ASUS TUF Sabertooth X79 review

Military rugged motherboards - just the way we like 'em

Wherever there is high-end computer gear released, there's always ASUS. The release of Sandy bridge-E based CPUs and X79 chipsets ignites an entirely new series of motherboards. For X79 ASUS from top to bottom will fill up the line of X79 products gladly.

As such, as far as X79 reviews go we have arranged two motherboards to be reviewed, their all new Rampage IV but also the much more affordable TUF series, the TUF Sabertooth X79. And exactly that motherboard we will cover in this specific review.

ASUS initially had a mild success with the Sabertooth series, they carefully launched just in the USA as a tryout, yet once the concept picked up, they noticed demand worldwide.

The TUF Sabertooth X79 from ASUS is designed with that all too familiar military feel to it, styled in the very same color as the earlier models with the ceramic design and feel to it, we can see a lot of resemblances alright.

But hey no tactical jacket anymore? This all new LGA2011 motherboard will be powered by a 8+2+2+2 phase Digi+ VRM power design, all the good yet also based on a fair price tag.

Anyway, head on over to the next page where we'll discuss the X79 chipset, the respective ASUS models. Then we'll throw a decent photo-shoot and a benchmark suite at the products and get an indication what performance is like with the Intel Core i7-3960X (Sandy Bridge-E) and X79 Platform.

Have a peek, and sure we know it, you will either love or hate the design but give it a chance as the motherboard is just loaded with interesting options.

The Intel X79 chipset and Sandy Bridge E processors

We'll first start off with a bit of an explanation about the new processors that ignited the X79 motherboard chipset. If you read the launch review then you know it's all about Sandy Bridge-E, the all new 'enhanced' slash 'enthusiast' version of what pretty much in a nutshell is the Sandy Bridge (Core i7 2600K) architecture, yet with some new features added and some others stripped away.

Simply put, you take all the good ingredients from Sandy Bridge, preferably add two cores, a slightly increased L3 cache and add a pinch of quad-channel memory. There is one exception to the rule, one Core i7 Sandy Bridge-E CPU that will remain a quad-core processor.

Intel has announced three Sandy Bridge-E class processors, namely the Core i7-3960X, the Core i7-3930K, and the Core i7-3820. Each will have different clock frequencies and a slightly changed L3 cache. The Core i7-3820 is a quad core processor, the other two are six-core processors.

Below, an overview of the main specs.

Processor	Base Clock	Max. Turbo Clock	Cores / Threads	L1 Cache	L2 Cache	L3 Cache	Memory	Interface	TDP
Core i7-3960X	3.3 GHz	3.9 GHz	6/12	64KB x6	256KB x6	15 MB	Quad-channel DDR3-1600	LGA 2011	130 W
Core i7-3930K	3.2 GHz	3.8 GHz	6/12	64KB x6	256KB x6	12 MB	Quad-channel DDR3-1600	LGA 2011	130 W
Core i7-3820	3.6 GHz	3.9 GHz	4/8	64KB x4	256KB x4	10 MB	Quad-channel DDR3-1600	LGA 2011	130 W
Core i7-2600K	3.4 GHz	3.8 GHz	4/8	64KB x4	256KB x4	8 MB	Dual-channel DDR3-1333	LGA 1155	95 W

What's interesting from a naming point of view is that Intel chooses three different suffixes for the processors, we have an X model, a K model and a 'normal' model. A little confusing, but it does make some sense:

• The “X” suffix is Intel’s Extreme Edition processors, this means the top-of-the-line unlocked processors.
• The “K” suffix denotes a slightly lower end processor yet with its multiplier unlocked.
• And the normal editions are pretty much mainstream without any enthusiast grade overclock options, meaning a locked multiplier.

Cache wise the L1 and L2 caches are 100% similar to Sandy Bridge:

• 32KB data and a 32KB instruction L1 cache per physical core.
• 256KB L2 cache per core.

The L3 cache differs though, Sandy Bridge has one 2 MB slice of L3 cache per core, that's 8 MB for say the 2600K processor. The Core i7-3960X tested in this article has 15MB of L3 cache, meaning 2.5 MB per core (it's a single block of cache as it's shared).

L3 cache then, the six-core Core i7-3930K processor will get 12 MB (= 2 MB per core) and the Core i7-3820 will get 2 MB per core as well. So just one SKU has a 2.5 MB per core Level 3 (shared cache).

All three processors will have a 130W TDP, quite similar to the original six-core Gulftown based Core i7 980X. We had hoped to see a lower TDP with the original Sandy Bridge processors being so energy efficient.

Quad-channel memory

One of the hip features of the X79 / SBE platform is quad-channel memory. Though nothing has been as rock solid as Intel's 64-bit memory controllers a lot certainly happened. Over the space of three years we went from dual-channel towards triple-channel on X58 (Gulftown), then back to dual-channel with the Sandy Bridge architecture and now with Sandy Bridge-E we see quad-channel memory support. Regardless of what you think about it, progress is obviously always good.

Admittedly, the Intel memory controller, whatever platform you choose, is grand. Sandy Bridge and its dual-channel controller still hauls ass even compared to quad-channel, make no mistake there. At launch quad-channel 1600 MHz low-voltage DDR3 is supported out of the box, and that means an increase from 25.6 GB/s to 51.2 GB/s of available memory bandwidth. That's fast enough to drive a mid-range graphics card ported through system memory fairly well, well if we exclude latency of course.

Quad-channel is going to be crazy stuff, crazy numbers is what you'll see. What the effect will be on real-world performance, well yes... that's trivial at best.

More PCIe lanes

The one thing that people grumble about the most with P67/Z68 is the relatively small number of available PCIe lanes (16) for graphics cards. If you are working a setup with two or more graphics cards (SLI/Crossfire), the PCIe bandwidth is limited at x8:x8.
Here again the performance difference is trivial as running today's fastest cards barely utilizes all that bandwidth, but two x16 and then room for another x8 obviously is much better.

Sandy Bridge-E has a nice 40 lanes available. You can split them up in a variety of combinations, two x16 links with one x8 link, one x16 link and three x8 links, or one x16 link, two x8 links, and two x4 links. So this will be one concern less, though I betcha some of you would like to see three x16 as an option.

PCIe gen 3.0

What should be a prominent feature of the X79 chipset update is the inclusion of PCI Express Gen 3. In a nutshell, PCI Express Gen 3 provides a 2X faster transfer rate than the previous generation, this delivers capabilities for next generation extreme gaming solutions.

Right now we still dispute the fact that PCIe Gen 3 is working properly, we hear the same thing from several manufacturers. With no Gen 3 video cards at hand it is however impossible to test and check. If it doesn't work then it might get fixed/enabled with future BIOS updates or... Intel might have scrapped it from the feature list and is bringing it as a feature to Ivy Bridge. For now, however, this remains unconfirmed.

Regardless, we love to explain stuff; PCI Express Gen 3 has twice the available bandwidth, 32GB/s, improved efficiency and compatibility and as such it will offer better performance for current and next gen PCI Express cards. Going from PCIe Gen 2 to Gen 3 doubles the bandwidth available to the add-on cards installed, from 500MB/s per lane to 1GB/s per lane.

So a Gen 3 PCI Express x16 slot is capable of offering 16GB/s (or 128Gbit/s) of bandwidth in each direction. That results in 32GB/sec bi-directional bandwidth.

Again, the big problem is that to date there really is nothing here in the lab we can use to test these new slots. You need proper compatible hardware, like this platform, but also a graphics card or say PCIe SSD supporting the new standard.

LGA 2011

It is a little unfortunate that once again we see a new socket with this processor series. Over the last three years we left LGA 775 then started with LGA 1366, then moved to LGA 1156, with Sandy Bridge we moved to LGA 1155 and now we have to harbor the processor in socket LGA 2011.

We know, it's unfortunate, but with a changed architecture and features like the quad-channel memory controller, the lack of an embedded graphics unit and the massive update towards 40 PCIe lanes the entire dynamic changed. So ever since 2008 that's four different CPU sockets in the consumer market.

It's not a weird move to make, but for those on LGA 1155 hoping to upgrade to Sandy Bridge-E on the same motherboard, well it's not a possibility.

So yes, this means that for a Sandy Bridge-E processor you'll need to purchase an accompanying motherboard based on the X79 chipset. Not just that though, the cooler mounting is completely different as well, you'll need to seek a new mounting bracket for your cooler, or purchase an LGA 2011 compatible cooler.

The X79 chipset

Sandy Bridge-E needs a new accompanying chipset, X79 is what it's called. For those that are wondering, the internal codename for this chipset is Patsburg. Compared to X58 with a Gulftown processor there are obviously significant changes, since the Northbridge is housed inside the actual processor these days. That means that Sandy Bridge-E will connect directly to the X79 Express chipset through the DMI interconnect.
X79 Express chipset has been the topic of much discussion over the months as specs simply did not seem to finalize. Fact remains that is seems the chipset has been downgraded. Two of the changes might explain what we told you earlier, we think the PCI Express 3.0 storage uplink to the CPU was canceled out and Intel decided to cut out four SATA/SAS 6Gbps ports. And that brings us to a chipset that resembles P67 very much.
In the end you will only two SATA 6 Gb/s ports and four SATA 3 Gb/s ports supported natively by the chipset. So that is six in total for which you may configure RAID 0, 1, 5, 10 if that pleases you.
Motherboard manufacturers can, and likely will add Marvell, ASmedia and JMicron controllers to get that number up as for the most high-end chipset this seems a little too 'mainstream'.
USB ports then; this is just weird, the chipset only supports USB 2.0, not 3.0. A choice we do not understand for Intel's best offering anno 2011. You get 14 ports made available to you. USB 3.0 support once again will need to come from 3rd party controllers with extra core logic and thus overall costs mounted onto the motherboard.
Overclocking with Sandy Bridge-E
Good news for Sandy Bridge-E based platforms is overclockability. The original Sandy Bridge processors at the default baseclock (BLCK) were rather horrible to overclock. It has a lot to do with how the processor deals with the embedded graphics subsystem. If you were lucky you'd be able to increase the baseclock maybe 5 to 10 MHz multiplied at best. This is why the K and now X model processors have been introduced, easy overclocking by increasing the multiplier up-to a multiplier of 57.
This feature of course remains the same for Sandy Bridge-E with the X (Extreme) and K models. However, you should be able to overclock on the baseclock a little better now as well thanks to a new buffer chip that allows for 33 MHz increments.
Meanwhile we'll all still overclock based on the multiplier as it is 10x more easy and efficient to do so. We have limited overclockability as we are using an engineering sample motherboard that is not yet finalized. But even with that in mind it did not stop us from trying. We'll show you the overclocked results throughout the article. Regardless, the results will be flabbergasting.