Underclock 4770k for small server use.

Phixsator · 30 Nov 2017 at 08:46

Let me set the background first. Im on the z87 platform powered by a 4770k for my main rig, i also got a z97 mobo and everything else except the CPU for that motherboard. Now i managed to get my hands on a 4790k and 16gigs of 1866mhz ram for around 110 pounds, dirt cheap if you ask me, and i did this due to the price as it allows me to upgrade my server with some proper hardware. Now ill be swapping the 4790k into my main rig instead of the 4770k and hopefully i can have my 4,4ghz without hitting 90c on AIO water, just a small bonus on the side.

Now my current server is doing better than i would expect from a pathetic AMD Athlon 5150 and it takes no power what so ever, we are talking less that 25 watts, but it is still weak and game servers on it is not a good experience when playing more than 2

. Now the 4770k is of course a huge upgrade but i don't need it to run full speed 3,9ghz as i'm not interested in 150+ watt of power draw. To the main topic then. Im of course going to underclock the 4770k, seems backwards no?

. I was thinking 2,0ghz for starters if i can even get it to go that low. Was wondering if anyone have experimented with a similar idea and what your results were? what volts was needed? did you measure power draw?

I know as you scale up an overclock power has to been increased exponentially. I was sort of hoping for the same thing but in backwards order for an underclock. That once i hit 2,5-2,0ghz that the power required is so low that its is next to none, at least compared to full tilt 3,9ghz. I would be very happy if i got get it to hit around the 60-75 watt mark. Am i being unrealistic?

TL;DR: Have you underclocked a 4770k(or similar) before and what where your power draw results from it? Was it for server use?

Danny75 · 30 Nov 2017 at 09:13

Phixsator said:
I was thinking 2,0ghz for starters if i can even get it to go that low.

This is a Cinebench run with Windows Power Option Maximum processor state to lowest possible (800Mhz). Didn't fancy going into BIOS and changing anything right now.

https://imgur.com/ZvIOP88

And this is with 4300MHz:

https://imgur.com/Bm9nynz

Memory seems more of a power problem than CPU when in such low states.

facboy · 30 Nov 2017 at 09:29

Well the TDP of 4770k is 84w anyway, so not sure where the other 65w would come from. And obviously it doesn't use that all the time anyway, it depends on the load, even when it is running at maximum boost.

Eg my 8700k uses 73w in realbench with all cores at 4.3 and fully loaded (stock). With a mild o/c to 4.7 on all cores this rises to 105w. But in eg Destiny 2, with all cores at 4.7 it only uses 23w because the machine is not fully loaded. I have all the power management options enabled in the bios so it's probably down-clocking quite aggressively.

Phixsator · 30 Nov 2017 at 09:32

Uhhh, that looks very promising. Didn't think about using windows power options to control it so thanks for that. A hell of a lot easier to control on the fly incase there is this one application that needs a bit of a boost.

If those reading are correct then its going to be extremely efficient at lower clock speeds. I might even be able to cool with with a heatsink without a fan if i keep the clocks low enough.

facboy said:
Well the TDP of 4770k is 84w anyway, so not sure where the other 65w would come from. And obviously it doesn't use that all the time anyway, it depends on the load, even when it is running at maximum boost.

Eg my 8700k uses 73w in realbench with all cores at 4.3 and fully loaded (stock). With a mild o/c to 4.7 on all cores this rises to 105w. But in eg Destiny 2, with all cores at 4.7 it only uses 23w because the machine is not fully loaded. I have all the power management options enabled in the bios so it's probably down-clocking quite aggressively.

There is no way on earth your 8700k only drains 73watts at the wall full tilt, no way. If you are looking at coretemp's readings or something similar you are doing it wrong. A reader on the powerplug will tell you different very fast.

Danny75 · 30 Nov 2017 at 09:42

Phixsator said:
Uhhh, that looks very promising. Didn't think about using windows power options to control it so thanks for that. A hell of a lot easier to control on the fly incase there is this one application that needs a bit of a boost.

Agreed. Very handy for laptops when unplugged too, if only browsing etc.

Phixsator · 30 Nov 2017 at 09:45

Danny75 said:
Agreed. Very handy for laptops when unplugged too, if only browsing etc.

Its a 4770k? what volts are you using for that 4,3ghz?

Danny75 · 30 Nov 2017 at 09:48

Phixsator said:
Its a 4770k? what volts are you using for that 4,3ghz?

Yes. 1.296v. It's not a great chip. Need around 1.345v for 4.4 stable, and 1.395 to pass a few benchmarks at 4.5 but isn't totally stable.

facboy · 30 Nov 2017 at 09:50

Phixsator said:
Uhhh, that looks very promising. Didn't think about using windows power options to control it so thanks for that. A hell of a lot easier to control on the fly incase there is this one application that needs a bit of a boost.

If those reading are correct then its going to be extremely efficient at lower clock speeds. I might even be able to cool with with a heatsink without a fan if i keep the clocks low enough.

There is no way on earth your 8700k only drains 73watts at the wall full tilt, no way. If you are looking at coretemp's readings or something similar you are doing it wrong. A reader on the powerplug will tell you different very fast.

sorry, like the previous post it is what HwInfo claims the CPU alone is using. But you are asking about underclocking the CPU, isn't the CPU power draw the relevant thing? I still struggle to see where you're going to use the other 60w even if the CPU was using 84W at full tilt, which it won't be.

Danny75 · 30 Nov 2017 at 09:56

facboy said:
sorry, like the previous post it is what HwInfo claims the CPU alone is using. But you are asking about underclocking the CPU, isn't the CPU power draw the relevant thing? I still struggle to see where you're going to use the other 60w even if the CPU was using 84W at full tilt, which it won't be.

When you add the IA Cores draw, it gives a more accurate idea, even though still software and not 100% trustworthy. Around 167W cpu package + ia cores combined does seem pretty realistic though.

DragonQ · 30 Nov 2017 at 10:14

That's the thing with these modern CPUs being designed primarily for mobile parts: they are insanely efficient at lower speeds. It's only when they have to massively boost the clocks for the higher end desktop parts that their power usage goes through the roof. The same happens with Ryzen at over ~3.5 GHz IIRC.

Phixsator · 30 Nov 2017 at 10:27

Danny75 said:
Yes. 1.296v. It's not a great chip. Need around 1.345v for 4.4 stable, and 1.395 to pass a few benchmarks at 4.5 but isn't totally stable.

your 4770k seems to be a better sample than mine when running both full tilt and underclocked power draw wise. HWINFO is reporting an idle watt draw for package alone of around 17watts @800 core clock with a peak of around 27 watts full tilt in cinebench. This is with factory defaults in bios loaded and then every c state enabled. My ram however is apparently only draining less than 5 watts @ 1866mhz 9-10-9-27. Only difference is likely our boards and i can see you are using HWINFO 5.60 where im on 5.59. So gonna update and see if readings are different.

Danny75 · 30 Nov 2017 at 10:32

Phixsator said:
your 4770k seems to be a better sample than mine when running both full tilt and underclocked power draw wise. HWINFO is reporting an idle watt draw for package alone of around 17watts @800 core clock with a peak of around 27 watts full tilt in cinebench. This is with factory defaults in bios loaded and then every c state enabled. My ram however is apparently only draining less than 5 watts @ 1866mhz 9-10-9-27. Only difference is likely our boards and i can see you are using HWINFO 5.60 where im on 5.59. So gonna update and see if readings are different.

MSI Z87 MPower Max. Four sticks mem @ 2133MHz 9-11-10-27 1.65v. Balanced power plan. Adaptive voltages in BIOS. C states enabled (the default ones).

Phixsator · 30 Nov 2017 at 10:37

Danny75 said:
MSI Z87 MPower Max. Four sticks mem @ 2133MHz 9-11-10-27 1.65v. Balanced power plan. Adaptive voltages in BIOS. C states enabled (the default ones).

Again, thanks for sharing, ill have a look in the bios of my sabertooth z87. Wouldnt surprise me if Asus is boosting something behind the curtains. Wouldn't be the first time.

Danny75 · 30 Nov 2017 at 10:42

Phixsator said:
Again, thanks for sharing, ill have a look in the bios of my sabertooth z87. Wouldnt surprise me if Asus is boosting something behind the curtains. Wouldn't be the first time.

Very welcome.

Could well be. Check LLC. As for memory, you have two sticks, right?

Oh, and my Cache voltage is Adaptive too (and frequency fluctuates from 0.8 to 4.2), that might also be a difference. I've messed with it a lot, Fixed/Adaptive, seems to make no difference in this instance, but could be pulling more power if Fixed.

facboy · 30 Nov 2017 at 11:18

Danny75 said:
When you add the IA Cores draw, it gives a more accurate idea, even though still software and not 100% trustworthy. Around 167W cpu package + ia cores combined does seem pretty realistic though.

The IA Cores Power is a sub-part of the CPU Package Power, you're not meant to add them together: https://www.hwinfo.com/forum/Thread-CPU-power-IA-vs-package-and-package-power-can-t-show-graph

Phixsator · 30 Nov 2017 at 11:27

facboy said:
The IA Cores Power is a sub-part of the CPU Package Power, you're not meant to add them together: https://www.hwinfo.com/forum/Thread-CPU-power-IA-vs-package-and-package-power-can-t-show-graph

good to know.. ty. In the end i'll measure from the power plug but for now a rough estimate through software is fine.

facboy · 30 Nov 2017 at 11:30

post your results, i'd be curious to know anyway! i think these are very power-efficient when idle or only low load.

Phixsator · 30 Nov 2017 at 11:37

facboy said:
post your results, i'd be curious to know anyway! i think these are very power-efficient when idle or only low load.

I shall as soon as the 4790k arrives in the mail and i can rebuild both the main rig and the server as the server right now is using a micro atx board in a tiny tiny case powered by a laptop brick

and that is going to a full fledge atx in a midi tower.

sidenote: any know of a good thin client/server solution for use with windows and an android tablet? My better half is complaining a little about the performance on certain 3d tasks on her tablet and i'd have more than enough power to spare once i'm done with the server setup.

Danny75 · 30 Nov 2017 at 12:31

facboy said:
The IA Cores Power is a sub-part of the CPU Package Power, you're not meant to add them together: https://www.hwinfo.com/forum/Thread-CPU-power-IA-vs-package-and-package-power-can-t-show-graph

Ah, thanks for enlightening me. Had always thought HWiNFO64 separated Package from IA Cores.

AiiR · 30 Nov 2017 at 13:32

I manage my HTPC power draw through the windows power plan rather than downclocking through the bios. It's an i5 4670k at 4ghz but downclocks to 800mhz on idle which sips on power as it's on 24/7. The 4ghz only kicks in during games.