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AMD Phenom II TDP and underclokcing / undervolting

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  • AMD Phenom II TDP and underclokcing / undervolting

    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

    Currently it is running on AMD X2 4850e. The temperatures are VERY good on this 45W processor with the aforementioned exhaust fans just next to the Nexus Ninja Mini, even with full load it never gets above 50?C (in the summer maybe just there - now that the sun isn't heating this apartment to the 32?C ambient temperature, I really need to work getting the cores to 46?C).

    I have two processors currently in mind (that are available here):

    AMD Phenom II X4 910e (2.6GHz, @65W TDP)
    AMD Phenom II X6 1055T (2.8GHz, @95W TDP)

    The price difference is negligible. I think that with the current cooling solution I'd have no problems cooling a 65W processor, but with a 95W TDP processor, I might run into problems. But, I read one can LOWER the multiplier on a non-BE Phenom II - so, if the cooling is insufficient, I could lower the multiplier on the X6 so that I'd run (when running at maximum speed) on 2.6GHz? If that is the case, I'd go for the extra two cores - or maybe even a 125W Phenom processor?!??

    So, any experience with underclocking / undervolting Phenom II's? Is there a lot of TDP to gain, say, undervolting the aforementioned 1055T? Or a 125W one (either a X6 or a higher speed X4)? Do these new processors have any stability issues when undervolting / underclocking?

    Cheers!

  • -hanky-
    replied
    First of all: Although we definitely don't have the same opinion, it's a very interesting discussion.

    Just some remarks to your posting:

    But he will need a new motherboard. I agree that current AMD systems are not energy efficient, but they are "bang for the buck". Unfortunately, dependent on where he lives, the energy bill bond to AMD will remove any advantage in the mid run. This is if he uses no video acceleration. Things will change with nvidias (blobby blob) VDPAU.
    I have to confess, i thought that he already uses a nvidia card at the moment, but i just checked his first post and he didn't mention it. So he would have to buy board + cpu+ (cheap) graphics card. If that's the case he should in fact consider to just buy a new graphics card instead of upgrading the cpu.

    3. He gets ION system and keeps the hardware. His energy bill may go up a bit (30W full load, cmmon) or may go down a bit (using htpc for media instead of main rig) and does not need to mess his computer with anything HTPC related. Price is 100$
    If he wants to keep (and use) his current hardware, he will not only have to buy a an ION system (cpu + board), but also ram, hdd, tower, power supply. I wouldn't do that.

    4. He gets an intel system and sells his own. 200-250 compensated by 70-40 if he manages to sell his old system. I don't know how good intel gfx drivers are. Sandy bridge gfx is still unusable in linux right now with 1156 hardware being already abadoned and 13xx socket eating up same amount of energy in idle as AMD. Though his energy bill goes down to some good extent in the long run, true, he still will have one machine.
    I don't know much about the intel gfx drivers either, but shouldn't the rest of the sandy bridge hardware be supported by a current kernel? He would require a graphics card anyway, because afaik you can only use integrated graphics with a core i3.

    Yes, its efficient silent box. You can compile on it 24h/7 or just leave it for 2 days for basic setup - really not a problem, you won't upgrade further anyway and even then he can unmask only the critical packages. Or he can use gentoo-based precooked distro (calculate, sabayon xbmc etc). Or even non-gentoo precooked media-center distro. I had a friend that used Slackware on single core atom, he didn't complain. Eats barely, performs barely, heats barely, small package.
    Well, you should express it like this: You have to compile 24/7 with such a system... No, seriously: Especially if you do such cpu intensive things like compiling, all the advantages of an atom system are gone. It consumes less power idle and under load, but you may not forget that a hexacore or a core i5 is more than 7-8 times faster. Do the math - an atom cpu is much less energy efficient under this circumstances.
    If the thread starter doesn't need more power, he should just keep his current setup - it is about two times faster than an atom system and has low power consumption, too. If he needs more power, an atom system is the wrong choice.

    Of course he could change board, cpu and switch to precompiled packages, too, but he would still spend money to actually downgrade his system, which frankly makes no sense to me.

    Anyway, i should get some hours of sleep now

    -hanky-

    P.S.: Who in germany has a power plant in the backyard?

    Leave a comment:


  • crazycheese
    replied
    Originally posted by -hanky- View Post
    I don't think that Atom/ION/Zambezi is too slow to watch high definition movies (at least ION isn't, UVD under linux is just a pain in the ass at the moment, no idea if or when it gets better).
    I agree.

    Originally posted by -hanky- View Post
    I just said that it makes no sense for him to change to such a system if he wants to upgrade, because clearly even his 4850e is faster than the fastest available atom cpu (or a comparable cpu from AMD, like the e-350).

    I also didn't ask him to buy a new cpu+motherboard, i just mentioned that it might be worth a thought.
    But he will need a new motherboard. I agree that current AMD systems are not energy efficient, but they are "bang for the buck". Unfortunately, dependent on where he lives, the energy bill bond to AMD will remove any advantage in the mid run. This is if he uses no video acceleration. Things will change with nvidias (blobby blob) VDPAU.


    Originally posted by -hanky- View Post
    Anyway, here some interesting test results (sorry, it's in german, but I think the graphs speak for itself):

    http://www.tomshardware.de/32nm-Sand...-240701-7.html
    Ich hab sogar etwas noch besseres =) Sieh mal:
    http://techreport.com/articles.x/18448/4 bes. Energy per Task Graph.
    http://phoronix.com/forums/showthrea...ger&highlight= Reasons for K10 inefficiency and reason for AMD Athlon II x4 being rated at Phenom' II 1.4v Vcore, instead of pretty stable 1.2v


    Originally posted by -hanky- View Post
    So I think it's definitely worth thinking about spending more money and take the Intel system.
    If energy cost in his country is rather cheap - no, if its Germany - pretty much yes, but if he lives in Germany and has power plant in the backyard - again no (don't ask where I got his ).

    Originally posted by -hanky- View Post
    Of course, if he doesn't need more performance anyway, there is no need to upgrade. Then he should keep his current cpu and buy a cheap geforce card, like the GT430 as you mentioned.

    If he wants and/or needs more performance then he should consider the Core i5 as a possible alternative to an AMD hexacore.

    Nevertheless, in both cases there is simply no need for an ATOM-like system.
    1. He upgrades to hexacore or similar and downclocks it a bit. He gets better performance for existing system, but larger energy bill as well. The investment is around 150$
    2. He keeps the hardware and gets the card with HW accel(thats nvidia blobby blob). He gets a bit bigger energy bill, a dependence to proprietary driver; but rather small investment(50$).
    3. He gets ION system and keeps the hardware. His energy bill may go up a bit (30W full load, cmmon) or may go down a bit (using htpc for media instead of main rig) and does not need to mess his computer with anything HTPC related. Price is 100$
    4. He gets an intel system and sells his own. 200-250 compensated by 70-40 if he manages to sell his old system. I don't know how good intel gfx drivers are. Sandy bridge gfx is still unusable in linux right now with 1156 hardware being already abadoned and 13xx socket eating up same amount of energy in idle as AMD. Though his energy bill goes down to some good extent in the long run, true, he still will have one machine.

    Originally posted by -hanky- View Post
    By the way, you really want to recommend an ATOM/ION system to someone using gentoo?
    Yes, its efficient silent box. You can compile on it 24h/7 or just leave it for 2 days for basic setup - really not a problem, you won't upgrade further anyway and even then he can unmask only the critical packages. Or he can use gentoo-based precooked distro (calculate, sabayon xbmc etc). Or even non-gentoo precooked media-center distro. I had a friend that used Slackware on single core atom, he didn't complain. Eats barely, performs barely, heats barely, small package.

    Leave a comment:


  • -hanky-
    replied
    Originally posted by crazycheese View Post
    If you think Atom/ION/Zambezi is too slow you either using it not as HTPC, or watching 9000x18000 movie.
    I don't think that Atom/ION/Zambezi is too slow to watch high definition movies (at least ION isn't, UVD under linux is just a pain in the ass at the moment, no idea if or when it gets better).

    I just said that it makes no sense for him to change to such a system if he wants to upgrade, because clearly even his 4850e is faster than the fastest available atom cpu (or a comparable cpu from AMD, like the e-350).

    I also didn't ask him to buy a new cpu+motherboard, i just mentioned that it might be worth a thought.

    Anyway, here some interesting test results (sorry, it's in german, but I think the graphs speak for itself):

    http://www.tomshardware.de/32nm-Sand...-240701-7.html

    We are talking about 26W difference already in idle (2500k vs 1100T). And that's without any undervolting. Under load there is a difference of more than 100W (!).

    So I think it's definitely worth thinking about spending more money and take the Intel system.

    Of course, if he doesn't need more performance anyway, there is no need to upgrade. Then he should keep his current cpu and buy a cheap geforce card, like the GT430 as you mentioned.

    If he wants and/or needs more performance then he should consider the Core i5 as a possible alternative to an AMD hexacore.

    Nevertheless, in both cases there is simply no need for an ATOM-like system.

    By the way, you really want to recommend an ATOM/ION system to someone using gentoo?

    Leave a comment:


  • crazycheese
    replied
    If you think Atom/ION/Zambezi is too slow you either using it not as HTPC, or watching 9000x18000 movie.

    Leave a comment:


  • crazycheese
    replied
    Core i5 1156 is a goner. Core ix-xx00 (sandy bridge) is very buggy in current revisions, it works good only on w7 and only on some applications. The guy has already good system and you ask him to sell it (cpu+mb) and buy equivalent system that is more expensive (,buggy) and still eats a LOT of electricity compared to ION/Zambezi(provided AMD ever fixes UVD). Of course core-i/i-xx00 are more energy efficient, but he already had them and if you undervolt the usage will drop to 85-90 watt idle vs 70-80 watt idle of intel - it will not pay itself back. Better get dedicated HTPC with small usage or get a basic discrete gfx card that can accelerate video (gf 430 etc)

    Leave a comment:


  • -hanky-
    replied
    Originally posted by crazycheese View Post
    Or even better, buy quad amd magny cours and 24 Gigs of registered ECC ram - you will able to play over 3000 movies at once!
    Regarding to the first post, the thread starter wants to upgrade his current system and therefore mentioned two possible options:

    AMD Phenom II X4 910e (~ 125 ?)
    AMD Phenom II X6 1055T (~ 145 ?)

    No matter which of both he would take - they would both be significantly faster than your idea, which iirc would be an atom/ion system (which is incredibly slow in comparison, just to make it clear again).

    A Core i5 would be oversized, but as i said it would also consume less power and stay cooler - not to mention that it is faster. So there would be absolutely no disadvantage, except that he would have to buy a new motherboard (ok, which isn't available at the moment ).

    Nevertheless, i don't see why he should literally downgrade to an ion system when his first intention was to upgrade...

    Don't get me wrong, there are several occasions in which an atom/ion combination fits - but not this one, except he accepts to buy new hardware that runs even slower than his current setup.

    -hanky-

    Leave a comment:


  • crazycheese
    replied
    Or even better, buy quad amd magny cours and 24 Gigs of registered ECC ram - you will able to play over 3000 movies at once!

    Leave a comment:


  • -hanky-
    replied
    Hi,

    if you want a silent, cool and power-saving system and if you are willing to invest some money into a new motherboard, too, you maybe should just take one of the new Core i5 in combination with a 1155 motherboard.

    For example, the Core i5-2500 easily outperforms the fastest AMD hexacore available at the moment (at least regarding to cpubenchmark.net), it consumes significant less power (especially under load) and stays cooler. For almost the same price!

    Nevertheless, i happen to use an undervolted (and unlocked) Phenom II system

    Here is some data you might be interested in:

    System specs:

    Phenom II X4 B50 (Phenom II X2 B550, all cores unlocked) @ 3.1 Ghz
    Scythe Samurai ZZ
    MSI 785GM-E51
    Geforce 450GTS
    3x HDD
    2x optical drive

    I use "k10ctl" to undervolt the cpu for all available p-states (800 Mhz, 1900 Mhz, 2400 Mhz, 3100 Mhz).

    It runs stable with the following settings:
    800 Mhz @ 0.8V
    1900 Mhz @ 1.0 V
    2400 Mhz @ 1.075V
    3100 Mhz @ 1.275V

    Unfortunately, after unlocking, the thermal sensors for coretemp don't work anymore, so i only have values for temp1:

    idle: ~ 36-39 ?C / fan @ ~ 500 rpm
    load: ~ 55-58 ?C / fan @ ~ 1400 rpm


    Power consumption (for the whole system, including hard drives, optical drives, graphics card) according to my measuring device (a rather cheap one, so might be inaccurate):

    idle: 70W
    load (4x mprime -t): 170W

    If you have any more questions, feel free to ask!

    -hanky-

    Leave a comment:


  • crazycheese
    replied
    http://geizhals.at/a613148.html
    uATX package

    review: http://www.overclock3d.net/reviews/c...ro_micro_atx/1

    "In a nutshell, the Asus E35M1-M PRO is everything a typical Atom Dual Core + ION offering is, but noticeably better. Those who wish to use the board as a HTPC or NAS box will be pleased by the flexible storage options and the passive/low noise operation. Also we have shown that 1080p is doable with no trouble at all."

    That was when using windows as os.
    On linux this comes to nvidia vs amd... you understand.

    Leave a comment:

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