Last week Intel introduced its highly anticipated Lynnfield processors under the Core i5 and Core i7 brands. Three chips emerged:
| Processor | Clock Speed | Cores / Threads | Maximum Single Core Turbo Frequency | TDP | Price |
| Intel Core i7-975 Extreme | 3.33GHz | 4 / 8 | 3.60GHz | 130W | $999 |
| Intel Core i7 965 Extreme | 3.20GHz | 4 / 8 | 3.46GHz | 130W | $999 |
| Intel Core i7 940 | 2.93GHz | 4 / 8 | 3.20GHz | 130W | $562 |
| Intel Core i7 920 | 2.66GHz | 4 / 8 | 2.93GHz | 130W | $284 |
| Intel Core i7 870 | 2.93GHz | 4 / 8 | 3.60GHz | 95W | $562 |
| Intel Core i7 860 | 2.80GHz | 4 / 8 | 3.46GHz | 95W | $284 |
| Intel Core i5 750 | 2.66GHz | 4 / 4 | 3.20GHz | 95W | $196 |
We tested exclusively with the Core i7 870 and the Core i5 750, the 860 didn't arrive in my lab until after the review went live. I was spending the greater part of a week with AMD at that time and didn't get to testing until this past weekend. Here's the chip:
What makes the Core i7 860 so interesting is that it's priced on par with everybody's favorite Nehalem: the Core i7 920. The 870 has great turbo modes, but it's nearly twice the price of the 860. The Core i5 750 wins in the price department, but it lacks Hyper Threading - part of what makes Nehalem so tasty in the first place. The 860 effectively gives us the best of both worlds, hence the focus on it for today's review.
I had a few mistakes in my original version of this table, but below you can see the turbo modes offered by the 860. They're not quite as nice as the 870, but the chip is also half as expensive. You'll also see that like the 750 you only get a single bin improvement with 3 or 4 cores active, but like the 870 you get 4 and 5 extra speed bins in the dual and single active core situations:
| Max Speed | Stock | 4 Cores Active | 3 Cores Active | 2 Cores Active | 1 Core Active |
| Intel Core i7 870 | 2.93GHz | 3.20GHz | 3.20GHz | 3.46GHz | 3.60GHz |
| Intel Core i7 860 | 2.80GHz | 2.93GHz | 2.93GHz | 3.33GHz | 3.46GHz |
| Intel Core i5 750 | 2.66GHz | 2.80GHz | 2.80GHz | 3.20GHz | 3.20GHz |
I've explained turbo mode in great detail here. In short, Lynnfield's PCU (Power Control Unit) looks at the number of cores active, shuts down those that are inactive, and uses the thermal savings to boost the clock speed of the active cores - all within the operating specs of the processor. Unless you're overclocking, turbo will never compromise system stability in search of greater performance.
| Single Core | Dual Core | Quad Core | Hex Core | |
| TDP |  |  |  |  |
 |  |  |  |
It works very well in practice, particularly with Windows 7. A question that's come up since the initial review is what happens when background tasks kick in. As I mentioned in the "Speed Limits" section of the Lynnfield review, this is something that can prevent turbo from kicking in:
"There's also the issue of background threads running in the OS. Although your foreground app may only use a single thread, there are usually dozens (if not hundreds) of active threads on your system at any time. Just a few of those being scheduled on sleeping cores will wake them up and limit your max turbo frequency (Windows 7 is allegedly better at not doing this)."
One of the features of Windows 7 is that the OS supposedly does a better job of grouping tasks together on a single core to avoid waking up an adjacent core and negating the gains from turbo mode. I'm still working on finding a good way to measure this but from what I've seen initially, Windows 7 tends to do a good job of grouping threads onto one or two cores - meaning we tend to see the 4-bin or 5-bin turbo modes. The other thing to keep in mind is that the processor can turbo up/down faster than the OS can schedule threads, the benefits of turbo are present even while in the middle of executing a task. Remember what dictates turbo is both thermal dissipation and current consumption; the mix of instructions executed varies depending on the task and even during the task, which in turn varies the frequency your core(s) will run at.
The end result is a system that seems to feel more responsive as well as perform better. Of course none of this matters if you're going to be disabling turbo and just overclocking, but I've addressed that scenario in a separate article today :)
And I don't really have a reason for showing this, but I like tables so here's the current quad-core processor landscape:
| Processor | Manufacturing Process | Die Size | Transistor Count | Socket |
| AMD Athlon II X4 | 45nm | 169 mm2 | 300M | AM2+/AM3 |
| AMD Phenom II X4 | 45nm | 258 mm2 | 758M | AM2+/AM3 |
| Intel Core i7 (Bloomfield) | 45nm | 263 mm2 | 731M | LGA-1366 |
| Intel Core i5/i7 (Lynnfield) | 45nm | 296 mm2 | 774M | LGA-1156 |
| Intel Core 2 Quad Q8xxx | 45nm | 164 mm2 | 456M | LGA-775 |
The Test
| Motherboard: | Intel DX58SO (Intel X58) Intel DP55KG (Intel P55) Intel DX48BT2 (Intel X48) Gigabyte GA-MA790FX-UD5P (AMD 790FX) |
| Chipset: | Intel X48 Intel P55 Intel X58 AMD 790FX |
| Chipset Drivers: | Intel 9.1.1.1015 (Intel) AMD Catalyst 8.12 |
| Hard Disk: | Intel X25-M SSD (80GB) |
| Memory: | Qimonda DDR3-1066 4 x 1GB (7-7-7-20) Corsair DDR3-1333 4 x 1GB (7-7-7-20) Patriot Viper DDR3-1333 2 x 2GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 280 |
| Video Drivers: | NVIDIA ForceWare 180.43 (Vista64) NVIDIA ForceWare 178.24 (Vista32) |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows Vista Ultimate 32-bit (for SYSMark) Windows Vista Ultimate 64-bit |
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Griswold - Saturday, September 19, 2009 - link
Well, you didnt go away either...coolkev99 - Monday, September 21, 2009 - link
In the zorro's world, processors can only be a fixed speed. Since Intel's newest dynamically changes he thinks it's somehow cheating.I wonder if the zorro thinks mobile CPU power saving features are cheating when they throttle down to save energy?
Just because a CPU can now change thier speed based on needs does not mean it's cheating. Better get used to it as this is the future of multicore CPUs.
vol7ron - Saturday, September 19, 2009 - link
You already made a similar comment in the other article. It's not overclocked, you're a moron. It's the same as saying that it underclocks as it uses more cores. That's the stock speed, which varies. Overclocking occurs when users modify the speeds beyond the specifications.Get over yourself AMD fanboi.
Nich0 - Saturday, September 19, 2009 - link
I don't be too much of a PITA, but surely the 'real' overclocking frequencies for the 860 should be of the 21*BCLK variety, no? Because it's stock rated speed is 21*133, its overclocked-at-stock-voltage-with-turbo speed should be 21*150 instead of 22*150. Looks to me as there's some kind of turbo going on on the CPUZ screenshots. Or am I missing something?iwodo - Saturday, September 19, 2009 - link
It is hardly surprising they are not selling well.Because, Nehalem didn't make as Big Jump as C2D in performance.
It is expensive, not only the chip itself. But the platform. Pentium 4 to C2D doesn't require new memory. And in some cases doesn't require new Motherboard as well.
Athlon Quad Core is Cheap. Consumers cares about Cores, not threads.
Economy doesn't allow to spend money upgrading on what is already working perfectly.
SSD offer much better value for money in terms of upgrade and investment.
No Integrated Graphics for Nehalem yet. ( Money need to spend on Graphics. )
Personally i am waiting for Sandy Bridge ( or even Ivy Bridge for FMA )
zero2dash - Tuesday, September 22, 2009 - link
It doesn't?My socket 478 P4 3.0C would like to disagree with you, considering that it used DDR ram. Practically all of the later P4's were s775, using DDR2 boards.
I wanted to upgrade - I bought a new board and new ram to go along with it.
zero2dash - Tuesday, September 22, 2009 - link
Ack, frickin' quote didn't work.[quote]Pentium 4 to C2D doesn't require new memory.[/quote]
afkrotch - Tuesday, September 22, 2009 - link
The move from P4 to C2D can be huge or small.1. new proc
2. new mobo
3. new memory
4. new gpu
5. new psu
You were required to pick up 1-5 new parts. When I upgraded, I needed all 5.
Stating about saving money, then saying an SSD offers much better value for money in terms of upgrade and investment. WTF. As of right now, it's probably the worst choice, unless you already have the best parts available.
Dobs - Sunday, September 20, 2009 - link
I think P55 may be the problem - without USB 3.0, PCIe 3.0 SATA 6gbsIf all were included it would be a must have - even 1 of the 3 would make it very tempting.
Perhaps they could release them like "Draft n"... That may get sales moving.
Griswold - Saturday, September 19, 2009 - link
I'm not so sure this is fact. Other rumors say, Intel aims for 1 million shipped chips by the end of 2009. Thats not exactly shabby, bad or "not so good". Intel, historically, has a pretty good grasp of what is possible due to their very close ties with their partners.http://www.digitimes.com/news/a20090916PD219.html">http://www.digitimes.com/news/a20090916PD219.html
Then again, this could also be just a rumor without much truth to it. We'll have to see whos right.
But I already know that you're right with some of what you said. I was not impressed with i7 (LGA1366). I was waiting for i5/i7 (LGA1156). And while I think it can be a good product for a relatively fair price (depending on which model you take), I cant justify ditching my Q6600 for it just yet. The best reason would be power consumption and turbo.
Instead, I went with a SSD and got more improvement out of that than any other upgrade could possibly deliver.
The 32nm parts may be interesting again. If not, I'll just wait for sandy bridge. Or maybe even AMDs bulldozer. My current system will take me there easily...