| 第18页： DDR2内存不同频率、时序对系统性能的影响：Pentium 4 Extreme Edition 3.73GHz |
NetBrust架构的Pentium 4 Extreme Edition
3.73GHz为单核心处理器，Prescott核心，1066MHz FSB，2MB L2
Cache，按照纸面理论，双通道的DDR2-533内存即能够满足这种处理器的内存带宽需求，即8.5GB/s，然而实际测试显示更高规格的内存仍然能够带来系统性能提升。
|
Pentium 4 Extreme Edition 3.73GHz on P5WD2-E Premium with Dual Channel
Memory |
DDR2-800@4-4-4-12 |
DDR2-667@4-4-4-12 |
|
EVEREST |
|
|
| Memory Read |
8277 MB/s |
8065 MB/s |
| Memory Write |
5637 MB/s |
5620 MB/s |
| Memory Copy |
5995 MB/s |
5500 MB/s |
| Memory Latency |
73.4 ns |
79.9 ns |
|
PCmark05 |
|
|
| Score |
5515 |
5468 |
| CPU |
4752 |
4698 |
| Memory |
4958 |
4848 |
|
Sandra |
|
|
| Memory Bandwidth
Benchmark Memory Int ALU Buffered |
6632 MB/s |
6415 MB/s |
| Memory Bandwidth
Benchmark Memory Float FPU Buffered |
6627 MB/s |
6439 MB/s |
| Memory Bandwidth
Benchmark Memory Int ALU Unbuffered |
4139 MB/s |
3702 MB/s |
| Memory Bandwidth
Benchmark Memory Float FPU Unbuffered |
4165 MB/s |
3731 MB/s |
|
SuperPI |
|
|
| 8M |
6'16" |
6'22" |
|
RazorLame with Lame |
|
|
| elapsed time |
1'54" |
1'56" |
|
Xmpeg with DivX Pro |
|
|
| elapsed time |
10'19" |
10'24" |
|
WinRAR |
|
|
| elapsed time |
15'01" |
15'54" |
|
3Dmark06 |
|
|
| 1280*1024*32bit
Overall |
5473 |
5468 |
| CPU score |
1150 |
1147 |
|
DOOM3 |
|
|
| 1280*1024*32bit |
111.8 fps |
109.3 fps |
| Half-life2 |
|
|
| 1280*1024*32bit |
138.5 fps |
134.3 fps |
使用相同时序设定4-4-4-12的DDR2-800和DDR2-667做性能对比，DDR2-800系统在内存带宽测试中大约有5%至10%的优势，在各类真实应用中，更高频率的内存系统带来的性能提升不到3%，只有WinRAR文件压缩表现得较为敏感，这在后面的多个测试中也有体现。
|
Pentium 4 Extreme Edition 3.73GHz on P5WD2-E Premium with Dual Channel
Memory |
DDR2-800@3-3-3-8 |
DDR2-800@4-4-4-12 |
DDR2-800@5-5-5-15 |
|
EVEREST |
|
|
|
| Memory Read |
8304 MB/s |
8277 MB/s |
8200 MB/s |
| Memory Write |
5643 MB/s |
5637 MB/s |
5634 MB/s |
| Memory Copy |
6175 MB/s |
5995 MB/s |
5888 MB/s |
| Memory Latency |
69.3 ns |
73.4 ns |
75.9 ns |
|
PCmark05 |
|
|
|
| Score |
5608 |
5515 |
5489 |
| CPU |
4753 |
4752 |
4719 |
| Memory |
5023 |
4958 |
4913 |
|
Sandra |
|
|
|
| Memory Bandwidth
Benchmark Memory Int ALU Buffered |
6730 MB/s |
6632 MB/s |
6530 MB/s |
| Memory Bandwidth
Benchmark Memory Float FPU Buffered |
6730 MB/s |
6627 MB/s |
6533 MB/s |
| Memory Bandwidth
Benchmark Memory Int ALU Unbuffered |
4400 MB/s |
4139 MB/s |
3856 MB/s |
| Memory Bandwidth
Benchmark Memory Float FPU Unbuffered |
4447 MB/s |
4165 MB/s |
3875 MB/s |
|
SuperPI |
|
|
|
| 8M |
6'12" |
6'16" |
6'20" |
|
RazorLame with Lame |
|
|
|
| elapsed time |
1'54" |
1'54" |
1'54" |
|
Xmpeg with DivX Pro |
|
|
|
| elapsed time |
10'15" |
10'19" |
10'20" |
|
WinRAR |
|
|
|
| elapsed time |
14'25" |
15'01" |
15'32" |
|
3Dmark06 |
|
|
|
| 1280*1024*32bit
Overall |
5480 |
5473 |
5470 |
| CPU score |
1150 |
1150 |
1150 |
|
DOOM3 |
|
|
|
| 1280*1024*32bit |
113.2 fps |
111.8 fps |
111.0 fps |
| Half-life2 |
|
|
|
| 1280*1024*32bit |
140.8 fps |
138.5 fps |
135.2 fps |
在相同DDR2频率而不同档次的三个时序设定下，各档次系统性能差距也并不明显，优化一档时序设定带来5%之内的带宽优势，真实应用能够获得2%不到的加速，WinRAR部分接近内存带宽提升比例，而音频压缩和3D
GAME则相对提升较弱。
