Review Index:
Feedback

Intel Sandy Bridge-E Review - Core i7-3960X and X79 Chipset Tested

Author: Ryan Shrout
Subject: Processors
Manufacturer: Intel

Overclocking

Overclocking with the new Sandy Bridge-E processors is almost exactly the same as it is with current Sandy Bridge parts- with just a couple of tweaks that increase OC potential. 

View Full Size

As we mentioned on the previous page, the new lowest multiplier for the CPU is 12x, lowering the idle speed to 1200 MHz compared to the 1600 MHz on the previous generation.

View Full Size

With only a couple of threads running, the Core i7-3960X will spike as high as 3.9 GHz using the standard Turbo Boost technology which provides a noticeable increase in performance over the 3.3 GHz base clock.

View Full Size

With all cores loaded though, the highest clock speed provided by this Extreme Edition CPU is 3.6 GHz. 

View Full Size

This is a screenshot from the BIOS of ASUS' latest UEFI for the X79 platforms.  You can see that the Base Clock (BCLK) starts at 100 MHz and the Turbo ratio can be adjusted for all cores (giving us a consistently clocked part) or for each core (performing more like the Intel default actions).  This is exactly the way current Sandy Bridge overclocking works.  

What is new is the addition of the "CPU Strap" - though it is called different things in different motherboard BIOSes.  This is essentially a new multiplier added to the Sandy Bridge-E processor that allows the BCLK to be set higher than it could be on Sandy Bridge.  If you have overclocked with SNB previously, you know that pushing beyond the 100 MHz BCLK was very difficult: if you could get 107-108 MHz you were doing very well.  With the CPU Strap, you can now actually run at higher BCLK settings.

Setting the CPU Strap to 1.25x or 125 MHz will actually start the CPU at 125 MHz BCLK and then let you adjust from there if you want.  You will still only get the minimal stable adjustments (7-8 MHz) but you'll then be running at 130+ MHz BCLK and when coupled with your multiplier adjustments, could lead to your best performing system.

The CPU Strap keeps the other multipliers in check as well - you don't have to worry about increasing the speed of your memory or PCI Express clocks when using the strap settings.  That was really the bottleneck on current Sandy Bridge systems, and Intel has helped resolve this with Sandy Bridge-E.  Chances are good though that you'll still be able to hit a really good overclock using JUST the multipliers if you have the Core i7-3960X or the Core i7-3930K as they are fully unlocked.  The CPU strap could be much more interesting with the "partially unlocked" Core i7-3820 when it arrives.

View Full Size

If you happen to purchase an Intel DX79SI they also permit overclocking to higher degree than you might, at first, have guessed both in the BIOS and with a highly competent software overclocking suite called XTune.  

View Full Size

Using the Core i7-3960X and our Intel sealed loop water cooler I was able to hit a clock speed of 4.7 GHz, stable, on all 6-cores.  For those highly threaded applications that would normally be capped at 3.6 GHz, that is a 1.1 GHz overclock (just over 30%) - very nice!!

View Full Size

You can see our POV-Ray benchmark result running under these settings is incredibly high as well - compared to the score of 7506 pps at default speeds. 

November 14, 2011 | 03:35 AM - Posted by Anonymous (not verified)

Main and only reason for disabling cores in design is that in production process of chips(for example Xeon processors) they may encounter defects that with this mechanism tolerates these situations.

November 14, 2011 | 03:40 AM - Posted by Ryan Shrout

Defects might be the wrong word here. But they usually do it to allow the other cores to clock higher, important on a consumer product. Less important on a server environment.

November 14, 2011 | 08:12 AM - Posted by Anonymous (not verified)

The main reason i understood what that they wanted to stay within the 130W TDP envelop, plus less cores means less heat, means more OC, means more FPS.

Unless you fall in the small group of users that do programs like video encoding.

November 14, 2011 | 10:31 AM - Posted by Anonymous (not verified)

They could use this transistors for other matters,for example for cache modules, but they don't use these space for anything.With one difference This architecture is similar to Celeron processors in previous Intel designs. In this arrangement cores are deactivated instead of caches modules.Cores is disabled instead of CPU When any of them defected in production process in the factory.

November 14, 2011 | 03:53 AM - Posted by Dave Bruce (not verified)

When will we get some costs and build specs? Also what are the supply lines like will we have to wait awhile before wholesalers have stocks? Great Review well done.

November 14, 2011 | 07:49 AM - Posted by Imperfectlink

Fell a little flat with the render tests. Could you please include something a little more contemporary eg. Cinebench 11.5 please? After all, this is going to be one of the target demographics for the processor.

Edit: Especially need an overclocked CB score. That's what people will be doing with them.

November 14, 2011 | 08:28 AM - Posted by Ryan Shrout

CB 11.5 scales VERY well, much like POV-Ray, and we provided an overclocked POV-Ray result, so you should be able to use that one.

November 14, 2011 | 09:26 AM - Posted by perfectshot (not verified)

Awesome review Ryan! The performance per $ still makes the i7 2600K seem like the best choice if on a budget.

Can't wait to see what the leader board looks like in Q1 2012.

;-)

November 14, 2011 | 12:48 PM - Posted by Ryan Shrout

Yeah, I definitely wouldn't consider this a budget part at all, even the Core i7-3930K...

November 14, 2011 | 11:26 AM - Posted by Mt2e

I just feel that if you were to have the workloads that sb-e provides benifits for wouldn't you just get a Xeon based system.

November 14, 2011 | 12:49 PM - Posted by Ryan Shrout

Not if you are a small biz or pro-sumer looking to save money.

November 14, 2011 | 12:48 PM - Posted by Sihastru

I realize that this 3960X is top dog when it comes to desktop CPUs, but I can't help it to feel a bit sad when I know there's two extra cores with an extra 5MB of cache disabled, just sitting there, doing nothing.

And it's not like it's just a certain feature that's disabled, it's two fully hyperthreaded cores! That's like a really good extra dual core CPU that's gone dark, something like an unlocked Sandy Bridge 2100K (non existant, but you get the point). It takes "dark silicon" to the next level.

Is this to preserve a certain clockspeed - power envelope ratio or is this just because there's virtually no competition in this segment anymore? Is it that much cheaper to have just one die for desktop/worstation/server?

Do I get to blame AMD for ruining my life all over again? (hint: it's a joke)

November 16, 2011 | 04:57 PM - Posted by Ryan Shrout

"Is this to preserve a certain clockspeed - power envelope ratio.."

You are correct right here - those two cores aren't doing "nothing"; what they are doing is allowing the Core i7-3960X to clock as high as it is.

I still agree with you though - I wish Intel had released an 8-core version with a lower top speed so we had two options at this insane price point.

November 14, 2011 | 02:08 PM - Posted by Mt2e

Yer right Ryan about the cost when u think about it.

Ryan do you think SB-E will minimize multi-GPU microstutter? because its basically sb+2 I dont think it will but I dont know how the increased system bandwidth will minimize "jitter"

November 14, 2011 | 02:38 PM - Posted by Anonymous (not verified)

How are the single core on Blender better?? The new sb-e is the fastest single thread on the chart with 76.13 sec. Were you looking at it backwards. You may also look into using the new cycles render instead of the old Blender, as it will be the new standard in Blender 2.62 comming December.

-Sonic

November 14, 2011 | 04:57 PM - Posted by Ryan Shrout

You are correct, I was reading those results backwards. Thanks, fixed!

November 14, 2011 | 04:51 PM - Posted by Anonymous (not verified)

this CPU is a BIG FAIL!!!

$1000 and its single core performance is slower than 2600K !

Why are Review websites not slamming this CPU?

November 14, 2011 | 05:01 PM - Posted by Ryan Shrout

The same reason we didn't "slam" $1000 CPUs for the decade they have continued to be released. They aren't meant for single core workloads and excel really only in the outlier cases of heavy threaded workloads and the like.

No, this CPU isn't for most, it isn't even likely for MANY people, but the fact that it is there is good for the market to be pushed forward.

I don't remember anyone complaining when the Core i7-980X launched...?

November 14, 2011 | 04:56 PM - Posted by Anonymous (not verified)

$1000 Intel CPU FAIL

hardocp link

November 16, 2011 | 04:22 PM - Posted by AParsh335i (not verified)

Troll...

November 14, 2011 | 05:37 PM - Posted by Anonymous (not verified)

Why in the world would anyone praise this cpu. It's a mediocre step forward from the 2600k, and with Ivy on the way in the first half of next year, a complete waste of money.

November 14, 2011 | 07:05 PM - Posted by Ryan Shrout

I am afraid you are going to be more disappointed in the CPU performance of Ivy Bridge than Sandy Bridge-E...

November 15, 2011 | 08:22 PM - Posted by mtrush (not verified)

why? ivy bridge will be more cost effective for intel and us.
possibly less power and more cores. god forbid faster cores.

November 16, 2011 | 05:44 PM - Posted by Ryan Shrout

Because the CPU portions of Ivy Bridge compared Sandy Bridge are likely only going to be about 5-10% better.

November 14, 2011 | 06:33 PM - Posted by mtrush (not verified)

ya i'd wait for ivy-bridge and ddr4 2012

November 14, 2011 | 09:58 PM - Posted by drbaltazar (not verified)

wrong amd cpu to put against the i7 e3960x,you should be revisiting just the e3960x vs the opteron 6282se,that is the same priced cpu to go against the 3960,price for price the
3820 will be a better counter part to the 8150 or the

November 15, 2011 | 12:56 AM - Posted by DJBRUCE

If I want a top end gaming pc should I go for the SBE 3960 with the ASUS extreme IV m/b with twin 580 in SLI or am I just wasting my money:(

November 26, 2011 | 09:24 PM - Posted by Kaosuonline (not verified)

The twin 580's sound awesome. I'd stick with a Sandy Bridge 2500K and an ASUS P867WS Revolution MoBo. You are sure not going to bottleneck with that (if you are going with just one card then go with the P8P67 PRO. Two 580's are going to draw a lot of power. 850W plus (preferably plus).

November 15, 2011 | 07:31 AM - Posted by Anonymous (not verified)

I think Ryan did a good job explaining the subtle differences between the SB and SB-E. Moreover, with AMD's lackluster Bulldozer turnout and SB-Original not offering more than 4 cores, this CPU is now the premier CPU on the consumer planet. Look, if you want TOP-end power for a while- you're not going to find it anywhere else ...

... and they're going to charge it- because they can.

November 15, 2011 | 08:12 AM - Posted by t3ngu (not verified)

Another crappy comparison.
You compare CPU's reaching 1000 euros in price (intel) vs a mere 200 euros of the bulldozer (amd).

Compare two same priced cpu's and its more of a test than this complete waste of time

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Lines and paragraphs break automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <blockquote><p><br>
  • Web page addresses and e-mail addresses turn into links automatically.

More information about formatting options

By submitting this form, you accept the Mollom privacy policy.