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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Scheme - Tuesday, September 8, 2009 - link
Why is it assumed enthusiasts or technical users are only interested in overclocking? For me it's about balancing performance, temps, noise levels and power consumption, all with a reasonable cost of entry. All that considered Lynnfield seems to be a good platform.Ann3x - Tuesday, September 8, 2009 - link
Well the d0 can usually hit 3.8-4ghz on std voltages.So tbh temps dont really come into it. Anyone with a 920 should overclock it because there is really nothing to lose. No need to risk the cpu, negligible temperature increases, its all positive.
If you buy a 920 and dont overclock you either should have a very good reason or you dont know how to.
The 920 is a very meh processor at stock. The reason its so popular is its potential to overclock so easily and so highly not its stock speeds.
Scheme - Tuesday, September 8, 2009 - link
3.8-4ghz will involve more than what I'd consider to be 'negligible temperature increases'.Ann3x - Tuesday, September 8, 2009 - link
I can hit 4Ghz on air with stock voltage with a max load (10hrs of LinX) of 65C. Thats so far within the thermal limits of the CPU to be considered totally negligible. My results seem very typical for d0 920s.Enthusiast CPUs need to be treated (and reviewed) in context with their market. If some people are too stupid to see the potential of their mid range CPUs then Id at least expect a good site like anandtech to realise it and not act like stock is the only option.
There is a reason why 90% of X58 motherboards are marketed on their overclock and performance options.
erple2 - Tuesday, September 8, 2009 - link
I'm a bit more interested in relatively low power consumption, and stable (as in for 4 years) operation, not how many fractional increases in performance I can eke out of a CPU at potentially catastrophic failure rates through overclocking. However, I'm buying a CPU for it's solid performance, reliability (the i7's haven't been out long enough to make any judgement of it's long term reliability), and lower power consumption. Also, can you still claim RMA status on a broken CPU that was potentially damaged by overclocking? I haven't read any Intel literature to suggest that you can.I don't care at all about what you think I my goals with buying a CPU for are. Your class of "enthusiast" is really "the overclocking user", not the "enthusiast".
I suppose it would be more interesting to find out how many of the X58 purchasers actually overclock their CPUs (beyond what "turbo" buys you), and then make conclusions, rather than this handwaving "you're an idiot if you do something other than what I do" mentality that you are showing.
I'd also like to see how many of those "90% of X58 mobos marketed on their overclock and performance options" (reference please!) are actually sold vs. those that are cheaper, and not marketed on overclocking performance. Maybe that "other 10%" sells about 40-50% of the market. Do you have data to suggest otherwise?
Ann3x - Wednesday, September 9, 2009 - link
You really think you can damage a cpu by just increasing the clock? Wow.Only things that damage CPUs are overvolting (not needed for a decent OC on the i7) and high temps (usually linked directly to overvolting). The concept that an overclock at stock voltage could cause "catastrophic failure" is frankly laughable.
A sensible overclock will be no more or less stable than stock. The only people who actually risk system stability are the ones who overvolt and push the limits. For the record 3.8-4ghz is most definitely NOT pushing the limits.
Again ill say it. If youre buying an X58 motherboard you are PAYING for the ability to overclock. If you choose not to there is little - no point in the platform (with the possible exception of people who use very multi threaded apps). The proof in this point is actually staring you in the face in the i5/new i7, their design shows that intel realises the headroom they have in the architecture. The aggressive turbo mode of the i5/new i7 is proof that there is NO risk in overclocking within sensible limits at stock voltage.
In reality the main "huge leap forward" of the new platform is simply the acceptance of overclocking within intel.
That you choose to ignore the potential of your CPU is your own loss. Intel think its safe to overclock but hey, you know better right :). Im just surprised that anand chooses to for the most part ignore this and makes absurb attention grabbing statements instead of assessing the real merits of the 2 platforms. It really is a rose tinted glasses review but oh well. Keep your heads stuck in the sand.
yacoub - Tuesday, September 8, 2009 - link
Great article except it would have been REALLY nice to have the i7 860 data, given that's most likely the best bang-for-the-buck Lynnfield option and it probably makes MUCH more sense price-wise than going for the 870. It REALLY sucks not knowing where that chip slots in for all the tests you did.This is exactly the concern I listed when the polls were posted that asked which CPU we most wanted to see benchmarked. Clearly we want to see ALL THREE.
That said, it's nice to see Lynnfield is basically awesome, except in Crossfire/SLI which is about the LAST thing I could give a crap about. So really, this looks about perfect. (Only on page 14 though, but if it continues as it has to this point, I'm sold.) I just wish the 860 had been benchmarked.
Gary Key - Tuesday, September 8, 2009 - link
I have the 860 in the upcoming mb roundups. :)yacoub - Tuesday, September 8, 2009 - link
I knew there was a reason we all love us some Gary Key. \m/. :)529th - Tuesday, September 8, 2009 - link
I'm not sure what bios setting is Sleep State on the i7 9xx (1366) but for discussions sake, say C1E sleep state is disabled, as overclockers usually do this, does that negate the logical functioning of Turbo mode and run all cores at the max TDP & speed? So would a 1366 system be faster with turbo & C1E sleep state disabled? ...i'm not even sure if i'm asking that right.. i'm still reading up on the PCU and Turbo section