Hardware: Core i7 920, Asus X58, Corsair DDR3
It may not be a mainstream system yet, but we decided to use a Core i7 machine for several reasons. First of all, Core i7 is currently the fastest processor available, and we would expect performance enthusiasts to go for it if their budget allows. AMD’s Phenom II would be an almost-equivalent choice, and we've already performed this little experiment on that platform.
The second reason for using Core i7 is its power efficiency. An X58 platform with Core i7 is not a low-power solution at all. In fact, our test system required at least 109 W idle power, which is more than any Core 2 Quad system based on a 45 nm processor and a P45 platform would require. However, Core i7 is far superior to Core 2 when it comes to performance per watt, as the performance benefits usually are larger than the incremental power required.
Our platform of choice is Asus' P6T, which is an enthusiast X58 chipset motherboard. It’s not the company's top-of-the-line model, but it was designed for overclockers and other performance-seeking users nonetheless. We had no problems running Core i7 samples at more than 4.0 GHz using a Core i7 Extreme 965. We used this to ensure that the motherboard would not be bottlenecking higher overclocks on the Core i7 920, which is a much more affordable processor.
We used top tier memory, a very respectable hard drive, and a modern graphics card on our overclocking rig. Our memory was Corsair’s DDR3-1600 Dominator series, the TR3X6G1600C8D, in a 6 GB triple-channel configuration. We did not take full advantage of the possible DDR3-1600 speed, as we started off at the specified DDR3-1066 speed for the regular Core i7 920 (stepping up to the 965 Extreme increases that default to DDR3-1333). System to memory ratio was 2:8 at the 133 MHz base speed, which results in a 533 MHz DDR3-1066 memory speed. We changed the memory multiplier to 2:6 to keep memory speeds within the same levels during our race to 4.0 GHz core clock. Of course, it is possible to fire up the memory voltage and clock speed as well, but this won’t deliver performance gains anywhere near to what a 333 MHz processor clock speed bump can deliver.
Finally, we selected a Zotac GeForce GTX 260² 55 nm graphics card based on the 216-core GPU, which delivers powerful DirectX 10 graphics performance at reasonable power consumption levels. A higher-performance graphics card would deliver better game performance, but it would have decreased the relative power consumption difference in our tests. The Zotac card comes with 896 MB GDDR3 memory, is based on the Nvidia reference design, and comes bundled with Grid.
typo on oc page.
1275v for cpu voltage @ 183mhz
It looks like we could use an i7 version of AMD Overdrive.
There will be times, especially in my line of work, where I need to do some seriously intensive work that a hefty overclock, like the 3.8 or 4GHz, will greatly benefit me, however my everyday operation wouldn't need to go much past stock speeds.
Storing OC profiles in a real-time utility would be fantastic: fire up the stupid 4GHz mode when I need to render my 20 minute HD graphic sequence, switch to 3.33GHz for some gaming, and drop to 2.6 stock to check my e-mail.
Yes, the 4GHz mode sucks stupid levels of power, but if you have the freedom to run it in short spells then it's easier to live with.
I thought though this test was sticking with the stock Intel cooler - what's that hefty copper thing then on page 5?
Thank you for this article, I'm going build an I7 920 / Asus P6T setup at the end of may when the i5 / P55 components come out, I'm waiting mainly for price reasons. I currently run an AMD 3200+ Barton / Asus A7N8X setup which seriously needs to be replaced.
This article is exactly what I want, I've a novice overclocker and any guidance is welcomed. I'm running a Koolance water cooling solution and it'll be used for my new i7 920 setup, I'll definitely be overclocking it to 3.33Ghz to begin with, and the maybe 3.6Ghz at a later date to prolong it's life with regards to performance.
What is the PSU used? Does it have a factor on the testing?
does anyone really need to overclock such a fast quad core chip
@pete3867:
If you want to spend £850 on the 3.2GHz model then go right ahead. The rest of us will save £600 and overclock our 2.66GHz model and match performance.
The question has never about if you "need" to overclock. Strictly speaking you don't need to overclock because there's a faster model than you can just buy.
But we're always looking to get the most for our money in every walk of life, and certainly with CPUs over the past few years if you can match performance of a more expensive model by overclocking a cheaper one, then frankly you'd be insane not to do it.
Besides, "fast" is a relative term. Right now, the i7 does wet on everything around it so *right now* you may not "need" to do anything with it. However, who knows what's around the corner to beat these things - in a few years you may "need" to overclock your investment to keep pace with what's around.
yeah , I guess your right , I just feel that in general terms modern cpu 's are (at the moment at least )way ahead of the software demands placed on them .
@pete3867:
Again, it depends on what you're doing. If an Atom-based netbook can do office and web stuff perfectly well then why do you need a Core i7? Gaming has always been more about the GPU for a quite while now so until recently you could get away with an older CPU.
Media creation, on the other hand, can never have too much processing power. At work I upgraded my ageing P4 3.2GHz to a (then) shiny Core 2 Duo 2.4GHz and was blown away by how much power I had and how much faster I could do all my stuff. Very quickly though I used up that potential knowing I could do more with it than before, so now I'm back to long render times.
We had some 8GB Quad Core systems in and the same applied there - marvelled at the power increase, only to be negated by me doing more with it. The same will apply to by stupid i7 rig I build in a few months.
Basically, in media creation you can never have too much power, and as I stated in my first post, having an Overdrive-style utility where I can quickly enable "stupid 4GHz overclock mode" for my renders would be so good - we need every ounce of juice we can muster.
Your results are biased towards the setups not operating at stock voltage. If you increase voltage when overclocking, you should also undervolt where possible rather than use stock voltage.
It looks like we could use an i7 version of AMD Overdrive.There will be times, especially in my line of work, where I need to do some seriously intensive work that a hefty overclock, like the 3.8 or 4GHz, will greatly benefit me, however my everyday operation wouldn't need to go much past stock speeds.Storing OC profiles in a real-time utility would be fantastic: fire up the stupid 4GHz mode when I need to render my 20 minute HD graphic sequence, switch to 3.33GHz for some gaming, and drop to 2.6 stock to check my e-mail.Yes, the 4GHz mode sucks stupid levels of power, but if you have the freedom to run it in short spells then it's easier to live with.
I completely agree, nowadays an OC profile system would be much more versatile. Compared to older systems, which may demand a constantly OC'ed CPU, newer systems at stock should rival older OC'ed systems. Profile's for power management would be an excellent idea.
Hey, LePhuronn check out http://www.overclockingwiki.org/in [...] =Clockgen.
Fixed link: http://www.overclockingwiki.org/in [...] e=Clockgen
You can run 3.33GHz with Turbo mode on much lower than stock voltages. I'm currently running it on 1.15V and it could probably be lower than that. This would obviously make 3.33GHz an ever more appealing choice when looking at power consumption.
What a hike in power consumption to get that thing stable at 4GHz..
An OC compromise that works very well for me as a permanent setting and which doesn't cause me i920 core temps above 55degC whether under gaming or under Prime is: CPU and QPI parity at 3240MHz by means of 180MHz base clock, x18 CPU multiplier, 20x Uncore multiplier (i.e. Uncore clock 3600MHz) & 10x Memory Multiplier (i.e my 6GB of OCZ memory at 1800MHz, set 8-8-8-26). Air cooler is a Thermalright u120e & mobo is an EX58-UD5. All voltages are stock. 30days of excellent glitch-free performance so far. I have no ambition to go for bigger numbers & like to keep things simple.