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
Lynnfield's Un-Core: Faster Than Most Bloomfields
A few years ago I had a bet going with AMD's Ian McNaughton. We were at an AMD event where the Phenom architecture was first being introduced and he insisted that the L3 cache was part of the memory controller. This didn't make any sense to me so I disagreed. Minutes later a presentation slide went up on a projector talking about how the L3 cache and memory controller were on the same voltage plane; that's what he meant. Ian laughed a lot and to this day he holds it over my head.
The moral of the story is in Phenom and later in Nehalem, the processor is divided into two parts. Intel named them the core and the un-core. The "core" of these multi-core processors is made up of each individual processor core and its associated private caches (L1/L2). The "uncore" refers to everything else: PCIe controller, memory controller, DMI/QPI and the L3 cache.
The uncore isn't as critical for performance but is made up of a ton of transistors; roughly 400 million in the case of Lynnfield/Bloomfield (more if you count the PCIe controller). In order to save power, Intel uses slower transistors that have lower leakage for the un-core. As a result, the un-core can't clock up as high as the core and runs at a lower multiplier.
Take the Bloomfield Core i7 975 for example. The core runs at 25x BCLK (25 x 133MHz = 3.33GHz), but the un-core runs at 20x BCLK (20 x 133MHz = 2.66GHz). The rest of the chips, including Lynnfield, have slower un-cores:
| CPU | Socket | Core Clock | Un-Core Clock |
| Intel Core i7 975 Extreme | LGA-1366 | 3.33GHz | 2.66GHz |
| Intel Core i7 965 Extreme | LGA-1366 | 3.20GHz | 2.66GHz |
| Intel Core i7 950 | LGA-1366 | 3.06GHz | 2.13GHz |
| Intel Core i7 940 | LGA-1366 | 2.93GHz | 2.13GHz |
| Intel Core i7 920 | LGA-1366 | 2.66GHz | 2.13GHz |
| Intel Core i7 870 | LGA-1156 | 2.93GHz | 2.40GHz |
| Intel Core i7 860 | LGA-1156 | 2.80GHz | 2.40GHz |
| Intel Core i5 750 | LGA-1156 | 2.66GHz | 2.13GHz |
Here's another area where Lynnfield is better than the lower end Bloomfields: its uncore runs at 2.40GHz instead of 2.13GHz. The exception being the Core i5 750, its uncore is stuck at 2.13GHz as well. Once again, only the "Extreme" Bloomfields have a faster uncore.
Lynnfield's Memory Controller: Also Faster than Bloomfield
Intel only officially supports two memory speeds on Bloomfield: DDR3-800 and DDR3-1066. Obviously we're able to run it much faster than that, but this is what's officially validated and supported on the processors.
Lynnfield is a year newer and thus gets a tweaked memory controller. The result? Official DDR3-1333 support.
Three Lynnfield memory kits (left to right): OCZ, Patriot and Kingston
The same sort of rules apply to Lynnfield memory kits that we saw with Bloomfield. You don't want to go above 1.65V and thus all the kits we've seen run at 1.5V for the stock JEDEC speeds or 1.65V for the overclocked modules.
Like Bloomfield, 1.65V is the max we'll see on Lynnfield
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maddoctor - Tuesday, September 8, 2009 - link
Yeah, I'm agree. I think AMD will be no more as a company next year. I hope it will be happen. I think it is better you throw your AMD rubbish products into the trash. Because, I don't see any valuable of it.Eeqmcsq - Tuesday, September 8, 2009 - link
Well, I hope that it does NOT happen, because we NEED competition to keep Intel honest. Secondly, I would not go as far as calling AMD stuff rubbish. They're good if they fit one's needs at the right price, but they are definitely getting pushed further down the totem pole.JonnyDough - Tuesday, September 8, 2009 - link
KEEP them honest? Where have you been?bupkus - Tuesday, September 8, 2009 - link
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.maddoctor - Tuesday, September 8, 2009 - link
I don't believe Intel will increasing its products because AMD does not have any competitive products.klatscho - Tuesday, September 8, 2009 - link
actually, they do - if you would care to have a look at price/performance, especially considering that amd has already quietly thinned out its portfolio to make room for price improvements in order to stay in the game.maddoctor - Tuesday, September 8, 2009 - link
Intel doesn't need to be honest. I hope Intel will lifts AMD licensee as AMD has been breached the Intel - AMD CLA. I believe Intel will always be innovating and makes more cheaper and performance wise products. AMD will be no more and you will not need to miss it, AMD had been doing its duty to made Intel more stronger and competitive.PrinceGaz - Tuesday, September 8, 2009 - link
You are a fool if you think AMD is no longer needed. The only reason these Lynnfield chips start at just $196 is because AMD is still here and were selling competitive chips at around that price point. No AMD means newer better chips are introduced at high price points and stay there for a long time, just look at Bloomfield's prices to see what happens when AMD offers no competition. The $284 i7 920 is for a slightly higher performing chip than any Phenom and is priced accordingly, but you have to pay $562 and then $999 for performance where there is truly no competition.No AMD would mean these Lynnfields starting at $284 if you're lucky (that's for something like the i5 750) with the HT enabled ones at the $562 price point, and the only chips you'd find for under $200 would be old Core 2 Duos and Quads. Thankfully AMD are here which is why new chips are introduced at competitive prices. No competition (from AMD) means no competitive prices, so if AMD go bust today, the next generation of Intel chips will start expensive, and stay expensive until they are replaced with the model after it, which won't be for a long time when nobody else can offer anything like their current product. I guess you don't remember the days of the original Pentium in the mid 90's.
ClagMaster - Tuesday, September 8, 2009 - link
I agree. We need AMD and it's foolish to assert otherwise.AMD has been very good to us over the last 10 years. If it was not for AMD, Intel would have a monopoly and we would have not have Lynnfield or Bloomfield today. Intel created Lynnfield because they wanted to be more competitive with AMD in the mainstream market. Bloomfield/X58 was simply too expensive for mainstream and AMD's Phenon II was a better value.
I am discouraged that people have so easily forgotten AMD's past leadership such as the efficient instruction schedulers, first on-chip memory controller,the first single-die dual and quad core chips to market, the first consumer 64-bit processors, the x86-64 architecture extension that Intel followed, and the K8 architecture that kicked Intel Netburst architecture's butt black and blue.
That's why Intel was motivated to drop Netburst and introduce the Core 2 Duo/P965 in 1996. Then adopt the aggressive tick-tock strategy ever since that has given us the 45nm Lynnfield today. Lynnfield has these AMD inspired innovations, and Intel has built upon these innovations with the on-die PCIe controller.
I have a lot of respect for AMD. Don't ever accuse AMD of not being innovative. AMD does not suffer from lack of technological innovation. They have demonstrated plenty of innovation. AMD suffers from lack of capital investment that allows acceleration of technological development and manufacturing infrastructure.
strikeback03 - Wednesday, September 9, 2009 - link
You can't really say Lynnfield is a response to PhenomII when it was on the Intel roadmap before they knew how PhenomII would perform or be priced. It is simply the next progression in their architecture. So you might be able to argue that Intel wouldn't have rolled out the Nehalem architecture as quickly without AMD, but you can't really say any one family is a response to another in that short a timescale.