The Intel Core i7 860 Review

by Anand Lal Shimpi on September 18, 2009 12:00 AM EST

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


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
Chipset Drivers: Intel (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
SYSMark 2007 Performance
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  • iwodo - Sunday, September 20, 2009 - link

    Well, it will defiantly sell well in terms of OEM market. Since they will sell the same amount of PC, and Intel will be pushing Lynfield into their throat anyway.

    I wont even called that Sales, it is more like tax on those OEM makers.

    I think it wont sell well in terms of Retail market.
  • IntelUser2000 - Saturday, September 19, 2009 - link

    Ivy Bridge is a shrink of Sandy Bridge to 22nm. It's Haswell that will have FMA.
  • iwodo - Sunday, September 20, 2009 - link

    Yes. It is Ivy Beidge ( the shrink of Sandy Bridge ) for FMA.
    It was supposed to be for Sandy Bridge, but some changes delay it to Ivy Bridge. So unless they have postponed it AGAIN. it should be out with Ivy Bridge.
  • bigboxes - Saturday, September 19, 2009 - link

    I know the basic archetecture of Lynnfield is superior to Bloomfield, but you are not using 6gb of tri-channel memory for the i920. That is where the i920 really shines. Is there a reason that you are not testing with 6gb of ram with the 920 other than apples to apples testing that needs to be done? Just curious.
  • the zorro - Saturday, September 19, 2009 - link

    lynnfield has another gigantic bottleneck which is the dmi bus speed of only 2GBps, phenom 2 hypertransport speed is 41.6 GB/s which means that is 20 times faster than lynnfield when communicating with the chipset,that shows why phenom 2 is better than lynnfield. this is going to be a real problem in the next future.
  • silverblue - Saturday, September 19, 2009 - link

    Actually, as HT 3.0 is limited to 16-bit width on AMD desktop boards, it's half that.
  • DigitalFreak - Saturday, September 19, 2009 - link

    Next future? As opposed to the current future? I must thank you for all the laughs I get from reading your posts.
  • TA152H - Saturday, September 19, 2009 - link

    No offense, but you're clearly an idiot.

    You realize that in EVERY benchmark, the i7 860 was running at higher clock speeds than the i7 920. Sometimes by a lot, with turbo mode. Also, Anand uses inferior memory for the i7 920, to try to 'prove' the validity of the brain-damaged P55 platform.

    Despite his bad attempt, the i7 920 STILL outperformed it. If you clock them at the same rate, with the same uncore, it's only ugly for the Lynnfield.

    It's not superior. Well, in performance. It's got nice power characteristics, and it's cheaper to implement. But, your remark is purely idiotic.

    Where do you get stuff like this from?
  • Etern205 - Sunday, September 20, 2009 - link

    Lynnfields are categorizes as mainstream, therefore no matter how advanced their architecture is compared to Bloomfield, it won't out perform it. Intel purposely did this and you should know this by now, but I guess you don't care as your too busy sucking your own c0ck.

    "Your the kind of man that can be use as a blueprint to build a idiot".

  • bigboxes - Sunday, September 20, 2009 - link

    Sorry. I didn't mean to say anything that would warrant an "idiot" label. I have just been reading from Anand that the Lynnfield core is better than the Bloomfield. In all his testing he never uses 6gb of ram in his tests. I understand that he wants to measure the cpus on a level playing field, but when you put 6gb of pc1600 ram on an i920 those scores increase considerably. From what I understand that is something that the Lynnfield cannot achieve. Was just wondering if Anand could throw that (i920 w/6gb) into his charts. It seems that almost all Bloomfield owners are gonna be running 6gb (3x 2gb) and not 4gb. The i920 uses that extra bandwidth and it truly performs better when so equipped. I hope that makes more sense.

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