Ivy Bridge Overclocked and Tested Again
It wasn't horribly long ago that breaking 4GHz with a CPU was left for those with 'Extreme' Cooling. In order to push past that 4GHz barrier you needed to run a CPU cooling solution that could bring your processor below the ambient temperature. Whether it was chilled water, Phase change cooling, or something much more extreme like dice (dry ice) or LN2 (liquid Nitrogen) would determine just how far you could push your processor. Unfortunately, cooling like that isn't as readily available as a custom water cooling loop, or a top tier air cooler like the Corsair A70 cooler that I've been using on our motherboard testing over the past year or so. If you were running sub-ambient cooling you know the draw backs to it all to well. Dice and LN2 cant be used as a daily solution since you have to constantly refill the pot. Chilled water and phase change cooling both produce condensation on the motherboard and processor area and increase your chances of water shorting out your system. I'm not saying that it can't be done, as many have done it, but these aren't for the average overclocker.
Until recent years, when it comes to Intel processors, just about all of the overclocking was done with the Bclk. Unless of course you have deep pockets and wanted to spend a grand on an Intel Extreme processor that features an unlocked multiplier. If you did have an Intel Extreme processor you could increase the processor multiplier as well as the Bclk when overclocking. This combination of Bclk and multiplier overclocking allowed for great fine tuning when overclocking. Though not everyone has a grand to drop on the extreme processors. In May of 2010 Intel released their first mainstream processors with an unlocked multiplier! The Intel Core i7 875K and the Core i5 655K Lynnfield processors were the first K-series sku's. Since then, the Intel K series sku's have become a staple in the Intel product stack. If Intel ever eliminates the K-series processors they may just have a riot on their hands.
Moving past the LGA1156 Lynnfield processors, Intel launched the LGA1155 H2 socket along with their new 'Sandy Bridge' processors. This is where overclocking became both limited, and exhilarating at the same time! If you aren't familiar with overclocking since the Intel 'Sandy Bridge' launch in January of 2011, it's been a trip. Intel all but did away with Bclk overclocking. If you were lucky, you may have been able to find a 'Sandy Bridge' processor that was able to handle a 110MHz Bclk. That's only 10% over the stock Bclk of 100MHz, more than likely you would have a chip that could handle around 105MHz Bclk. Fortunately Intel carried over the K-series sku's and brought us processors with and unlocked multiplier! The Intel Core i7 2600k and the Intel Core i5 2500k had a maximum CPU multiplier of x59. What made overclocking with Intel 'Sandy Bridge' exhilarating was the frequencies we were able to hit! Our first run at Sandy Bridge overclocking we were able to hit 4.8GHz+ on air! Until this point that was absolutely unheard of! Overclocking with the Intel 'Sandy Bridge' platform was like a fine wine, it only got better with time! Not long after the initial launch ASUS introduced a feature inside their UEFI BIOS called Internal PLL Overvoltage. The Internal PLL Overvoltage allowed us to push the Sandy Bridge processors further yet.
Now we can jump forward to today. Recently Intel launched the Intel Z77 chipset and the latest and greatest mainstream processors, aka Intel 'Ivy Bridge'. The Intel 'Ivy Bridge' processors like the Intel Core i7 3770k have a number of changes in the architecture that allow it to consume less power and run more efficient. For an in depth look at the architecture of the new Intel 'Ivy Bridge' Processors you can check out our full review here. We definitely noticed a couple of things during our testing that are worth mentioning again. The first and potentially most important to most, is that the Intel Core i7 3770K was consistently faster than the previous generation Intel Core i7 2700K. What's significant about this is that both the 2700K and the 3770K come with an out of the box clock speed of 3.5GHz. Obviously Intel made some improvements to the architecture as well as shrinking the die size to 22nm. If we look back at the power consumption page of the article we can see that the power consumption of the Intel Core i7 3770K is lower than the previous generation when we compare these two processors with comparable clock speeds.
Although the Intel Core i7 3770K uses less power, some would consider that the 3770K has an issue with temperatures. Since the launch of the third generation Intel Core i7 'Ivy Bridge' processors, it has been discovered that Intel opted to use a thermal paste to transfer heat to the integrated heat spreader. The previous generation Intel Core i7 'Sandy Bridge' processors used a little bit different technique to transfer the heat. The 'Sandy Bridge' core and the heat spreader were soldered together which is a much more effective means to transfer the heat.
A Japanese tech site, Impress PC Watch pulled their processor apart, and above we can see the TIM used on the third generation Intel 'Ivy Bridge' processors. They have also replaced the Intel TIM with a couple others and had seen a dramatic result. At idle they didn't see much in the way of improvement, under a full processor load though it was a different story. By replacing the TIM, the load temperatures dropped by 11 degrees Celsius at stock settings. They also ran the Intel Core i7 3770K at 4.6GHz and saw a drop of 20 degrees! It's not clear why Intel choose to go this route, though it doesn't look like it was the best choice for them. With my little rant being over, we can move on to the good stuff. We are going to take a look at how far we can push our Intel Core i7 3770K processor on air cooling today. We will be using a Corsair A70, which is no slouch when it comes to cooling to try and keep this beast cool under a heavy load!
The Legit Reviews Test System
Before we look at the numbers, here is a brief glance at the test systems that were used. All testing was done on a fresh install of Windows 7 Ultimate 64-bit. All benchmarks were completed on the desktop with no other software programs running.
Intel Z77 System
Intel Test Rig
|Processor||Intel Core I7 3770K||Live Pricing|
|Motherboard|| ASUS P8Z77-V Deluxe
|Memory||8gb Corsair Vengeance 1600MHz||Live Pricing|
|Hard Drive||Kingston SSDNow 96GB SSD||Live Pricing|
|Video Card||XFX Radeon HD 6950||Live Pricing|
|CPU cooler|| Corsair A70
|Chassis||None - Open Bench|
|Power Supply||Corsair TX750||Live Pricing|
ASUS P8Z77-V Deluxe System Settings
Intel Core i7 3770k 'Ivy Bridge' Overclocking
Overclocking greatly varies due to what hardware is being used and who is doing the overclocking. Always remember that no two pieces of hardware will perform the same, so our results will differ from what you might be able to get.
The Intel Core i7 3770K utilizes a Bclk of 100MHz, under full load the Intel Core i7 3770K uses a multiplier of x35 to achieve the final clock speed of 3.5GHz. Since we are using a K series processor which has an unlocked multiplier we will be able to increase the default x35 multiplier to achieve our overclock today. We can see in the above CPUz 1.60 screen shot that with the Turbo mode engaged we are cruising along at 3.9GHz. The ASUS P8Z77-V Deluxe has a couple of different methods of automatic tuning. We looked at the first in our Intel Z77 Motherboard round up just recently and found that the basic ASUS 'Auto Tune' feature brought us to a comfortable 4223MHz overclock. It was accomplished with a CPU Multiplier of x41 and a Bclk of 103MHz. This was a rock solid overclock but a little on the conservative side.
Within the ASUS AI Suite II software, there is also the option for extreme tuning. Once we engage the extreme tuning we are on our way to a fully tuned system. The extreme tuning will overclock your system based on algorithms that will take the system temperature into account. So depending on the cooling solution you use, you may see results that vary from what our system was able to achieve.
After a little bit of testing, the ASUS P8Z77-V Deluxe brought our system up to 4548.98MHz! The AI Suite II software increased the Bclk to 105.79MHz, and the CPU multiplier to x43. This is 325MHz faster than the 'Fast' tuning option that uses the predetermined settings!
Of course we weren't going to leave well enough alone, we wanted to see just how far we could push our Intel Core i7 3770k while maintaining complete system stability. In the round up we were able to to hit 4.8GHz with while the system was stable. It turns out that we weren't exactly on the ball with that. For system stability, we were running wPrime. We were able to run both tests with wPrime while our 3770k was running at 4.8GHz until we were blue in the face. Once we tried running a benchmark like x264 HD Video encoding or even 3DMark Vantage the system would either hang, or give us the infamous BSOD. Ultimately we were able to back the multiplier down by one and run our chip rock solid at 4.7GHz with a multiplier of x47.
Intel Core i7 3770k 'Ivy Bridge' Overclocking Settings
I don't often use the overclocking software that is bundled with a motherboard, but I figured why not give the ASUS AI Suite software a go. Not gonna lie, the software worked without a hitch. We were able to bring the Intel Core i7 3770k up to 4.8GHz without an issue. Granted we weren't as stable as we thought we once were, so we had to back the multiplier down to x47 and we were golden at 1.35 Volts on the CPU vCore.
The ASUS AI Suite II software allows you to tune the CPU per core, though we stuck to group tuning and increased all four core simultaneously.
We stuck our heads into the DIGI+ Power Control, we increased the CPU Load-line Calibration to Ultra High, and the CPU Current Capability to 140%. Though as I continue playing with the system as I type this, the CPU Current Capability doesn't appear to effect the system stability, as the system behind me is set to 100% and is running fine.
x264 HD Encoding
Simply put, the x264 HD Benchmark is a reproducible measure of how fast your machine can
encode a short HD-quality video clip into a high quality x264 video
file. It's nice because everyone running it will use the same video clip
and software. The video encoder (x264.exe) reports a fairly accurate
internal benchmark (in frames per second) for each pass of the video
encode and it also uses multi-core processors very efficiently. All
these factors make this an ideal benchmark to compare different
processors and systems to each other. We are using x264 HD v4.0 for this test.
This application did fairly well when run on 12 threads, as you can
see from the screen shot above. The first pass was not using all of the processing power available on the cores, but on the second pass all 12 threads were at
Benchmark Results: It's no surprise that once overclocked the Intel Core i7 3770k is significantly faster than running at default settings. The first pass was more than 40 frames per second faster than running at default speeds, the second pass was nearly 11 frames per second faster or 26.9% faster. Despite running at the same 4.7GHz clock speed the Intel Core i7 3770K 'Ivy Bridge' Processor was able to out perform the second generation Intel Core i7 2600K by ~3.6 frames per second on the processor intensive second pass.
3DMark Vantage is the new industry standard PC gaming performance benchmark from Futuremark, newly designed for Windows Vista and DirectX10. It includes two new graphics tests, two new CPU tests, several new feature tests, and support for the latest hardware. 3DMark Vantage is based on a completely new rendering engine, developed specifically to take full advantage of DirectX10, the new graphics API from Microsoft.
The Performance settings were used for testing, so a resolution of 1280x1024 was used.
Benchmark Results: When running overclocked the Intel Core i7 3770k CPU Score was 25.6% faster than at the default clock speeds. The Intel Core i7 2600K running at 4.7GHz wasn't quite able to keep up with the 3770K Ivy Bridge processor. The CPU score was more than 1500 points south of the Ivy Bridge score.
3DMark 11 is the latest version of the world’s most popular benchmark for measuring the 3D graphics performance of gaming PCs. 3DMark 11 uses a native DirectX 11 engine designed to make extensive use of all the new features in DirectX 11, including tessellation, compute shaders and multi-threading.
Since Futuremark is releasing 3DMark11 today we decided to run the benchmark at both performance and extreme presets to see how our hardware will run.
Benchmark results: Not a surprising result, overclocked the Intel Core i7 3770k had a physics score that is 23.5% faster than at default speeds. The overall score only increased by 58 points though, this is indicative of being GPU limited with our Radeon HD 6950. The Physics score in 3DMark 11 shows the most difference between our processors and their settings. At 4.7GHz the Intel Core i7 3770K 'Ivy Bridge' processor continues to reign supreme edging out the 2600K at 4.7GHz by more than 500 points.
Intel 'Ivy Bridge' Overclocking Temperatures
Curious about the temperatures while overclocking, we fired up Core Temp 1.0 RC3 while running the AIDA64 System Stability test. Idle temperatures were taken after 15 minutes after booting to the desktop. Load temperatures were taken after 15 minutes as well.
The average temperature of the Intel core i7 3770k under a full load with default settings was only 54.5 degrees Celsius. Once we started pumping 1.35 Volts through the processor our temperatures increased dramatically, our average temperature across all of the cores was 92.5 Degrees Celsius, and one of the cores was hitting as high as 96 degrees Celsius! The Intel Core i7 2600K was more than 20 degrees Celsius cooler than the Core i7 3770K 'Ivy Bridge' Processor under the same circumstances even though we were running more voltage through it!
Intel 'Ivy Bridge' Overclocking Power Consumption
Since power consumption is a big deal these days, we ran some simple power consumption tests on our test beds. The systems ran with identical power supplies, Solid-Sate Drives, Memory kits and motherboards from the same company. To measure idle usage, we ran the system at idle for one hour on the desktop with no screen saver and took the measurement. For load measurements, we fired up the AIDA64 system stability test.
The overclocked performance of the Intel Core i7 3770k has clearly been better than at default speeds. Though when overclocked the Intel Core i7 3770k power consumption increases substantially. At idle the default settings draw only 81 Watts at idle, overclocked to 4.7GHz the idle power consumption increases to 118 Watts which is a 45.7% jump. Once we loaded up the Intel Core i7 3770k with the AIDA64 System Stability test the system power consumption jumped from 142 Watts up to 221 Watts! That's an increase of 55.6%. If you're overclocking you will lose efficiency, but gain overall system performance.
Final Thoughts and Conclusion
The Intel 'Ivy Bridge' system is clearly a strong platform. When we looked at the performance with our initial article it was clearly faster than the previous generation was. At the same time, there are clearly some... not sure if I would say flaws, but definitely some concerns for enthusiasts. It seems that the days of hitting 5.0GHz on air cooling are gone, at least for this generation of Intel LGA1155 processors. What isn't clear at this point, is if we are strictly being limited by temperature, or if the new 22nm die just isn't as overclocking friendly as it's predecessor.
Today we weren't able to bring our Intel Core i7 3770K 'Ivy Bridge' processor beyond 4.7GHz with complete stability. This is a little disappointing, but not the end of the world and we are still getting a massive overclock for 'free' so to speak. We also have to keep in mind that processor frequency isn't quite as important as it once was. A short time ago we took a look at performance scaling across several of the Intel 'Sandy Bridge' Processors and our AMD Radeon HD 7950. There truly wasn't as much of a difference as we had expected to see. That isn't saying that there is no difference, but if you're PC's primary concern is gaming, 100-300MHz isn't going to make or break the experience. Especially if you consider that when it comes to clock to clock performance, the Intel Core i7 3770K 'Ivy Bridge' processor is faster than the Intel Core i7 'Sandy Bridge' platform. We saw this in our launch article at default speeds with the Intel Core i7 2700K and again today with our Intel Core i7 2600K clocked at 4.7GHz!
Where the problem seems to reside, is in the temperatures. When our Intel Core i7 3770K was clocked at 4.7GHz, we were pushing the core temperature in to the mid 90's. While the maximum temperature has been increased to 105 degrees Celsius, it is still to hot for my taste.
Looking at the Core Temp 1.0 RC3 screen shot during our temperature testing, we can see that we may have a reason to be worried. Our average temperature when running the AIDA64 System Stability test was 92.5 degrees Celsius, but our hottest core was at 96 degrees Celsius. That's only nine degrees away from the Tj. Max! The real kicker to this is comparing our Intel Core i7 2600K 'Sandy Bridge' Temperatures. Under the same load with the AIDA64 System Stability test we topped out with an average temperature of only 70.75 degrees Celsius and the hottest core was only 75 degrees Celsius! That's more than 20 degrees difference and the 2600K 'Sandy Bridge' Processor is capable of going further yet.
Despite the temperature concerns, there is a bit of shining light for overclockers! Earlier this year Intel introduced their Performance Tuning Protection Plan. If you aren't familiar with the PTPP program from Intel, it's something worth looking into if you run certain 'K', 'X', or any LGA2011-socketed boxed processors. The PTPP plan gives you full warranty protection on your processor no matter how you kill it. If you choose to run an insane amount of vCore while running a stock CPU cooler, Intel will cover it. If you go with a slightly more extreme cooling solution like Liquid Nitrogen (LN2) and destroy your chip, Intel will cover it! It's a great option for those of us that like to push the limits of our hardware! Of course, this isn't free from Intel, but it's a small investment compared to the cost of having to replace a chip. Heck, it's a free replacement plan, so if a new stepping comes out you might be able to switch out your processor with no questions asked.
- Intel Core i5-2500K
- Intel Core i5-2550K
- Intel Core i7-2600K
- Intel Core i7-2700K $25.00
- Intel Core i5-3570K
- Intel Core i7-3770K $25.00
- Intel Core i7-3820
- Intel Core i7-3930K
- Intel Core i7-3960X
The latest platform from Intel isn't without its issues. Temperatures are by far the primary concern that we have seen on this platform though. Pushing into the mid-90's is a little to hot for my comfort level, especially when the second generation 'Sandy Bridge' was so strong with respects to overclocking and temperatures. Clock for clock the third generation Intel 'Ivy Bridge' is faster but it does run significantly hotter. If you aren't looking for the highest possible CPU frequency I would easily recommend an Intel 'Ivy Bridge' processor. The 'Ivy Bridge' processor brings more to the table than just a boost in CPU performance. Depending on your system configuration and what you will be using it for you can see a performance difference with the Intel HD 4000 graphics as well as PCIe x16 Gen 3 expansion slots.
Legit Bottom Line: The Intel Core i7 3770K 'Ivy Bridge' processor may require a bit more cooling than we previously needed on the Intel 'Sandy Bridge' product stack. Though the 3770K is still a great processor that easily pushes past 4.5Ghz and with a little tweaking 4.7GHz-4.8GHz is quite achievable!