LGA 2011 and Sandy Bridge-E News from IDF 2011

Our final report from IDF 2011 is solely devoted to Sandy Bridge-E processors and LGA2011 platform. We gathered together everything that we learned about the upcoming processors, cooling systems and mainboards, and also found out how the new platform will overclock and what we could expect from the six-core Sandy Bridge-E CPUs.

by Anna Filatova
09/16/2011 | 04:17 AM

On the last day of the IDF 2001 that took place in San Francisco, California, we decided to take a break from keynotes and technical sessions and walk around the showcase in order to find out the exciting details about the new Intel desktop processors, which should come out shortly. Yes, I am talking about the Sandy Bridge-E modifications targeted for computer enthusiasts and designed for use in a not yet announced LGA 2011 platform on Intel X79 Express chipset.

LGA 2011: New Functionality Overview


Frankly speaking, Intel wasn’t very eager to reveal a lot of details about the new Sandy Bridge-E and LGA 2011. And there are several reasons behind it. Obviously, we already know everything we wanted to know about these new products. They will come out very soon, so at this point you can even find some benchmark results of the engineering samples available online. The second reason why Intel was so restrained is the fact that there is not that much to tell about these CPUs, because they can’t boast any unique technological innovations. Sandy Bridge-E is the same exact Sandy Bridge, and for the most part the differences are actually in the number of processor cores and the connection between them.

In fact, the next slide shows very clearly that there won’t be anything particularly new about the Sandy Bridge-E processors and LGA 2011 platforms, which Intel codenamed Waimea Bay.

Desktop Sandy Bridge-E processors will be manufactured using well-familiar 32 nm production process and will have 4 or 6 computational cores depending on the CPU model. Note that they will lose the graphics core, but instead they will get a larger L3 cache and an enhanced four-channel memory controller supporting DDR3-1333. The L3 cache in this case will be 15 MB large. In other words, the main advantage of the upcoming LGA 2011 platform will be very high performance, which must be delivered at any price:

Unlike LGA 1155, the new LGA 2011 platform is aimed at experienced enthusiasts and gaming fans that is why Intel pays special attention to the ability to use high-performance graphics sub-systems made of several graphics accelerators. LGA 2011 systems have as many as 36 PCI Express 2.0 lanes. And by the way, Intel said that they will also support PCI Express 3.0, although at this point they haven’t even passed their certification yet. Later on, however, when actual AMD and Nvidia graphics cards featuring this interface come out, they will all work at full speed, without losing any of the graphics bus speed.

In fact, LGA 2011 is a continuation to the LGA 1366 platform that is why Intel makes sure you know that Waimea Bay will have native SATA 6 Gbps support.

However, in reality the new platform differs much more from the LGA 1366 one. And these differences primarily come from its structure. The thing is that Intel X79 Express chipset will not be a new fully-functional two-chip chipset, like Intel X58, for example, but will shrink to just one South Bridge chip. So the PCI Express bus support comes from the CPU as well as regular Sandy Bridge processors for LGA 1155.

As for the functionality of the new Intel X79 chipset, it will be very similar to the functionality of the other chipsets for LGA 1155 platform.

We can’t say that X79 is a functionally modern chipset. It doesn’t even have USB 3.0 ports. However, the number of supported SATA ports has been increased to 10, and the number of 6 Gbps ports – to 6. Overall, Intel is not trying to impress us with Waimea Bay platform functionality, and focuses mostly on its performance. And as for other hot contemporary add-ons, Intel makes it clear that it is the mainboard makers’ turf.

All this goodness should be announced in the middle of Q4 2011, so there is not so much waiting left at this point. The mainboard makers confirmed that they will announce three processor models on the launch day. Two of them will be six-core processors, and one – a quad-core CPU.

As you can clearly see, maximum frequencies of the new LGA 2011 processors will be higher than those of the LGA 1155 products, which don’t ever speed up past 3.8 GHz in Turbo Mode. Of course, the nominal frequency of the Core i7-2600K is 3.4 GHz, but it will obviously be slower than any of the LGA 2011 processors, because it will either have fewer cores, or will work at lower frequencies. In any case, it is inferior to the new Sandy Bridge-E processors in the number of supported memory channels as well as in the L3 cache size.

One Step Towards Overclockers

The most interesting thing about the new platform is not the processor specifications or chipset functionality, but the aspects that make LGA 2011 so appealing for overclockers. LGA 1155 wasn’t so attractive for overclocking fans. It turned out unable to allow overclocking processors by simply raising the BCLK frequency, which has immediately affected the number of overclocker systems built around Sandy Bridge. In fact, you had to have an unlocked processor, like Core i5-2500K or Core i7-2600K, to succeed. The moment first complaints about that started coming in, the company officials immediately responded that the users shouldn’t get too worried at this point because the upcoming LGA 2011 will be specifically designed for overclocking and will meet all their needs in time.

Now we finally saw what the new Intel platform for overclockers looks like.

Well, we have already seen from the processor specifications that two out of three models will have an unlocked multiplier, which will allow simple straight-forward overclocking. However, even a locked Core i7-3820 model will also be overclockable. Intel promises that the options allowing to increase the BCLK frequency will now work in a much trickier manner.

In fact, the old problems will not go anywhere. Just like on LGA 1155 platforms, PEG and DMI frequencies will be tied up to the base clock frequency generator, i.e. even a slight increase in Reference Clock will cause the same problems as with current Sandy Bridge. The good news is that in LGA 2011 systems the BCLK frequency will be additionally multiplied by an intermediate reference clock ratio multiplier before getting to the processor, and this multiplier will be at 1.0x, 1.25x or 1.67x. In other words, besides the traditional processor clock frequency multiplier, there will be an additional intermediate overclocking multiplier that will serve for overclocking by adjusting the “bus frequency” outside the CPU. This multiplier will raise the base clock of the processor and its functional units (including the memory controller), but leave it untouched for the I/O part. Moreover, this multiplier will exist for any LGA 2011 processors, even the ones with the locked multiplier. And frankly speaking, it doesn’t even belong to the CPU, as it is the chipset that is responsible for its operation. It means that it cannot possibly be locked in a processor.

As a result, we will no longer use the following traditional formula for the processor frequency:

[CPU Frequency] = [CPU Multiplier] x [Reference Clock].

Instead we will use the following one:

[CPU Frequency] = [CPU Multiplier] x [Reference Clock Ratio] x [Reference Clock],

where [Reference Clock Ratio] is this particular additional multiplier of 1.0x, 1.25x or 1.67x.

This little trick will allow overclocking LGA 2011 processors even without changing its actual multiplier at all. Just like in LGA 1155 systems, we can only adjust the reference clock slightly without losing any of the performance. In reality it means that when the BCLK frequency changes by ±5%, the system may become non-operational. But the additional reference clock ratio multiplier will allow us to send 125 or even 167 MHz frequency to the processor without changing the BCLK at all. This way both birds will be killed with one stone. The CPU will work as if it received 125 or 167 MHz base clock, while in reality DMI and PCI Express will be working at BCLK frequency of 100 MHz.

Moreover, LGA 2011 system will also allow memory overclocking, just like the LGA 1155 systems do. The nominal supported memory is the same DDR3-1067/1333, but with a 266 MHz increment you will be able to reach DDR3-2133 or even DDR3-2400. By the way, LGA 2011 platforms will support the new XMP version 1.3, which is intended specifically for four-channel memory with the frequency of 1866 MHz or higher.

In order to achieve stability during overclocking of an LGA 2011 system, we should be able to change three voltage settings: Vcore, Vmem and system agent voltage.

Intel shared with us some of their overclocking success. They used a boxed water-cooler, which we are going to discuss a little later in this review. Although it can’t boast better cooling efficiency than a high-performance air-cooler, the Core i7-3960X processor overclocked to 4.75 GHz.

By the way, I would like to draw your attention to the fact that this is a very unusual overclocking for Sandy Bridge, but it confirms everything we have just said above. This system uses 95 MHz reference clock. However, at the same time it also uses the additional Reference Clock Ratio of 1.25x. As a result, the processor received “modified” bus frequency of 119 MHz. Taking into account the 40x multiplier, the processor frequency comes to 4.754 GHz. This is how tricky it is :)

The memory in this case works as DDR3-2218 and the Reference Clock Ration of 1.25x also applies to it, because the system originally has DDR3-1866 mode set it in by default. You can check out the voltages and timings on the photo above.

And the next image shows the actual system that was used for all these overclocking experiments.

Overclocking to 4.75 GHz, performed by Intel specialists, doesn’t strike you as something super-natural. So, it turns out that Sandy Bridge-E processors for LGA 2011 will overclock pretty much as good as the existing Sandy Bridge processors for LGA 1155. However, we didn’t expect anything different here, because nothing has actually changed in the production process as well as microarchitecture. Only the number of cores has increased and so did the TDP. This means you might want to consider getting a better cooler, but it is not a reason enough to assume that the new LGA 2011 processors should be more or less overclockable.

Cooling Systems for Sandy Bridge-E

Since we mentioned better coolers, we have to say that Intel has been discussing the possibility to use liquid-cooling systems for their LGA 2011 processors for a long time now. And at this IDF we saw that it was indeed so. The top Sandy Bridge-E processors will be bundled with a special liquid-cooling system from Intel – RTS2011C.

We saw it in action in the overclocked system we mentioned above:

The default RTS2011C liquid-cooling system, which will be shipped with Intel LGA 2011 processor, is made by Asetek. They supply their OEM systems to many manufacturers, including such well-known names as Corsair, for example. This system includes a water block with a copper base and built-in pump and a 150 mm radiator, which weighs quite a lot (820 g). The radiator is topped with a 120 mm fan with blue LEDs in it, which rotates at 800-2200 RPM. According to Intel, it should generated anywhere between 21 and 35 dBA of noise.

Intel’s liquid-cooling system looks very similar to Corsair Hydro H70.

In fact, don’t assume that the new LGA 2011 processors will have such catastrophic heat dissipation that the liquid-cooling system will be a must. Of course, 130 W TDP is significantly higher than what Sandy Bridge for LGA 1155 had, but there is nothing to be afraid of here. Intel is simply trying to offer overclockers a good option for consideration. In reality, a good air-cooler with heatpipes may be more than enough.

We saw a corresponding cooling solution at the Dynatron booth.

A cooler like that using heat-pipe direct-contact technology will serve the purpose perfectly not only in nominal mode but also during overclocking experiments on the new LGA 2011 platform.

Mainboards for LGA 2011

It looks like everything is ready for the launch of Sandy Bridge-E and Waimea Bay platform. For example, mainboard manufacturers proudly displayed their products for the new Intel processors. And these were not just some dummy boards, but the actual operational products.


Of course, we must begin our mainboards tour from Intel products. Core i7-3960X overclocking was performed on their own Intel DX79SI mainboard. Here it is:

Eight DDR3 DIMM slots for four-channel memory on both sides of the processor socket and three PCI Express x16 slots for the graphics cards (working as x15, x16 and x18 respectively) – this is a typical LGA 2011 solution. The unique thing about this mainboard is that the processor voltage regulator circuitry is split in two parts and is placed on the opposite sides of the LGA 2011 processor socket. Moreover, the board has only two SATA-600 and two SATA-300 ports and a pretty boring back panel.

There are only six USB 2.0 ports, two USB 3.0 ports, two Gigabit network ports, sound and one IEEE1394 port. And do you know why that is so? The thing is that they removed SAS support from the chipset the very last minute, otherwise the chipset functionality would have been much richer. However, since the chipset functionality has changed, Intel had to get rid of several ports, but they didn’t put anything else into the free spots after that.

Intel DX79SI mainboard has several indisputably great features. Intel has finally decided to be good to overclockers, that is why the board not only boasts a functionally rich BIOS, but is also equipped with a POST controller, Power On and Resent buttons on the board and a Clear CMOS button on the back panel.

But Intel wasn’t the only one with the boards for the new LGA 2011 platform ready. MSI and Gigabyte also didn’t waste any time. Since the LGA 2011 platform is targeted primarily for computer enthusiasts and Intel has no plans so far to launch any low-cost CPU models for it, it seems like we won’t see any inexpensive mainboards for LGA 2011 as well. At least, the mainboards showcased at Gigabyte and MSI booths are far from being budget products, even though they both offer more as well as less expensive solutions.


Let’s take a quick look at the models available from these two mainboard makers. Let’s start with Gigabyte GA-X79-UD7:

The board is designed in an eye-catching overclocking-friendly color scheme (the legendary GA-X58A-OC uses the same exact colors). It features a special 20-channel overclocking-friendly VRM, which is specifically designed for overclocking needs. In other words, it is a great choice for the biggest enthusiasts. The mainboard has special buttons for “on the fly” CPU overclocking, seven 4-pin fan connectors and other overclocking-related features, such as voltage contact spots. In other words, this is a product fit for enthusiasts.

Here comes the new mainstream model – Gigabyte GA-X79-UD5:

This is a common work horse with a 12-phase voltage regulator circuitry and 3-way SLI and Crossfire support. By the way, note that the following is true for most LGA 2011 mainboards: the first two PCIe slots, which the processor is responsible for, will support PCI Express 3.0, while the third slot connected to the Intel X79 chipset lanes will be able to work only as PCI Express 2.0. Both Gigabyte mainboards boast an impressive number of SATA ports. In this particular case there are as many as 14 of them.

One of the memory makers, the Kingston Company, had 64 GB of system memory working perfectly fine in a Gigabyte GA-X79-UD5 mainboard like that.

Kingston is planning on offering a corresponding 64 GB HyperX memory kit of eight 8 GB modules by the time LGA 2011 is ready to launch.

And this is another board – Gigabyte GA-X79-UD3:

This seems to be the simplest Gigabyte mainboards for the new Sandy Bridge-E processors. This board even has only four DDR3 DIMM slots – one per each channel. Its voltage regulator circuitry has only 8 phases. Nevertheless, there are four PCI Express x16 slots like on UD7, and twelve SATA ports.

Gigabyte will also continue to offer users their gaming products from the G1.Killer series designed to support LGA 2011 processors. Here is G1.Assassin 2 mainboard:

Honestly, if we disregard the black-and-green color scheme, it will seem very similar to an inexpensive UD3 board. There are only four memory slots and the voltage regulator circuitry has 8 phases. However, this design was created because Gigabyte engineers ran out of PCB space for the gaming features such as Creative sound and network built with a Bigfoot Networks Killer E2100 controller. So, they had to sacrifice a few things.

However the most interesting feature of the showcased Gigabyte's LGA 2011 mainboards is their decision to finally use UEFI instead of their old-school text BIOS. This is what the new interface will look like:


Now let’s look at a few MSI offerings. The first board is MSI X79A-GD45:

This one also has only four DIMM slots and only three PCI Express graphics card slots.

The next MSI mainboard, X79A-GD65, is a little more expensive:

Here we again see only four memory slots, but there are five PCI Express x16 slots instead. Besides, we got a few buttons for CPU overclocking and contact spots where you could read the voltages using a conventional multi-meter.

But if you want to put the maximum amount of memory in, MSI can offer you a special mainboard modification with eight DDR3 DIMM slots called X79A-GD65 (8D):

This one has not only more DIMM slots, but also a more powerful VRM circuitry.

Final Remarks

Everything we saw this week that was related to the upcoming LGA 20111 platform proves that it is going to launch very shortly. The mainboard makers suspect that at this time the launch is planned for some time in mid November, but Intel may push this important even to an earlier date just as easily. So, AMD Bulldozer processors won’t be enjoying their leadership for long: they should soon face a very serious opponent.

The following slide will give you some idea about the performance of the Sandy Bridge-E processors. Here we compare Core i7-3960X against Core i7-990X for LGA 1366.

As we see, even though these are both six-core CPUs, and i7-990X even works at 166 MHz higher clock frequency, Sandy Bridge-E is indisputably far ahead. So, the upcoming LGA 2011 platform should undoubtedly have a great future in the enthusiast segment.