The Sandy Bridge Review: Intel Core i7-2600K, i5-2500K and Core i3-2100 Tested
by Anand Lal Shimpi on January 3, 2011 12:01 AM ESTPower Consumption
Power consumption is very low thanks to core power gating and Intel's 32nm process. Also, when the integrated GPU is not in use it is completely power gated as to not waste any power either. The end result is lower power consumption than virtually any other platform out there under load.
I also measured power at the ATX12V connector to give you an idea of what actual CPU power consumption is like (excluding the motherboard, PSU loss, etc...):
| Processor | Idle | Load (Cinebench R11.5) |
| Intel Core i7 2600K @ 4.4GHz | 5W | 111W |
| Intel Core i7 2600K (3.4GHz) | 5W | 86W |
| AMD Phenom II X4 975 BE (3.6GHz) | 14W | 96W |
| AMD Phenom II X6 1100T (3.3GHz) | 20W | 109W |
| Intel Core i5 661 (3.33GHz) | 4W | 33W |
| Intel Core i7 880 (3.06GHz) | 3W | 106W |
Idle power is a strength of Intel's as the cores are fully power gated when idle resulting in these great single digit power levels. Under load, there's actually not too much difference between an i7 2600K and a 3.6GHz Phenom II (only 10W). There's obviously a big difference in performance however (7.45 vs. 4.23 for the Phenom II in Cinebench R11.5), thus giving Intel better performance per watt. The fact that AMD is able to add two more cores at only a 13W load and 300MHz frequency penalty is pretty impressive as well.
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-=Hulk=- - Monday, January 3, 2011 - link
That's crazy, are the chipsets PCI-e line still limited to v1 (250MB/s) speed or what????http://images.anandtech.com/reviews/cpu/intel/sand...
mino - Monday, January 3, 2011 - link
No, you read it wrong.There are altogether 8 PCIE 2.0 linex and all can be used independently, aka s as "PCIe x1".
The CPU-Chipset bandwith however is a basic PCIe x4 link, so do not expect wonders is more divices are in heavy use ...
-=Hulk=- - Monday, January 3, 2011 - link
No!Look at the PCI-e x16 from the CPU. Intel indicates a bandwidth of 16GB/s per line. That means 1GB/s per line.
But PCI-e v2 has a bandwidth of 500MB/s per line only. Thats mean that the values that Intel Indicates for the PCI-e lines are the sum of the upload AND download bandwidth of the PCI-e.
Thats means that the PCI-e lines of the chipset run at 250MB/s speed! That is the bandwidth of the PCI-e v1, and Intel has done the same bullshit with the P55/H57, he indicates that they are PCI-e v2 but they limits their speed to the values of the PCI-e v1:
P55 chipset (look at the 2.5GT/s !!!) :
"PCI Express* 2.0 interface:
Offers up to 2.5GT/s for fast access to peripheral devices and networking with up to 8 PCI Express* 2.0 x1 ports, configurable as x2 and x4 depending on motherboard designs.
http://www.intel.com/products/desktop/chipsets/p55... "
P55, also 500MB/s per line as for the P67
http://benchmarkreviews.com/images/reviews/motherb...
Even for the ancient ICH7 Intel indicates 500MB/s per line, but at that time PCI-e v didn't even exist... That's because it's le sum of the upload and download speed of the PCI-e v1.
http://img.tomshardware.com/us/2007/01/03/the_sout...
DanNeely - Monday, January 3, 2011 - link
Because 2.0 speed for the southbridge lanes has been reported repeatedly (along with a 2x speed DMI bus to connect them), my guess is an error when making the slides with bidirectional BW listed on the CPU and unidirectional BW on the southbridge.jmunjr - Monday, January 3, 2011 - link
Intel's sell out to big media and putting DRM in Sandy Bridge means I won't be getting one of these puppies. I don't care how fast it is...Exodite - Monday, January 3, 2011 - link
Uh, what exactly are you referencing?If it's TXT it's worth noting that the interesting chips, the 2500K and 2600K, doesn't even support it.
chirpy chirpy - Tuesday, January 11, 2011 - link
I think the OP is referring to Intel Insider, the not-so-secret DRM built into the sandy bridge chips. I can't believe people are overlooking the fact that Intel is attempting to introduce DRM at the CPU level and all everyone has to say is "wow, I can't WAIT to get one of dem shiny new uber fast Sandy Bridges!"I for one applaud and welcome our benevolent DRM overlords.....
http://www.pcmag.com/article2/0,2817,2375215,00.as...
nuudles - Monday, January 3, 2011 - link
I have a q9400, if I compare it to the 2500K in bench and average (straight average) all scores the 2500K is 50% faster. The 2500K has a 24% faster base clock, so all the architecture improvements plus faster RAM, more cache and turbo mode gained only ~20% or so on average, which is decent but not awesome taking into account the c2q is 3+ year old design (or is it 4 years?). I know that the idle power is significantly lower due to power gating so due to hurry up and wait it consumes less power (cant remember c2q 45nm load power, but it was not much higher than this core 2011 chips).So 50%+ faster sounds good (both chips occupy the same price bracket), but after equating clock speeds (yes it would increase load and idle power on the c2q) the improvement is not massive but still noticeable.
I will be holding out for Bulldozer (possibly slightly slower, especially in lightly threaded workloads?) or Ivy Bridge as mine is still fast enough to do what I want, rather spend the money on adding a SSD or better graphics card.
7Enigma - Monday, January 3, 2011 - link
I think the issue with the latest launch is the complete and utter lack of competition for what you are asking. Anand's showed that the OC'ing headroom for these chips are fantastic.....and due to the thermals even possible (though not recommended by me personally) on the stock low-profile heatsink.That tells you that they could have significantly increased the performance of this entire line of chips but why should they when there is no competition in sight for the near future (let's ALL hope AMD really produces a winner in the next release) or we're going to be dealing with a plodding approach with INTEL for a while. In a couple months when the gap shrinks (again hopefully by a lot) they simply release a "new" batch with slightly higher turbo frequencies (no need to up the base clocks as this would only hurt power consumption with little/no upside), and bam they get essentially a "free" release.
It stinks as a consumer, but honestly probably hurts us enthusiasts the least since most of us are going to OC these anyways if purchasing the unlocked chips.
I'm still on a C2D @ 3.85GHz but I'm mainly a gamer. In a year or so I'll probably jump on the respin of SDB with even better thermals/OC potential.
DanNeely - Monday, January 3, 2011 - link
CPUs need to be stable in Joe Sixpack's unairconditioned trailer in Alabama during August after the heatsink is crusted in cigarette tar and dust, in one of the horrible computer desks that stuff the tower into a cupboard with just enough open space in the back for wires to get out; not just in an 70F room where all the dust is blown out regularly and the computer has good airflow. Unless something other than temperature is the limiting factor on OC headroom that means that large amounts of OCing can be done easily by those of us who take care of their systems.Since Joe also wants to get 8 or 10 years out of his computer before replacing it the voltages need to be kept low enough that electromigration doesn't kill the chip after 3 or 4. Again that's something that most of us don't need to worry about much.