The Dark Knight: Intel's Core i7
by Anand Lal Shimpi & Gary Key on November 3, 2008 12:00 AM EST- Posted in
- CPUs
What about the Impact of DDR3 Speeds?
Intel only officially supports up to DDR3-1066 on Nehalem, but hitting 1333MHz and 1600MHz isn't a problem thanks to DDR3 being a mature technology that's been in use for a couple of years now.
| Triple Channel DDR3-1066 (9-9-9-20) | Triple Channel DDR3-1333 (9-9-9-20) | Triple Channel DDR3-1600 (9-9-9-24) | |
| Memory Tests - Everest v1547 | |||
| Read Bandwidth | 13423 MB/s | 14127 MB/s | 17374 MB/s |
| Write Bandwidth | 12401 MB/s | 12404 MB/s | 14169 MB/s |
| Copy Bandwidth | 18074 MB/s | 16953 MB/s | 19447 MB/s |
| Latency | 44.2 ns | 38.8 ns | 33.5 ns |
| x264 HD Encoding Test (First Pass / Second Pass) | 85.3 fps / 30.3 fps | 86.4 fps / 30.6 fps | 88.1 fps / 30.7 fps |
| WinRAR 3.80 - 602MB Folder | 117 seconds | 111 seconds | 106 seconds |
| PCMark Vantage | 7490 | 7569 | 8102 |
| Vantage - Memories | 6712 | 6809 | 6886 |
| Vantage - TV and Movies | 5637 | 5716 | 5716 |
| Vantage - Gaming | 9849 | 10570 | 11013 |
| Vantage - Music | 4593 | 4798 | 4896 |
| Vantage - Communications | 6422 | 6486 | 6630 |
| Vantage - Productivity | 7676 | 7803 | 7819 |
| WinRAR (Built in Benchmark) | 3306 | 3520 | 3707 |
| Nero Recode - Office Space - 7.55GB | 130 seconds | 127 seconds | 126 seconds |
| SuperPI - 32M (mins:seconds) | 11:52 | 11:36 | 11:25 |
| Far Cry 2 - Ranch Medium (1680 x 1050) | 62.4 fps | 62.5 fps | 62.7 fps |
| Age of Conan - 1680 x 1050 | 51.1 fps | 51.1 fps | 51.1 fps |
| Company of Heroes - 1680 x 1050 | 133.6 fps | 135.8 fps | 136.8 fps |
The real world performance benefit from going to DDR3-1066 to 1600, despite having to lower memory timings slightly, is around 3%. The raw increase in memory bandwidth amounts to about 30% and in a completely memory bandwidth bound test like the WinRAR benchmark you're looking at a 12% boost in performance, but that's going to be very rare in most real world scenarios. The reduction in latency is particularly impressive when you jump up to DDR3-1600, it only takes 33.5ns to access main memory.
If you do want the absolute best performance out of your Nehalem system you're going to want a three-channel DDR3-1600+ kit, but you'll only be giving up a couple of percent if you opt for the entry level 1066MHz modules at like timings. Although not shown, in this article anyway, reducing the memory timings to 7-7-7-20 at DDR3-1066 will close the slight performance gap quickly in most instances.
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fzkl - Monday, November 3, 2008 - link
"Where Nehalem really succeeds however is in anything involving video encoding or 3D rendering"We have new CPU that does Video encoding and 3D Rendering really well while at the same time the GPU manufacturers are offloading these applications to the GPU.
The CPU Vs GPU debate heats up more.
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Griswold - Tuesday, November 4, 2008 - link
Wheres the product that offloads encoding to GPUs - all of them, from both makers - as a publicly available product? I havent seen that yet. Of course, we havent seen Core i7 in the wild yet either, but I bet it will be many moons before there is that single encoding suite that is ready for primetime regardless of the card that is sitting in your machine. On the other hand, I can encode my stuff right now with my current Intel or AMD products and will just move them over to the upcoming products without having to think about it.Huge difference. The debate isnt really a debate yet, if you're doing more than just talking about it.
haukionkannel - Monday, November 3, 2008 - link
Well if both CPU and GPU are better for video encoding, the better! Even now the rendering takes forever.So there is not any problem if GPU helps allready good 3d render CPU. Everything that gives more speed is just bonus!