AMD Phenom II TDP and underclokcing / undervolting

[droidhacker]

Better late than never, but here's the way it works with CPUs....

Simply put, you're adding more cores, so it will eat more power and make more heat WHEN RUNNING FULL OUT. When you're running a very low load on it, it will hardly use any power and produce virtually no heat, so the situation where you are OK with the X2, i.e. watching a movie or something, it will STILL be silent. When you're doing something really intense, then, if you LET it, it will ramp up speed and get a bit noisy.

Think of it like this;
If you have a car, you will notice that full out at, say, 5000 rpm, then it will be really loud. When you're cruising at 2000 rpm, you can hardly hear the engine at all.

@Thatguy: what are you trying to prove by overclocking with air cooling? That you can make your computer sound like a vacuum cleaner without setting it on fire? You didn't say anything that supports the OEM cooler actually being decent. IT IS STILL A PIECE OF CRAP and it still makes a NASTY noise. A good heat sink with a large and slow fan can cool the CPU *better* while remaining SILENT. Even overclocked.

[crazycheese]

Hi Forum readers!

I have a HTPC (but not deticated - occasional gaming and some tinkering with stuff) setup (OS is Linux / Gentoo) and I'm going to upgrade the CPU (and add 2-4 GBs of RAM). Energy-Power -efficacy is important, because of NOISE. There's just one problem: I can't choose which CPU to upgrade to

You are best suited with Intel ATOM + nvidia ION.
Or intel core i3-540 and similar 1153/5 based.

Of course you can downclock the cores, but current amd energy management is two levels lower than of intel. The noise can be compensated by cooling - its not a problem. But your energy bill cannot. Energy efficient CPU or energy efficient video accelerating GPU are vital.

The mentioned phenom II is good for actual active work - ie recoding ,compiling, calculating etc.

[droidhacker]

You are best suited with Intel ATOM + nvidia ION.
Or intel core i3-540 and similar 1153/5 based.

Of course you can downclock the cores, but current amd energy management is two levels lower than of intel. The noise can be compensated by cooling - its not a problem. But your energy bill cannot. Energy efficient CPU or energy efficient video accelerating GPU are vital.

The mentioned phenom II is good for actual active work - ie recoding ,compiling, calculating etc.

Good luck with playing games on an atom...

[crazycheese]

Good luck with playing games on an atom...

Uh, well, good luck finding next prime number with you Phenom II...
It was kinda not for playing heavy games.. especially if you mean performance games, and those OpenGL4 or WINE DX9+.

You get 6990 or GTX 580(better driver) with Phenom II and you have a monster that when IDLE - chomps triple the amount atom uses at 100% LOAD! Its often cheaper to buy such machine, than to pay exactly the amount in electricity bill at end of the year for using performance machine on such loads!

The cfg is perfect for HTPC and light games only. I don't posses ATOM ION, but a friend of mine does and he reported very good performance in Urban Terror. Means idtech3 or equal games should not be a problem.

[Max Spain]

FWIW I have a P2 965 running at stock clocks 3.4/2.0 @ 1.2375 Vcore, 1.1250 NB. It is stable and uses far less power. Sadly I do not remember how much.

My Atom 330 system uses ~42 - 43 watts with 1 7200RPM drive under a full CPU load. It also takes 8 hours to do 1 of 2 passes on a 1.5 hr SD video encode to Theora.

[renkin]

If you want, you can suck it up and try to wait for bulldozer with their powergated cores and improved TURBOcore

[crazycheese]

FWIW I have a P2 965 running at stock clocks 3.4/2.0 @ 1.2375 Vcore, 1.1250 NB. It is stable and uses far less power. Sadly I do not remember how much.

My Atom 330 system uses ~42 - 43 watts with 1 7200RPM drive under a full CPU load. It also takes 8 hours to do 1 of 2 passes on a 1.5 hr SD video encode to Theora.

Phenom II 965 normal and 1.2v undervolt, without vga.
Normal 1.4 (CPU only / CPU+MB) -> Idle: 15w/109w, Load: 165w /277w
Undervolt 1.2 (CPU only/CPU+MB) -> 1dle 14w/106w, Load: 111w /220w

Atom 330
Normal 330 dualcore (4HT) (CPU+MB) -> Idle: 30w, Load: 41w

Atom 220 on nvidia ion
Normal 220+ion single core(2HT) (CPU+GPU+MB) -> Idle: 16w, Load: 26w

Lets take a version you watch one movie daily - thats 2 hrs/1 day.
365*2= 730hrs/year
Europe best energy cost: 10?/Month + 0,20?*kW/hr
For a year thats: 120? + 0,20?*kW/hrs

For undervolted AMD Phenom II always idling at watching movies vs always full load ion:
0,20?*0,111kW*730= 16?/year
0,20?*0,026kW*730= 3,7? year

Realistically I seriously doubt phenom will idle at movie play. Or igp/discrete gfx card it uses will idle, so its absolutely best case.

ion system cost is around 100?. Do you need it - I think yes if you use around 4hrs a day for 3 years.

[crazycheese]

Phenom II 965 normal and 1.2v undervolt, without vga.
Normal 1.4 (CPU only / CPU+MB) -> Idle: 15w/109w, Load: 165w /277w
Undervolt 1.2 (CPU only/CPU+MB) -> 1dle 14w/106w, Load: 111w /220w

.....
0,20€*0,111kW*730= 16€/year
0,20€*0,026kW*730= 3,7€ year

Uh sorry, I made a mistake above. Thats not 111W, thats 106W.The rest is correct.

[crazycheese]

why not use an amd fusion system?

No video acceleration afaik, or will have to use windows and amd windows driver. Also the thermal management is worser(I think K10 athlon/phenom I-II are on core2duo/quad level), but yes, if the video card would take the task and downclock it won't be a problem.

[crazycheese]

means in REAL for some systems you just don't need video acceleration.

maybe bobcat is to slow but Llano is much faster thats for sure.

Yes, if cpu is ok (and one 2ghz k7 core is already enough for h264) thats no problem.
But then you get a disadvantage of power mgmnt on current selling K10. Intel would already be better with core i+ in long run.If bulldozer comes this may change(I hope it will).

As for gpu, I dont want to touch catalyst, not even for testing. It was plain horror. Maybe I will boot my system on LiveCD to test it soon on vaapi, when I sell amd and get nvidia card(don get me wrong I strong dislike nvidia, but there is no choice from amd). I know that nvidia vdpau works even on ion, and nvidia has been ignorant to some hw support cases, but amd current policy is not acceptable for me now. I dont want windows and I want working hardware(long window, 3d features, stable, hw video decode logic) or the real strong line behind rising opensource that is internally better. Nothing here from AMD, but I don't want to hijack the thread with my situation.