Intel's Core i7 870 & i5 750, Lynnfield: Harder, Better, Faster Stronger
by Anand Lal Shimpi on September 8, 2009 12:00 AM EST- Posted in
- CPUs
Final Words
I'll start this conclusion with what AMD must do in response to Lynnfield. The Core i5 750 is a great processor at $196, in fact, it's the best quad-core CPU you can buy at that price today. In nearly every case it's faster than AMD's Phenom II X4 965 BE, despite the AMD processor costing almost another $50. Granted you can probably save some money on an integrated 785G motherboard, but if you're comparing ~$120 motherboards the AMD CPU is simply overpriced.
Lynnfield (top) vs. Phenom II (bottom)
Luckily, the solution isn't that difficult. AMD needs to lower prices. The problem is that AMD has too many products below $200 already. The Phenom II X3 and X4 series both exist below $200 and rumor has it that AMD is also going to introduce a quad-core Athlon II somewhere down there. Lynnfield's arrival causes a lot of price compression on AMD's side. The most AMD should sell the 965 BE for is $199, but if it is to remain competitive the chip needs to be priced much lower. That doesn't leave much room for other AMD CPUs. On the bright side, this could force AMD to simplify its product lines again (similar to what it has quietly been doing already).
The next thing that the Core i5 750 does is it finally ends the life of LGA-775. Just as was the case with AMD, the Core 2 Quad Q9650 is easily destroyed by the Core i5 750 and at a lower price. With significantly lower motherboard costs than the LGA-1366 chips, the Core i5 750 can actually compete in the high end LGA-775 space. It's only a matter of time before the sub-$200 LGA-775 parts are made obsolete as well.
Lynnfield power consumption is just excellent, these are the most power efficient quad-core CPUs we've ever tested. They use less power at idle than similarly clocked dual-core processors and under load they deliver better performance per watt than any of their closest competitors. Later this year we'll see 32nm dual-core Westmere start to ship for notebooks. I don't have performance data but I'd expect that early next year will be the perfect time to buy a new notebook.
Can you tell that I like the Core i5 750? Again, at $196 you can't find a better processor. Intel did its homework very well and managed to deliver something that kept AMD in check without completely upsetting the balancing of things. There's no technical reason that Intel couldn't have enabled Hyper Threading on the Core i5, it's purely a competitive move. A Core i5 750 with HT would not only defeat the purpose of most of the i7s, but it would also widen the performance gap with AMD. Intel doesn't need to maintain a huge performance advantage, just one that's good enough. While I'd love to have a 750 with HT, I'd still recommend one without it.
The Core i7 870 gets close enough to the Core i7 975 that I'm having a hard time justifying the LGA-1366 platform at all. As I see it, LGA-1366 has a few advantages:
1) High-end multi-GPU Performance
2) Stock Voltage Overclocking
3) Future support for 6-core Gulftown CPUs
If that list doesn't make you flinch, then Lynnfield is perfect. You'll save a bunch on a motherboard and the CPUs start at $196 instead of $284. We didn't have enough time with our Core i7 860 to include performance results here but my instincts tell me that at $284 that'll be the Lynnfield sweetspot. You get excellent turbo modes and Hyper Threading, without breaking $300.
Speaking of turbo, I'd say that Intel is definitely on to something here. The performance impact was small with Bloomfield, but turbo on Lynnfield is huge. My tests showed up to a 17% increase in performance depending on the workload, with most CPU-influenced scenarios seeing at least 9 or 10%. The turbo mode transitions happen fast enough to accelerate even simple actions like opening a new window. OS and application responsiveness is significantly improved as a result and it's something that you can actually feel when using a Lynnfield machine. It all works so seamlessly, you just always get the best performance you need. It's like Intel crammed the best single, dual and quad-core processors all into one package.
Perhaps that's what kept me from falling in love with Bloomfield right away. It was fast but in the same way that its predecessors were fast. If you didn't have a well threaded application, Bloomfield wasn't any better than a similarly clocked Penryn. Lynnfield's turbo modes change the game. Say goodbye to tradeoffs, the Core i5 and Core i7 are now fast regardless of thread count. It speed that is useful, it speed that you can feel, it's what truly makes Lynnfield the best desktop microprocessor of 2009. It's not just faster, it's smarter, it's better. It's why today's title borrows from Daft Punk and not Star Wars; it's not more of the same, it's something futuristic and new.
Lynnfield shows us the beginning of how all microprocessors are going to be made in the future. Even AMD is embracing turbo, we'll see it with Fusion in 2011. Extend turbo to its logical conclusion and you end up with something very exciting. Imagine a processor made up of many different cores, large and small, CPU and GPU. Each one turning on/off depending on the type of workload, and each running as fast as possible without dissipating more heat than your system can handle.
My only two complaints with Lynnfield are that the chips do require additional voltage (above stock) to overclock and of course the lack of Hyper Threading on the Core i5. It doesn't ruin the processor, but it gives us something to wish for.
Our work is never over.
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Seramics - Wednesday, September 9, 2009 - link
So what's the big deal here? I dun tink its that impressive, just good. While S196 of 750 look to outcompete the "way" more expensive $245 of AMD's 965, the truth is that the mobo that you need to pair the 750/860/870 is far from being competitive. P55 is severely stripped down and it is only slightly cheaper than their X58 counterpart. So wht if 750 is cheaper than 965 by about %50? Did you just buy the cpu only? Ppl shud at least look at the CPU+mobo price because they both come together. Truth is, when you take into account mobo price, 750 is far from outcompete 965. Added up, I think its only about balanced. The 750 is a better CPU, but it also cost more. In comparison to their socket 1366 partner, socket 1156 system cost a little less, but they are also inferior a little bit. So what's special them? Sure, there are better turbo and better thermal performance. For me, that is all that is good about the 1156 CPU. For enthusiast, socket 1366 is the way to go.jnr0077 - Friday, July 27, 2012 - link
i have a i5 750 chip cost £100 a gigabyte GA-P55A-UD6 cost £100 as it has six ram slots 16gb max radeon hd 4850 i love this mobo i cant fault it for the price i find it is a brilliant upgrade for cost i spent £250 considering the price of shops build you own pc you get what you put in :) very happy with the i5 750 1156 socket windows score on basic 500gb 7200 is 5.9 sweet 7.9 with a ssd :) can anyone tell me what the amd 965 hit on base score as i will never DV8 to amd intel 4 me allways :)hob196 - Wednesday, September 9, 2009 - link
Hi,Thanks for another great article.
I figure that having PCI-e on chip would be great to reduce the latency. Any thoughts about plugging non graphics PCI-e cards into the second PCI-e slot?
I've heard some motherboards cripple the 2nd slots performance down to x1 if you plug an x1 card in the other slot (in a shared x8 environment)any evidence of this?
In case you're curious I work with digital audio in a studio environment and I'm always striving to reduce the latency of audio going through the CPU.
These days, the latency (in streaming audio) is down to how fast the CPU can push floating point plus any overhead for the buffers in the various busses you go through. e.g. A firewire sound interface adds a few ms because of the inherent buffers between CPU -> Northbridge -> Southbridge -> Firewire -> Interface.
tempestor - Wednesday, September 9, 2009 - link
Another great article Anand!You should consider a 2nd job as a novel writer! :D
lp, M.
AndyKH - Wednesday, September 9, 2009 - link
I don't really get it:It is stated that most PCIe cards don't work well with higher frequencies and that the BCLK frequency should be kept at multiples of 133 MHz, and then they overclock it using a BCLK of ~200 MHz in one instance???
Doesn't the 133 MHz requirement make it pretty much impossible to overclock?
Someone please enlighten me.
Anand Lal Shimpi - Wednesday, September 9, 2009 - link
It doesn't make it impossible to overclock, just impossible to overclock (very high) without additional voltage.Take care,
Anand
AndyKH - Thursday, September 10, 2009 - link
Thank you for the response!I see how using a higher voltage will increase switching speed of the buffers driving the PCIe bus. However, I fail to see why it would make it any less dificult for PCIe cards to cope with the increased clock frequency, unless the increased voltage is also fed to the PCIe cards (is this the case?). Otherwise I assume they would surely experience the same problems driving communication to the CPU?
Also, you write multiples of 133 MHz but overclock to 200 MHz BCLK. Shouldn't it read multiples of 33 MHz?
TotalLamer - Wednesday, September 9, 2009 - link
I really, really don't understand why Anand is so obsessed with Turbo Modes. Any enthusiast who dares call himself such is going to clock this chip to the moon, at which point Turbo doesn't do anything. So with a 4.2GHz i7 870, all you're really left with is an i7 920 with worse multi-GPU gaming performance and and a less-certain upgrade path.coconutboy - Wednesday, September 9, 2009 - link
You're assuming all enthusiasts think like you do, but the heavy majority of people (enthusiast or not) want nothing to do with a $500+ i7 870 cpu. The i7 920, 860, and i5 920 are much more attractive options.There are plenty of "enthusiasts" who instead prefer silent computers that use no fans, or people living in hot climates who focus on very low temps, or all manner of different things. On top of that, the overwhelming majority of people simply do not care about any of the aforementioned, and those people buy the heavy majority of computers.
I started OCing in 1996, and used to OC pretty heavily, but got tired of constant tweaking or seeing my well-worn parts die prematurely. Now I tend to focus on very quiet computers that have a small/moderate overclock. So taking an i5 750 or i7 860 and raising it up 200-400 MHz and leaving turbo on is very appealing to me. Also of note is the extra heat generated and the extra money I'll spend on my electric bill by having a 24/7 overclock versus turbo modes. Dig the link and scroll to the bottom-
http://www.guru3d.com/article/core-i5-750-core-i7-...">http://www.guru3d.com/article/core-i5-750-core-i7-...
review-test/10
The 13 watt increase at idle is no big deal, but 133 extra watts under load, well... it's worth the performance boost and heat to some folks, but other people (like me) look at those things as tradeoffs that need to be weighed versus reliability, cost for extra cooling, noise, my electric bill etc.
Skiprudder - Thursday, September 10, 2009 - link
I think that some of us are quite honestly getting more green conscious these days too. It's nice to have a CPU this fast that's also this energy efficient. We can get similar to OCed performance at a much smaller power envelope. I know it doesn't add up to a lot over the course of a year (less than $100 I assume), but these things add up and it saves me some dinero on the power bills!