What hardware is ideal for underclocking?

[Okjoek]

I was watching an older video with Linus on undervolting and he brings up underclocking as well.

These sort of things are kind of interesting to me. I'm not sure what hardware to get for it though. Linus claims that I'd be better off just getting a lower power CPU in the first place if I wanted lower power. By that logic I should want something like an i7 6700T which is insanely powerful for its 35W TDP, but like my current CPU it's locked so I can't over/underclock, although I've never really cared for overclocking anyways.

 

Maybe I should wait for AMD's Zen because most of their CPUs are usually unlocked anyways aren't they?

[paddy-stone]

I can't think of a reason why anyone would want to underclock... the CPUs generally only clock as high as you need at the time. My i7 6700k only draws approx 6-8W while idling and just have a few webpages open etc, yet has the power when I need it also.

[vtecf20c]

your mobo is a Z77, you should be able to change volts of your cpu.

 

you don't need a K cpu for change volts, the K thing is for overclocking.

 

 

[vtecf20c]

8 minutes ago, paddy-stone said:

I can't think of a reason why anyone would want to underclock... the CPUs generally only clock as high as you need at the time. My i7 6700k only draws approx 6-8W while idling and just have a few webpages open etc, yet has the power when I need it also.

power saving and better cooling i think.. 

 

 however i quote you, it's a useless thing, but his i5 is not as good on power saving as your I7, it has an older architecture.

 

anyway he can't underclock it, but usually cpus are very overvolted with standar volts, because any cpu is different, and more volts helps the stability, he can try to undervolt it, it's always better to try undervolt a cpu.

 

[z97]

I don't get the whole fact of trying to under volt it..... Why cause potential instabilities for like 5 or 10 watts of power..

[Clanscorpia]

1 minute ago, z97 said:

I don't get the whole fact of trying to under volt it..... Why cause potential instabilities for like 5 or 10 watts of power..

Its also a lot less heat

[z97]

1 minute ago, Clanscorpia said:

Its also a lot less heat

A lot less? Not really. .005 volts is prolly .5-1c difference

[paddy-stone]

Yes, I can see the point of lowering the volts, so you still have enough volts that you don't get a BSOD but can still use the CPU as normal... that is pretty standard anyway for most overclockers. But underclocking is pointless, if your CPU is only drawing say even 20 Watts while you use it, is still damn good.

You'd save a lot more watts just by making the PC sleep during no usage.

[Clanscorpia]

Just now, z97 said:

A lot less? Not really. .005 volts is prolly .5-1c difference

With my 480 Ive undervolted like 20-30mhz aka 0.03v makes a big difference

 

[vtecf20c]

1 minute ago, z97 said:

A lot less? Not really. .005 volts is prolly .5-1c difference

depends of chip, he can undervolt much more than 0.005

 

for example, my e5450 at stock speed works stable at 1.03v, and default was 1.25v, that is 0.22v , not 0.005.

[z97]

1 minute ago, Clanscorpia said:

With my 480 Ive undervolted like 20-30mhz aka 0.03v makes a big difference

 

You undervolted by dropping the core clocks wat? Unless you want a completely whisper quiet computer it's literally pointless to take away your stability. If heat is an issue buy a better heatsink. If power draw is an issue turn the thing off at night or unplug some of your other things.

[Clanscorpia]

Just now, z97 said:

You undervolted by dropping the core clocks wat? Unless you want a completely whisper quiet computer it's literally pointless to take away your stability. If heat is an issue buy a better heatsink. If power draw is an issue turn the thing off at night or unplug some of your other things.

mV sorry Im dumb. And its doesnt take away from my stability I have a beauty chip  

[vtecf20c]

but i think E5450 is/was (2007..) something special, it uses only 60w on full load at 3.9ghz 

 

 

[Okjoek]

Okay. Thanks for the input. My CPU isn't that bad on power, heat or performance so I don't think it's going to be a huge factor for when I decide to upgrade. What I WOULD like is for my next CPU to use the same or slightly less power while still getting more performance.

 

What do you guys think of an i5 6500?

 

It uses less power and is even better than my i5 3450. On paper atleast.

[SpaceGhostC2C]

59 minutes ago, paddy-stone said:

I can't think of a reason why anyone would want to underclock...

Then you lack imagination  Sometimes you just don't need the speed and don't want power to go up under any circumstances. An example: I currently have an OCed FX 8370E. I may at some point re-purpose it as a server or something. Going bat to stocks would decrease power draw considerably, but I could still go lower, for example to AM3+ Opteron levels, through underclocking, and it would be perfectly fine for NAS or home server. Yes, I could buy new hardware intended for those function, but undervolting will cost me zero, other than a couple weekend afternoons of undervolting fun (si it's win-win )

59 minutes ago, vtecf20c said:

your mobo is a Z77, you should be able to change volts of your cpu.

 

you don't need a K cpu for change volts, the K thing is for overclocking.

 

 

K is for changing multipliers - whether upwards (over-) or downwards (under-) is up to you. You are right in that undervolting is still possible, but once you hit the lowest stable voltage you cannot go further by lowering the multiplier. An unlocked CPU would allow for more aggressive undervolting by simultaneously underclocking.

44 minutes ago, z97 said:

You undervolted by dropping the core clocks wat? Unless you want a completely whisper quiet computer it's literally pointless to take away your stability. If heat is an issue buy a better heatsink. If power draw is an issue turn the thing off at night or unplug some of your other things.

Why would you take away stability? By definition, a successful undervolt is 100% stable, just like a successful overclock. Undervolting is exactly the same as overclocking: finding a stable combination of voltage and clocks. If undervolting was pointless, so would be anything other than overkill voltage for overclocking. Is that really how we overclock?

Moreover, CPU manufacturers will set overkill voltages to make sure every chip works out of the box. So, just like you can try your luck at the silicon lottery and see how far your chip overclocks, you can also play the same silicon lottery and check how low a voltage you can use to get stable stock speeds. Most people won't have many incentives to spend their time doing it, as opposed to overclockers, but in a few cases it can be a deal breaker: I got the VRMs of a motherboard from imminent meltdown to perfectly safe by undervolting an FX 9370, which still runs stable at stock speeds. I admit it's kind of a best case scenario, because stock voltages were at 9590 levels (1.54v! VRMs at 100C under load), and in an hour or two I had it running with 1.38v (VRMs at 65C under load), and I'm not even sure that's the floor (the 8370E is set to 4.4 as well with less than 1.3v).

 

 

TL, DR: there's like 7 billion people in the planet, so there are very few things that truly never make sense for anyone under any circumstance  

 

[paddy-stone]

6 hours ago, SpaceGhostC2C said:

Then you lack imagination  Sometimes you just don't need the speed and don't want power to go up under any circumstances. An example: I currently have an OCed FX 8370E. I may at some point re-purpose it as a server or something. Going bat to stocks would decrease power draw considerably, but I could still go lower, for example to AM3+ Opteron levels, through underclocking, and it would be perfectly fine for NAS or home server. Yes, I could buy new hardware intended for those function, but undervolting will cost me zero, other than a couple weekend afternoons of undervolting fun (si it's win-win )

K is for changing multipliers - whether upwards (over-) or downwards (under-) is up to you. You are right in that undervolting is still possible, but once you hit the lowest stable voltage you cannot go further by lowering the multiplier. An unlocked CPU would allow for more aggressive undervolting by simultaneously underclocking.

Why would you take away stability? By definition, a successful undervolt is 100% stable, just like a successful overclock. Undervolting is exactly the same as overclocking: finding a stable combination of voltage and clocks. If undervolting was pointless, so would be anything other than overkill voltage for overclocking. Is that really how we overclock?

Moreover, CPU manufacturers will set overkill voltages to make sure every chip works out of the box. So, just like you can try your luck at the silicon lottery and see how far your chip overclocks, you can also play the same silicon lottery and check how low a voltage you can use to get stable stock speeds. Most people won't have many incentives to spend their time doing it, as opposed to overclockers, but in a few cases it can be a deal breaker: I got the VRMs of a motherboard from imminent meltdown to perfectly safe by undervolting an FX 9370, which still runs stable at stock speeds. I admit it's kind of a best case scenario, because stock voltages were at 9590 levels (1.54v! VRMs at 100C under load), and in an hour or two I had it running with 1.38v (VRMs at 65C under load), and I'm not even sure that's the floor (the 8370E is set to 4.4 as well with less than 1.3v).

 

 

TL, DR: there's like 7 billion people in the planet, so there are very few things that truly never make sense for anyone under any circumstance  

 

OK, you're being obtuse deliberately I'm assuming in regard to what the OP actually asked.

 

The OP raised the question below, asking what hardware to get for it, so my answer still stands... you wouldn't buy a chip just to underclock and undervolt it, you would buy a more suitable chip in the first place if you don't have one to re-purpose as you suggested. Yes, if you already have hardware laying around and want a NAS or similar that doesn't need high clocks/volts/wattage then you could go that route. The OP asked what hardware to BUY. You wouldn't if sane buy an i7 6700t and underclock it to such an extent that it's basically crippled the CPU, you would have instead bought a celeron, G series or other lower end CPU for a fraction of the price of the $270+ i7 6700t.

7 hours ago, Okjoek said:

These sort of things are kind of interesting to me. I'm not sure what hardware to get for it though. Linus claims that I'd be better off just getting a lower power CPU in the first place if I wanted lower power. By that logic I should want something like an i7 6700T which is insanely powerful for its 35W TDP, but like my current CPU it's locked so I can't over/underclock, although I've never really cared for overclocking anyways.

 

 

[SpaceGhostC2C]

1 hour ago, paddy-stone said:

you wouldn't buy a chip just to underclock and undervolt it, you would buy a more suitable chip in the first place if you don't have one to re-purpose as you suggested.

 

True. I made a case for underclocking, but not a case for buying to underclock, which was OP's point. I replied to your literal post, taken out of context. So: I have to agree with you, it's hard to think of a scenario in which going for a lower power option is not possible or somehow less convenient than buying and underclocking a higher power one.