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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Gary Key - Monday, November 3, 2008 - link
"The 920 to 3.6/3.8 is a nice overclock but I wonder what you mean by proper cooling and how close you came to crossing the 80C "boundary"?"It was actually quite easy to do with the retail cooler, in fact in our multi-task test playing back a BD title while encoding a BD title, the core temps hit 98C. Cinebench multi-core test and OCCT both had the core temps hit 100C at various points. Our tests were in a closed case loaded out with a couple of HD4870 cards, two optical drives, three hard drives, and two case fans.
Proper cooling (something we will cover shortly) consisted of the Thermalright Xtreme120, Vigor Monsoon II, and Cooler Master V8 along with the Freezone Elite. We were able to keep temps under 70C with a full load on air and around 45C with the Freezone unit.
Th3Eagle - Tuesday, November 4, 2008 - link
Wow, thats interesting. Can't wait to see the new article. Always nice to see an article about coolers.Thanks for the reply.
Anand Lal Shimpi - Monday, November 3, 2008 - link
Gary did the i7-920 tests so I'll let him chime in there, we're also working on an overclocking guide that should help address some of these concerns.-A
whatthehey - Monday, November 3, 2008 - link
Tom's? You might as well reference HardOCP....Okay, THG sometimes gets things right, but I've seen far too many "expose" articles where they talk about the end of the world to take them seriously. Ever since the i820 chipset fiasco, they seem to think everything is a big deal that needs a whistle blower.
Anandtech got 3.8GHz with an i7-920, and I would assume due diligence in performance testing (i.e. it's not just POSTing, but actually running benchmarks and showing a performance improvement). I'm still running an overclocked Q6600, though, and the 3.6GHz I've hit is really far more than I need most of the time. I should probalby run at 3.0GHz and shave 50-100W from my power use instead. But it's winter now, and with snow outside it's nice to have a little space heater by my feet!
The0ne - Monday, November 3, 2008 - link
TomHardware and Anandtech were the one websites I visited 13 years ago during my college years. Tom's has since been pushed far down the list of "to visit sites" mainly due to their poor articles and their ad littered, poorly designed website. If you have any type of no-script enable there's quite a bit to enable to have the website working. The video commentary is a joke as they're not professionals to get the job done professionally...visually anyhow.Anandtech has stayed true to it's root and although I find some articles a bit confusing I don't mind them at all. Example of this are camera reviews :)
GaryJohnson - Monday, November 3, 2008 - link
Geez, calling a core 2 a space heater. How soon we forget prescott...JarredWalton - Monday, November 3, 2008 - link
I think overclocked Core 2 Quad is still very capable of rating as a space heater. The chips can easily use upwards of 150W when overclocked, which if memory serves is far more than any of the Prescott chips did. After all, we didn't see 1000W PSUs back in the Prescott era, and in fact I had a 350W PSU running a Pentium D 920 at 3.4 GHz without any trouble. :-)Griswold - Tuesday, November 4, 2008 - link
Funny comparison. If it was just for the space heater arguments sake (well, 150W is by far not enough to qualify as a real space heater to be honest), I could follow you but saying the 150W of a 4 core, more-IPC-than-any-P4-can-ever-dream-of, processor should or could be compared to the wattage of the infamous thermonuclear furnace AKA prescott, is a bit of a long stretch, dont you think? :pRyan Smith - Monday, November 3, 2008 - link
Intel can call it supercalifragilisticexpialidocious until they're blue in the face, but take it from a local, it's Neh-Hay-Lem. Just see how it's pronounced in this news segment:http://www.katu.com/outdoors/3902731.html?video=YH...">http://www.katu.com/outdoors/3902731.html?video=YH...
mjrpes3 - Monday, November 3, 2008 - link
Any chance we'll see some database/apache benchmarks based on Nehalem soon?