Archive Home arrow Reviews: arrow Processors arrow Intel Core i7-3820 Extreme Edition CPU
Intel Core i7-3820 Extreme Edition CPU E-mail
Reviews - Featured Reviews: Processors
Written by Hank Tolman   
Monday, 05 March 2012
Table of Contents: Page Index
Intel Core i7-3820 Extreme Edition CPU
Features and Specifications
Sandy Bridge Extreme Architecture
Processor Testing Methodology
SiSoft Sandra Memory Bandwidth
AIDA64 Extreme Edition Tests
PCMark Vantage Tests
CINEBENCH R11.5 Benchmarks
CPU-Dependent 3D Gaming
PassMark PerformanceTest
Media Encoding Benchmarks
SPECviewperf 11 Tests
SPECapc Lightwave
Blender and POV-Ray
Core i7-3820 Overclocking
Sandy Bridge Extreme Final Thoughts
Intel Core i7-3820 Conclusion

Core i7-3820 Overclocking

I have to tell you, without the K or the X moniker at the end of the i7-3820, I was initially very skeptical of its overclocking ability. Sandy Bridge doesn't have the greatest track record in my mind with its ability to easily overclock. For the most part, you are limited to overclocking just the turbo boost. I was pleasantly surprised by what I found, however.

To get started, let's get into some background on Sandy Bridge overclocking. It's important to realize that, for the most part, Sandy Bridge CPUs are locked at their base clock speeds. Any Sandy Bridge CPU that supports Turbo Boost is partially unlocked simply due to the fact that they support Turbo Boost. Turbo Boost in itself is an overclock, boosting the base clock up to higher frequencies. All Turbo Boost enabled Sandy Bridge GPUs can be overclocked to run 400MHz higher than their base Turbo Frequencies. K and X series CPUs have a limited unlocked Turbo Boost and fully unlocked memory, power, and graphics capabilities. Obviously, graphics overclocking isn't something that comes into play on the Sandy Bridge-E CPUs.

i7-3820_CPU-Z.png

To explain this further, I'll talk specifically about the Core i5-2500 and i5-2500K processors. The i5-2500 has a base frequency of 3.3GHz and a Turbo Boost Frequency of 3.7GHz with 1 active core, 3.6GHz with 2 active cores, 3.5GHz with 3 active cores, and 3.4GHz with 4 active cores. With the limited unlock capabilities of this CPU, you could boost each of those Turbo frequencies by an additional 400MHz, making the maximum overclock 4.1GHz if only 1 core is active. The i5-2500K is virtually the same, except for the fact that the unlocked K-series CPU has a limited unlocked modifier that lets it go above that 400MHz threshold. It's still limited, however, so that the max overclock you could potentially achieve is 5.7GHz with 1 active core.

While the two, higher end Sandy Bridge-E CPUs are both X or K-series CPUs and are thus unlocked, the i7-3820 is not. This makes it potentially more difficult to overclock than the other Extreme Edition CPUs. Since the i7-3820 uses Turbo Boost and has a max Turbo of 3.9GHz, it reasons that you should be able to overclock to 4.3GHz by just using the standard, limited multiplier adjustments available with any Turbo Boost enabled Sandy Bridge CPU. Remember that the 4.3GHz mark would only be for a single active core. With all four cores running, the best you should be able to see is 4.0GHz. Pretty boring stuff for an Extreme Edition CPU, right?

Luckily for us, Sandy Bridge-E made some other changes that affect overclocking. While normal Sandy Bridge platforms use a bclk of 100MHz, the Sandy Bridge Extreme can use a bclk of 100MHz, 125MHz, 166MHz, or 250MHz. Just crunching the numbers, if that 4x the bclk ratio is in effect, then with the multiplier at 43, as it was for the single core turbo overclock with the 100MHz bclk, we are looking at a potential overclock of 5.375GHz with a bclk of 125MHz, 7.138GHz at a 166MHz bclk, and 10.75GHz at a 250MHz bclk. Obviously, pushing the bclk to 250MHz, or even 166MHz, is really out of the question. Even using the base clock as the multiplier at 3.6GHz, you're trying for a 5.9GHz overclock with the 166MHz bclk. But 125MHz bclk is right up our alley.

Just by pushing the bclk up to 125MHz, you are already looking at a base overclock to 4.5GHz. That's quite respectable, considering that would run on all 4 cores as opposed to the standard max of 4.3GHz on a single active core. To get all I can out of the i7-3820, I'll probably need to change some of the other settings besides just the blck frequency. I used the ASUS Rampage IV Formula motherboard for this overclock. To find out more about the specific settings I tweaked, watch out for my review of that motherboard. I'll tell you just what I did to get to 4.75GHz on the i7-3820.

i7-3820_CPU-Z_OC.png

The X79 chipset brings a separate base clock back into the overclocking world, so this time-honored mechanism is again available. The CPU itself adds a new twist: in addition to increasing the voltage to the chip to support higher speeds, you can now increase the sustained maximum and burst maximum current draw as well.

3960X Stock

3960X OC

AIDA64 Queen

1.0

1.27

AIDA64 Photoworxx

1.0

1.20

AIDA64 AES

1.0

1.10

AIDA64 ZLIB

1.0

1.26

AIDA64 Hash

1.0

1.26

CINEBENCH Single Core

1.0

1.31

CINEBENCH Multi Core

1.0

1.23

Passmark CPU Marks

1.0

1.31

PCMark Vantage TV/Movies

1.0

1.19

PCMArk Vantage Gaming

1.0

1.20

PCMark Vantage Music

1.0

1.21

Street Fighter IV

1.0

1.19

Handbrake 0.95

1.0

1.21

x264HD Run 1

1.0

1.32

x264HD Run 2

1.0

1.32

x264HD Run 3

1.0

1.27

x264HD Run 4

1.0

1.25

SPECviewperf Lightwave

1.0

1.27

SPECviewperf Maya

1.0

1.27

SPECviewperf TCVIS

1.0

1.29

SPECapc Lightwave Interactive

1.0

1.19

SPECapc Lightwave Multitasking

1.0

1.20

SPECapc Lightwave Rendering

1.0

1.30

Blender/Icetest

1.0

1.40

POV-Ray

1.0

1.09

Average Performance Improvement

24%

A nearly 32% increase in base clock speed improved performance on average by 24% during our tests. I'd call that very successful for a locked CPU. I'd bet with a little more tuning we could probably see 5GHz on the i7-3820 without many issues. Remember that each component is different and each individual CPU or motherboard will result in different overclocking speeds and capabilities.



 

Comments 

 
# Sweet spot?realneil 2012-03-06 09:55
I wonder if this will be the affordable sweet spot for many of us? The lower price is compelling and the performance is very good too. I can't see quitting my i7-2600K system for this one yet, but it looks to be a good choice for future consideration.
Report Comment
 
 
# Uhh.. this isn't an Extreme Editionbcmac401 2012-03-06 10:07
That would be the 3960X. This is the baseline LGA2011 Core i7.
Report Comment
 
 
# RE: Uhh.. this isn't an Extreme Editionchristopher hardin 2013-07-02 08:03
oh he means sandy bridge extreme. i was screaming at my screen for a second too...
Report Comment
 
 
# From a Multi-GPU gaming rig builder's perspectiveLuay 2012-03-07 05:18
The difference between the i7 3820 and the i5 2550k in gaming performance is not worth the extra money spent on the CPU, motherboard and quad channel RAM.
For two CF/SLI GPUs we have P67 motherboards in the $120~$180 range.
For tri-fire/SLI or more we have NF200 equipped P8P67 WS Revolution and Rampage boards that sell for the same price of a low-end LGA 2011 motherboard. This is a hard sell either because it's not good enough or LGA 1155 is just too good.
Report Comment
 
 
# Love Mine.Enigma8750 2012-03-20 08:21
Coming from AMD 890 board to this motherboard was like night and day. My Benchmark 06 is 29080 at 4.5 ghz. I know I can get more but I want a nice stable system with no errors. The Performance of the CPU and the Two 5770's Crossfired is amazing. I am only using Corsair 1600 memory but this computer is a F1 Race car. My old 5xxx Video cards have never Breathed so well. I can only imagine what a couple of 7850's would look like. I am amazed at this CHIP and I bought my ASRock Extreme 9 board for this chip at Christmas, knowing that it would be a killer chip at an excellent price. it is. I am very very happy with mine and I love it.
Report Comment
 
 
# Happy to keep what I have!DB62 2012-03-20 21:40
Ya, I know it's way overpriced, but my system, with a 990X, a GTX580 Lightning, 4 raid-0 RE4's, and 1-Intel 510 SSD, serves every need I have, and does it fast, without a problem. Plus, it's an overclocking champ.
Report Comment
 
 
# ewfxcc 2012-03-31 22:28
don't understand what comparision demonstarte when all cpus are running different amount of ram.3xxx with 16gb and few ones only on 4gb.my athlon x2 was doing 44fps on 2gb and 122fps on 4gb on specviewperf maya with all other component same ,resolution, threads etc everything same. as such benchmark is 100% fake to me. yes 3xxx needs 4 ram for quad channel but 4 ram can be used in dual channel too. so why not all cpus running 16gb(for quad and dual both) and 12gb(for triple channel).
simply seems intel sponsered benchmark to fakely demonstrate 3xxx is best processor
Report Comment
 
 
# RE: ewfDavid Ramsey 2012-03-31 23:07
Since none of these benchmarks are memory-constrained, the amount of memory (past 2G or so) is irrelevant.
Report Comment
 
 
# RE: RE: ewfxcc 2012-04-01 06:28
but whats problem installing same amount of ram on all. also speed of ram r different
Report Comment
 
 
# Great investmentGlock10mm 2012-04-14 22:50
Just picked up the 3820 and an X79 SABERTOOTH.Great upgrade from my AMD 980 & ASUS Crosshair board. Using my same 1600 ram(which would never run @ 1600 on my old board) and crossfired 6870's. Works great and and really only cost about $75 more for the setup than the 2600k setup(buying a high end 1155 board). Running @ 4.625 and very stable. If I had already owned an 2600k setup, it would not be worth the money for the minimal gain. Coming from an 2 year old board and going to Intel for the first time in 10 years, it seemed to make sense to purchase the newest socket board.
Report Comment
 
 
# 1.624v ,ReallyJohn Elmore 2012-05-12 06:52
Running a i7-3820 at 4750gigs at a whopping 1.624v on a lower end CPU water cooler Corsair H60,I would like to know what your temperatures were reading.I find it hard to believe that it did not shut down with that kind of voltage running though it ,when intel says the safest voltage is 1.350v and not to run it over 67c.I know with just a Corsair H-60 you would be running way over 67c.Unless it was reading the voltage wrong.I have a i7-3820 on a ASRock X79 ExeTreme 4 and I can run 4750gigs at 1.304v and my tempertures run at 65c-62c-64c-60c running Prime95,on AIR a $35 Coolermaster 212 EVO.If them H-60's run that good I will have to get me one ,but all the reviews I have seen puts them around 3c to 5c cooler then what I am running.I would really like to see your tempertures at 1.624v at 4750gigs.
Report Comment
 
 
# Egg CookerRich 2013-03-15 12:37
He's trying to turn that proc into an egg cooker!!
Report Comment
 
 
# 1.41V @ 45CStick 2013-05-10 23:36
I'm at 5 Ghz with DDR 1600, started at 1333 on MSI Big Bang Xpower II board... But I'm using the Antec 25 (Kuhler H2O cooler).
Report Comment
 

Comments have been disabled by the administrator.

Search Benchmark Reviews
QNAP Network Storage Servers

Follow Benchmark Reviews on FacebookReceive Tweets from Benchmark Reviews on Twitter