Intel Core i7 3960X (Sandy Bridge E) Review: Keeping the High End Alive
by Anand Lal Shimpi on November 14, 2011 3:01 AM EST- Posted in
- CPUs
- Intel
- Core i7
- Sandy Bridge
- Sandy Bridge E
If you look carefully enough, you may notice that things are changing. It first became apparent shortly after the release of Nehalem. Intel bifurcated the performance desktop space by embracing a two-socket strategy, something we'd never seen from Intel and only once from AMD in the early Athlon 64 days (Socket-940 and Socket-754).
LGA-1366 came first, but by the time LGA-1156 arrived a year later it no longer made sense to recommend Intel's high-end Nehalem platform. Lynnfield was nearly as fast and the entire platform was more affordable.
When Sandy Bridge launched earlier this year, all we got was the mainstream desktop version. No one complained because it was fast enough, but we all knew an ultra high-end desktop part was in the works. A true successor to Nehalem's LGA-1366 platform for those who waited all this time.
Left to right: Sandy Bridge E, Gulftown, Sandy Bridge
After some delays, Sandy Bridge E is finally here. The platform is actually pretty simple to talk about. There's a new socket: LGA-2011, a new chipset Intel's X79 and of course the Sandy Bridge E CPU itself. We'll start at the CPU.
LGA-2011, the new socket
For the desktop, Sandy Bridge E is only available in 6-core configurations at launch. Early next year we'll see a quad-core version. I mention the desktop qualification because Sandy Bridge E is really a die harvested Sandy Bridge EP, Intel's next generation Xeon part:
Sandy Bridge E die
If you look carefully at the die shot above, you'll notice that there are actually eight Sandy Bridge cores. The Xeon version will have all eight enabled, but the last two are fused off for SNB-E. The 32nm die is absolutely gigantic by desktop standards, measuring 20.8 mm x 20.9 mm (~435mm^2) Sandy Bridge E is bigger than most GPUs. It also has a ridiculous number of transistors: 2.27 billion.
Around a quarter of the die is dedicated just to the chip's massive L3 cache. Each cache slice has increased in size compared to Sandy Bridge. Instead of 2MB, Sandy Bridge E boasts 2.5MB cache slices. In its Xeon configuration that works out to 20MB of L3 cache, but for desktops it's only 15MB. That's just 1MB shy of how much system memory my old upgraded 386-SX/20 had.
| CPU Specification Comparison | ||||||||
| CPU | Manufacturing Process | Cores | Transistor Count | Die Size | ||||
| AMD Bulldozer 8C | 32nm | 8 | 1.2B* | 315mm2 | ||||
| AMD Thuban 6C | 45nm | 6 | 904M | 346mm2 | ||||
| AMD Deneb 4C | 45nm | 4 | 758M | 258mm2 | ||||
| Intel Gulftown 6C | 32nm | 6 | 1.17B | 240mm2 | ||||
| Intel Sandy Bridge E (6C) | 32nm | 6 | 2.27B | 435mm2 | ||||
| Intel Nehalem/Bloomfield 4C | 45nm | 4 | 731M | 263mm2 | ||||
| Intel Sandy Bridge 4C | 32nm | 4 | 995M | 216mm2 | ||||
| Intel Lynnfield 4C | 45nm | 4 | 774M | 296mm2 | ||||
| Intel Clarkdale 2C | 32nm | 2 | 384M | 81mm2 | ||||
| Intel Sandy Bridge 2C (GT1) | 32nm | 2 | 504M | 131mm2 | ||||
| Intel Sandy Bridge 2C (GT2) | 32nm | 2 | 624M | 149mm2 | ||||
Update: AMD originally told us Bulldozer was a 2B transistor chip. It has since told us that the 8C Bulldozer is actually 1.2B transistors. The die size is still accurate at 315mm2.
At the core level, Sandy Bridge E is no different than Sandy Bridge. It doesn't clock any higher, L1/L2 caches remain unchanged and per-core performance is identical to what Intel launched earlier this year.
The Lineup
| Processor | Core Clock | Cores / Threads | L3 Cache | Max Turbo | Max Overclock Multiplier | TDP | Price |
| Intel Core i7 3960X | 3.3GHz | 6 / 12 | 15MB | 3.9GHz | 57x | 130W | $990 |
| Intel Core i7 3930K | 3.2GHz | 6 / 12 | 12MB | 3.8GHz | 57x | 130W | $555 |
| Intel Core i7 3820 | 3.6GHz | 4 / 8 | 10MB | 3.9GHz | 43x | 130W | TBD |
| Intel Core i7 2700K | 3.5GHz | 4 / 8 | 8MB | 3.9GHz | 57x | 95W | $332 |
| Intel Core i7 2600K | 3.4GHz | 4 / 8 | 8MB | 3.8GHz | 57x | 95W | $317 |
| Intel Core i7 2600 | 3.4GHz | 4 / 8 | 8MB | 3.8GHz | 42x | 95W | $294 |
| Intel Core i5 2500K | 3.3GHz | 4 / 4 | 6MB | 3.7GHz | 57x | 95W | $216 |
| Intel Core i5 2500 | 3.3GHz | 4 / 4 | 6MB | 3.7GHz | 41x | 95W | $205 |
Those of you buying today only have two options: the Core i7-3960X and the Core i7-3930K. Both have six fully unlocked cores, but the 3960X gives you a 15MB L3 cache vs. 12MB with the 3930K. You pay handsomely for that extra 3MB of L3. The 3960X goes for $990 in 1K unit quantities, while the 3930K sells for $555.
The 3960X has the same 3.9GHz max turbo frequency as the Core i7 2700K, that's with 1 - 2 cores active. With 5 - 6 cores active the max turbo drops to a respectable 3.6GHz. Unlike the old days of many vs. few core CPUs, there are no tradeoffs for performance when you buy a SNB-E. Thanks to power gating and turbo, you get pretty much the fastest possible clock speeds regardless of workload.
Early next year we'll see a Core i7 3820, priced around $300, with only 4 cores and a 10MB L3. The 3820 will only be partially unlocked (max OC multiplier = 4 bins above max turbo).
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xpclient - Monday, November 14, 2011 - link
I read Intel is not going to release AHCI/SATA/Matrix RAID drivers for 32-bit Windows XP for X79. Why??? Without AHCI, performance is going not going to be optimal. For those that dual boot with Windows 7, this means changing the settings from AHCI to IDE every time you boot into XP.Rick83 - Monday, November 14, 2011 - link
And I heard that USB 3 had no drivers for my Win95 D either!B3an - Monday, November 14, 2011 - link
Because no one in there right mind would buy this high-end platform then use a decade old POS operating system. Waste of Intels time to support it and XP needs to die already.XP will take little advantage of SSD's or even new HDD's properly, some drives wont even work at all on it, and it lacks the same level of support and performance for CPU features and multiple cores that Win7 has. If you really need to run some old software just use XP mode in Win 7 or use VM software.
xpclient - Monday, November 14, 2011 - link
Are you not aware of multi-core benchmarks? http://www.infoworld.com/t/platforms/generation-ga... Windows 7 does not perform faster than XP until you reach eight cores or higher.Peskarik - Monday, November 14, 2011 - link
"Just as with previous architectures, installing fewer DIMMs is possible, it simply reduces the peak available memory bandwidth."So, I have:
Asus P8Z68-V Pro/Gen3 motherboard
Intel Core i7 2600K
Corsair Vengeance Red, 2x4GB, DDR3-1600, CL9@1.5V
When I am in BIOS the memory is set to 1333Mhz, and I had to manually set it to 1600, though I am not sure whether it actually runs at this speed (how can I check?).
Does the above sentence from the article mean that with 8GB RAM I do not have full memory bandwidth and that if I install 16GB RAM (I have 4 slots) then I have full 1600Mhz automatically?
kr1s69 - Monday, November 14, 2011 - link
Sandy Bridge E is quad channel and so needs 4 DIMM's to obtain the peak bandwidth. Your Sandy Bridge system is dual channel and so you need 2 DIMM's to obtain the peak bandwidth. This is what you currently have installed, so no need to worry.The statement you quoted is basically saying this motherboard would boot with less than 4 DIMM's installed, that is all.
Sandy Bridge defaults to 1333Mhz but you can change this in the BIOS to 1600Mhz as you have done. You can download CPU-Z to confirm what speed your RAM is set to.
piroroadkill - Monday, November 14, 2011 - link
Set the O/C Profile to X.M.P.This uses the eXtreme Memory Profile provided by your RAM. Basically, standard SPD ratings don't go as high as 1600. XMP is required for this, it's a custom Intel extension to SPD.
piroroadkill - Monday, November 14, 2011 - link
Although it's supposed to work, in my experience I had to set my RAM to DDR3-1600 anyway. Ho hum.lukarak - Monday, November 14, 2011 - link
This is not a great update. I wonder if 2011 will be the socket for ivy bridge E. If that's the case, it could be a good buy for somebody transitioning from an older system.dlitem - Monday, November 14, 2011 - link
There were some rumors / news circulating earlier that VT-d is bugged. Is that actually the case? SB-E is The workstation platform and losing VT-d is kind of a shame, as there actually are people who might have benefited from it.Also, a lot of us are still running our trusty 3 year old Quad-Bloomfields that have served us so well, so including one LGA1366 Quad-core would have be a really nice thing.