost upgrade in environments where modern performance is not required. For users seeking modern efficiency, performance, or compatibility with current software, the processor is no longer viable. As of March 2026, it serves more as a nostalgic reminder of a bygone era in CPU design than as a practical choice for new builds.
Frequently Compared

Intel Core i9-7980XE 8 views

Intel Xeon Silver 4112 5 views

Intel Pentium Silver J5005 4 views

AMD Ryzen Threadripper 2950X 3 views

AMD Ryzen 9 PRO 3900 1 view

AMD Ryzen 5 PRO 3500U 1 view

AMD Ryzen 3 PRO 2200GE 1 view

Intel Xeon Silver 4214 1 view

Intel Xeon Silver 4116T 1 view

Intel Core i7-6650U 1 view

AMD Athlon II X4 645

Main Specifications

Designer: AMD
Name: Athlon II X4 645
Model Number: i5-5250U
Cores: 2
Threads: 4
Base Frequency: 1600 MHz
Clock Multiplier: 15.5xx (locked)
Core Name: Propus
Socket: FCBGA1168
Package: µPGA
Target Segment: Desktop
Max CPUs: 1
TDP: 15 W

Cache Specifications

L1 Cache: 124.928 KiB
L2 Cache: 0.488 MiB

Memory Specifications

Supported Memory Type: DDR3L 1333/1600, LPDDR3 1600/1866
Memory Channels: 2
Maximum Memory: 0 GB
Maximum Bandwidth: 25.6 GB/s
ECC Support: No

PCI-Express Specifications

PCIe Revision: 2.0
PCIe Lanes: 12
PCIe Configuration: 4x1, 2x4

Integrated Graphics

GPU: HD Graphics 6000
GPU Designer: Intel
GPU Max Frequency: 950 MHz

Physical Specifications

Process: 14 nm
Die Area: 169 mm²
Transistor Count: 0.00 billion
Word Size: 64-bit

CPU Features

MMX SSE SSE2 SSE3 SSE4.1 SSE4.2 AVX2 AES x86-64 HT EIST TXT vPro VT-x VT-d EPT Secure Key SMEP SIPP IPT SSE4a AMD-V TSX Flex Memory FMA 3DNow!
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