I own the DZ77GA-70k paired with an i5-3570K. Since the Ivy Bridges run a lot hotter than Sandy Bridges - my i5-3570K gets around 70°C (prime95) at Stock clocks + voltages (please note, that I got a Thermalright Archon) - I tried to undervolt the CPU. The VID is set to 1.2V, I managed to undervolt to 1.0V, which is the minimum. My processor now runs around 55°C and is rock stable. So, I wanted to undervolt the CPU a little bit further, but I already reached the selectable minimum. When Vcore is set to 1.0V, CPU-Z shows me 1.016V for it. When Vcore is set to "Default", CPU-Z shows me 0.976V. So, it seems that the DZ77GA-70k can handle smaller Vcores, but I just can't select them in BIOS. The engineers might have thought, that most people want to overclock and raise the voltages. But Ivy Bridge is just running too hot, so I have to undervolt it. I don't think, that it is something too complicated for the BIOS programmers to do and I would love to see lower voltages in future BIOS updates.
You should also keep in mind, that the i5-3570K is one of the most demanding Ivy Bridge CPUs. There are dual dore i3 Ivy Bridges, which may even run at lower clocks and voltages. MSI and the other big Mobo manufacturers are also supporting undervolting lower than 1.0V (see http://www.anandtech.com/show/5763/undervolting-and-overclocking-on-ivy-bridge AnandTech - Undervolting and Overclocking on Ivy Bridge); AnandTech managed to undervolt Ivys to 0.9V - stable!
Aside from this, I would love to see Undervolting support across all 7 Series Mainboard, but at least also on the DH77DF. I think, that it is absolutely essential for an ITX board to have undervolting support. Intel mobos are godly power savers, so having a bonus of undervolting would make it a legendary show stealer.
I hope, that someone from Intel will read this and forward it to their BIOS programmers.
Thank You for your time,
No one answered, so I decided to share my results with undervolting here to get the ball rolling.
Intel Core i5-3570K
Intel DZ77GA-70k Mobo
16GB Corsair DDR3-1600 CL9 (4 Module)
128GB Samsung 830 SSD
2 x 640GB Western Digital Caviar Black
Thermalright Archon CPU cooler
I've used CPU-Z to read the voltages, an external device for power consumption, RealTemp for CPU temperature and prime95 to produce 100% load.
VCore Idle / Load / Power Consumption Idle / Load / Temps at Load
0.976V / 1.224V / 72W / 155W / 67°C - 70°C (with Vcore set to "Default")
1.016V / 1.032V / 73W / 130W / 55°C - 58°C (with Vcore set to the lowest selectable value of "1.000V").
Please note that by just decreasing voltages, I could save 25W power on load and my CPU ran about 12°C cooler. And that's not even the limit. AnandTech reached 0.9V with ease (with an i7-3770K on load ) and cut the temperature and power consumption even more. Under idle, there is even more room. So, we really need lower values for the voltages; the board is able to set lower voltages, but they just aren't shown in the menu (the CPU voltage starts at "Default", then goes on with "1.000V" and increases by "+0.005V" up until around "1.9V").
Don't hesitate to share your thoughts and results. With the coming i3 Ivy Bridges, this is an ABSOLUTELY essential feature! Especially for the ITX board DH77DF, where room for an aftermarket cooler is limited and where power consumption and noise production is very important.
I would appreciate a CPU undervolting feature on the DH77DF, too. Especially for an ITX form-factor mainboard which is often used in mediacenters this is an importent feature and competitors like MSI and ASUS are offering it in their ITX product line. Hopefully this is the right place for a feature request - I am not sure if Intel staff is reading this.
If Intel could under volt reliably then they would, as they all about more processing for less watts. Also we shouldn't overlook the fact that under volting happens already, automatically, to save power, that is what SpeedStep/Turbo Boost is all about. When the CPU has little work to do it clocks back to a low speed and the voltage drops considerably. When it needs to do work, the only reliable way to do this at a faster clock speed is to increase the voltage back up to normal levels.
All CPUs are tested individually and given a voltage profile based on reliability, yes you might be able to drop the voltage some more in your own home, but then you are unable to do the kinds of test Intel will do when they create the original voltage profile. You can't be sure the CPU is going to work error free at your lower voltage in all cases.
Also there are challenges from moving from very low volts to higher voltages for the voltage regulator, sometimes it just isn't practical for the voltage regulator to support extremely low volts as the sudden ramping up to normal voltages is too much strain causing very quick changes in current requirements. So I suspect there is a practical range the VR has to only support.
When a CPU is tested and comes of the production line with the ability to run at a very low voltage, it is sold as such.
If you really need the absolute lowest power requirements, it is a case of buying components designed for that, rather than trying to make components work in a way they are not designed to do.
thank you Phil for your answer. You are right that undervolting may result in a reduced reliability, but there are many people out there who would accept this reduced reliability to get a lower power consumption and less heat without buying an expensive low voltage CPU. For typical home theater PC usage the reliability is not critical and undervolting in fact works fine on many mainboards from competitors. I would greatly appreciate such a feature, and I think as it is only an option in BIOS, nobody is forced to use it if he needs maximum reliability. There are a lot of people in the HTPC community who won´t buy a DH77DF because it doesn´t support undervolting (although it is a great mainboard)...
thank your for your answer ;)! As you said: undervolting already happens today. However, it isn't enough. Intel has to set a much higher VID value than really needed, to guarantee, that their CPUs run on EVERY computer / mainboard / setup on this planet. And that VID value is just too high for a high quality setup.
"Why does Intel set a VID?" This is due to the manufacturing process, where transistors can't be produced in the exactly same quality. Some of them work at higher voltages, some of them could work at lower volts. So, you have to set the higher value, to have all transistors working. When a transistor fails, you might get an error message, a BSOD or your PC won't simply boot.
As for my part, I'm using very high quality parts, like the Intel Mainboard and a premium Corsair power supply. And my CPU runs about ~0.2V lower than what Intel set my CPU to. I'm running this setup at the lowest possible Vcore for about 1 month and I didn't experience ANY issues. Also, this setup is absolutely prime95 stable - so, I don't see any contraindications, why my (tested) undervolted setup should not work reliable. In fact, it's saving me 25W on load and giving me a more silent and cooler system, for absolutely no drawbacks.
Of course, I can't use exactly the same tools as Intel to check reliability, but we have our own tools, to check if a CPU works reliable, or not (like prime95). And that worked well for over a decade for thousands of users, so nothing wrong here I guess.
As for the voltage regulators: I don't know the exact specifications for them. But my tests showed, that they can work with lower voltages than the lowest selectable value on the DZ77GA-70k. Also, ASRock's H77M-ITX 70€ ITX mainboards are able to undervolt way down to at least 0.5V. First, that's an ITX, second it's a low-end mainboard and third it's just 70€. My Intel mainboard did cost 220€ and should use a lower-end voltage regulator than that ASRock ITX mainboard? I can't imagine that, sorry.
Also, I don't think, that there's a huge difference between 1.0V -> 1.2V and 0.8V -> 1.0V. It's a +0.2V, the voltage regulator should handle it.
The DZ77GA-70k is an Intel extreme mainboard, made for overclockers and enthusiasts and is sold as such. Intel even put an automatic overclocking assistant in it. It is designed to support voltages and clocks not within specifications (why else should Vcore go up to 1.9V? That would immediately kill any Ivy Bridge CPU). So, it's designed for that ~0.01% of overclockers, who have access to LN2 for cooling.
Undervolting is also extreme, just in the other direction. Limited support is included in the DZ77GA-70k, but I wan't more (just like 1.9V is plain overkill (or not? Look at http://valid.canardpc.com/show_oc.php?id=2386564 CPU-Z Validator 3.1), give us 0.5V for the lowest value). The limiting factor right at the moment is the mainboard, not the CPU, and that's kinda sad.If you really need the absolute lowest power requirements, it is a case of buying components designed for that, rather than trying to make components work in a way they are not designed to do.
I guess you're talking about ATOM or the AMD E-Series? Well, with a Sandy Bridge CPU and undervolting / underclocking, you can reach lower power consumption + higher performance. You just need a mainboard with undervolting capability. Funnily, the DH67CF supports undervolting, the DH77DF does not.
I guess you're talking about ATOM or the AMD E-Series? Well, with a Sandy Bridge CPU and undervolting / underclocking, you can reach lower power consumption + higher performance. You just need a mainboard with undervolting capability.
That is true, with a DH61DL and a G620 it is possible to reach only 12/14 watts in idle and about 17/18 watts playing a HD movie (http://www.silentpcreview.com/forums/viewtopic.php?f=28&t=63577 http://www.silentpcreview.com/forums/viewtopic.php?f=28&t=63577). And this with a board that cannot undervolt and only recently started to support lower voltage rams. Only for a comparison, i once had a E-350 motherboard and it used to idle at 14 watts (with a picopsu power supply and a ssd).
Phil_l, first of all thank you for your answer. I mean no disrespect, but according to the above topic the lower voltage CPU (G620T) had a higher power consumption in idle mode and while playing a HD movie. I may be wrong, but I think the main difference of the T and S series of CPUs is the limit the full power consumption. Again, i mean no disrespect.
Since the DH77DF is a mini-itx HTPC board it will rarely use a lot of power and the undervolt will result in lower temperatures and lesser noise.
Funnily, the DH67CF supports undervolting, the DH77DF does not.
That is a good thing. Let's hope Intel staff is reading this and release a bios with this feature.
Message edited by: erc&# 13; Just to correct the link
I would like to see the undervolting feature as well for all the reasons that have been mentioned here already. Besides this, why can't the DH77DF use the beautiful BIOS interface like Intel Extreme boards have? If it makes the Mini ITX board more expensive - alright, so be it. But as of know we Mini-Itx fans do not have the option unless a BIOS update is being offered to us.
If you're talking about the visual bios, you should check out the newer bios updates. It looks very nice.
Though, it would look much much nicer if there was an undervolting feature.
I have ordered the Intel DH77DF together with the i5 3570K just today.
Still have the DH67CF with the i5 2500K in use which I'm actually very happy with.
I'm curious about the future of Mini iTX with Haswell, the successor of Ivy Bridge.
There are going to be new mainboards with 1150 sockets. Exciting times ahead.