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Intel's Lynnfield and Havendale

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By eachus
February 11, 2009

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In my copious spare time, I've been catching up on Intel's code names and plans, especially Lynnfield and Havendale. I'm probably posting this here rather than on the Intel board because, net, net, the news is probably better for AMD than Intel.

First, some details. Lynnfield will be the DDR3 only mainstream replacement for the quad-core Core 2 chips. It has two, not three, memory controllers, and requires a new socket. (Shades of AM3, but...) This is a different socket--LGA-1156--from the Core i7 family. The new socket has 16 lanes of PCI Express and also support for integrated graphics chips.

Don't look for Lynnfield in stores anytime soon.* DDR3 prices have been dropping, but recently so has DDR2 due to oversupply. The crossover point (where similar DDR2 and DDR3 parts cost the same amount) was originally expected late this year, then at the end of the first quarter, and now back out again. Life in the semiconductor manufacturing business can be fun, but for memory chip companies, it is pretty painful. Is there a benefit to having PCIe on-chip? Not really. The reduced latency of access to main memory will help low-end graphics cards that have a small on GPU cache, and use some of main memory to back that cache. However, cards with 512 Meg or more of graphics memory won't see any benefit.

One potential benefit which I don't see most motherboards supporting is that you could have one graphics card hanging off the CPU, and one off the Northbridge. Then again most mainstream computers don't use multiple graphics cards, and certainly don't ship that way. Besides, Lynnfield does support splitting those 16 lanes into two sets of eight. I don't know how the licensing will sort out, but I certainly expect nVidia to provide Lynnfield chipsets that include an SLI license.

AMD's Socket AM3 introduction with its evolution not revolution philosophy looks like a big win for now. For the record, the new Phenom II chips will work with DDR3 in Socket AM3 motherboards, with DDR2 in Socket AM2+ motherboards, and may work fine in Socket AM2 motherboards. (But you lose some power saving functionality.)

Some people may do an incremental upgrade, buying a new Phenom II for their current system, then upgrading to a Socket AM3 motherboard and a new CPU later. It is certainly possible, but I don't expect it to happen with the just introduced Phenom IIs. Look for AMD to start selling (probably including 125 watt) high end Phenom IIs that go beyond the 940 later this year. Those may tempt some upgraders. But it shows the real benefit to AMD of the strategy. AMD can migrate to all Socket AM3 parts this year with no concern about when OEMs will switch to shipping DDR3 in systems. (Yes, Intel has that advantage with the current Core 2 line. But i7 and i5 to come are DDR3 only.)

Intel is going to be seeing very limited Lynnfield CPU orders from OEMs for now.* And since Lynnfield/i5 requires a new socket, and is not aimed at the performance market in any case, I don't see many LGA-1156 showing up in stores soon.

What about Havendale? The latest word is that it has been canceled. Take that with a small grain of salt, but not much is needed. The corresponding story is that Intel's 32 nm process is doing better than expected, and that Clarkdale the follow on to Havendale will be ready late this year: I'll stay agnostic for now as to whether Clarkdale will show up before year end. Especially given the Lynnfield slip. Again, not a technical decision but a marketing call. I think the (32 nm) mobile versions may come sooner than mainstream/economy lines.

The mobile version of Lynnfield is Clarkfield. Don't get confused. (Hey, I didn't choose those code names, Intel did. ;-) I don't know if it will get more or less traction than Lynnfield this year. Like Havendale and Clarkdale it will use a multi-chip package to combine it with a 45-nm die containing the memory controller and (integrated) graphics.

The net result of all of this, as I said, is probably good news for AMD. Even if AMD has inventory problems similar to Intel's, in AMD's case OEMs won't have to make painful decisions, and AMD is even more insulated from the DDR2/DDR3 switchover. AMD does have headroom in their 45 nm products, and we should see some announcements next quarter of faster DDR3 versions. IMNSHO, the big worry AMD has as far as their product line goes, is the obsolete Socket F for Opterons. Shanghai has the same DDR2/DDR3 agnostic memory controller. But Socket G4 is needed for the high-end features of HT3.0.

What about Intel's current die size advantage on the desktop? AMD does have the solution in the pipeline, and I referred to it in passing above. Technically there is a triple-core chip with shared L3 cache, Heka. AFAIK, the triple core chips introduced this month are not Heka, but if they become popular, AMD can produce them instead of using Deneb chips with a failed CPU. Propus, Rana, and Regor are CPUs without L3. Propus and Rana should be about half the size of CPU dies with 6 Meg L3. Regor IMNSHO is the speed demon chip AMD should have been making long ago, as (65 nm) Kuma.

Why do I call Regor a speed demon? Two reasons, first in the same system you can draw twice as much power per core as (quad-core) Deneb without overheating, or blowing power transistors. Not that big a deal for regular users, but the overclockers will love it. Second, the 1 Meg of L2 per core. I've commented before that, for most applications, the Shanghai family are L3 cache agnostic with fast DDR3. When you double the L2 core, the L3 becomes a liability. As of last I heard, the L2 in Regor does not give up any clock cycles to compensate for the size. So you get a faster running CPU core, bigger L2, and lower memory latency than other Shanghai chips.

What's not to like? Well, if you really need more than two cores, you may notice the difference, but for example, two 3.2 GHz cores should beat three 2.2 GHz cores, even on the most multi-threaded applications. For most gamers though, Regor vs. Propus and Deneb should be an interesting comparison. ;-)

* Just to avoid confusing anyone, the earliest i5/Lynnfield systems will show up in stores is this summer [or] fall, probably as part of the holiday season refresh. However, OEMs are already ordering CPUs for systems that will sell then. Part of the fun of being a big OEM. The (very recent) change from summer to fall, with October for official release probably has nothing to do with engineering problems, and everything to do with DDR3 prices. Mid-February is probably the last possible point for Intel make the slip decision, and there is no reasonable way to reverse it.