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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npp - Tuesday, November 4, 2008 - link
Well, the funny thing is THG got it all messed up, again - they posted a large "CRIPPLED OVERCKLOCKING" article yesterday, and today I saw a kind of apology from them - they seem to have overlooked a simple BIOS switch that prevents the load through the CPU from rising above 100A. Having a month to prepare the launch article, they didn't even bother to tweak the BIOS a bit. That's why I'm not taking their articles seriously, not because they are biased towards Intel ot AMD - they are simply not up to the standars (especially those here @anandtech).gvaley - Tuesday, November 4, 2008 - link
Now give us those 64-bit benchmarks. We already knew that Core i7 will be faster than Core 2, we even knew how much faster.Now, it was expected that 64-bit performance will be better on Core i7 that on Core 2. Is that true? Draw a parallel between the following:
Performance jump from 32- to 64-bit on Core 2
vs.
Performance jump from 32- to 64-bit on Core i7
vs.
Performance jump from 32- to 64-bit on Phenom
badboy4dee - Tuesday, November 4, 2008 - link
and what's those numbers on the charts there? Are they frames per second? high is better then if thats what they are. Charts need more detail or explanation to them dude!TSM
MarchTheMonth - Tuesday, November 4, 2008 - link
I don't believe I saw this anywhere else, but the spots for the cooler on the Mobo, they the same as like the LGA 775, i.e. can we use (non-Intel) coolers that exist now for the new socket?marc1000 - Tuesday, November 4, 2008 - link
no, the new socket is different. the holes are 80mm far from each other, on socket 775 it was 72mm away.Agitated - Tuesday, November 4, 2008 - link
Any info on whether these parts provide an improvement on virtualized workloads or maybe what the various vm companies have planned for optimizing their current software for nehalem?yyrkoon - Tuesday, November 4, 2008 - link
Either I am not reading things correctly, or the 130W TDP does not look promising for the end user such as myself that requires/wants a low powered high performance CPU.The future in my book is using less power, not more, and Intel does not right now seem to be going in this direction. To top things off, the performance increase does not seem to be enough to justify this power increase.
Being completely off grid(100% solar / wind power), there seem to be very few options . . . I would like to see this change. Right now as it stands, sticking with the older architecture seems to make more sense.
3DoubleD - Tuesday, November 4, 2008 - link
130W TDP isn't much worse for previous generations of quad core processors which were ~100W TDP. Also, TDP isn't a measure of power usage, but of the required thermal dissipation of a system to maintain an operating temperature below an set value (eg. Tjmax). So if Tjmax is lower for i7 processors than it is for past quad cores, it may use the same amount of power, but have a higher TDP requirement. The article indicates that power draw has increased, but usually with a large increase in performance. Page 9 of the article has determined that this chip has a greater performance/watt than its predecessors by a significant margin.If you are looking for something that is extremely low power, you shouldn't be looking at a quad core processor. Go buy a laptop (or an EeePC-type laptop with an Atom processor). Intel has kept true to its promise of 2% performance increase for every 1% power increase (eg. a higher performance per watt value).
Also, you would probably save more power overall if you just hibernate your computer when you aren't using it.
Comdrpopnfresh - Monday, November 3, 2008 - link
Do differing cores have access to another's L2? Is it directly, through QPI, or through L3?Also, is the L2 inclusive in the L3; does the L3 contain the L2 data?
xipo - Monday, November 3, 2008 - link
I know games are not the strong area of nehalem, but there are 2 games i'd like to see tested. Unreal T. 3 and Half Life 2 E2.. just to know how does nehalem handles those 2 engines ;D