1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

The truth about CPU power consumption

Discussion in 'Processors and Motherboards' started by sub.mesa, Dec 30, 2010.

  1. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    There is truth to the thought that Intels chips all have very good idle and they are not far apart when idling. However, the L chips are also heavily binned and have lower vcore by default than non-L chips. Yes you could probably undervolt and underclock your i5 and get to a similar place...

    Frankly 1/6 *80w gets you 13w ... so these V3 chips scale pretty darn well.

    As I have a 1.6ghz 1220v3 as well as quite a few other v3 chips ... I could do some testing in the coming weeks.
    Suggestions as to accurate power meters?
     
    #21
  2. HellDiverUK

    HellDiverUK Active Member

    Joined:
    Jul 16, 2014
    Messages:
    285
    Likes Received:
    49
    I was under the impression the Haswell power states were only in standby/sleep.
     
    #22
    Patriot likes this.
  3. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
     
    #23
  4. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    I don't know... but frankly I am not in the mood for digging through intel white papers right now...
    I would be surprised if it was not more complicated.

    It may be that there are only a few P states... but how they interact with the C-states and T-states ... creates the complicated mess that it Intel's dynamic frequency and power usage.

    Does anyone have powermeter suggestions for doing some in-depth analysis?
    I don't think a killawatt is going to be as accurate as we desire for low end systems... I also may have damaged mine trying to measure a 1480w load once...

    @HellDiverUK FSP 1u unit model number?

    I think it is time to have some fun with power draw numbers.
     
    #24
    Last edited: Feb 19, 2015
  5. HellDiverUK

    HellDiverUK Active Member

    Joined:
    Jul 16, 2014
    Messages:
    285
    Likes Received:
    49
    FSP150-50GUB
     
    #25
  6. NeverDie

    NeverDie Active Member

    Joined:
    Jan 28, 2015
    Messages:
    299
    Likes Received:
    25
    @Patriot: How's it going with the powerdraw numbers?
     
    #26
  7. mrkrad

    mrkrad Well-Known Member

    Joined:
    Oct 13, 2012
    Messages:
    1,188
    Likes Received:
    43
    So how stable are those power savings modes versus PCI-E versus crashing? Back in the X5600/5500 series we had to peg power save to DISABLE/MAX POWER USAGE to achieve stability and maximum pci-express performance with esxi?

    Has this front improved much?
     
    #27
  8. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    Still need to get a lower power psu to get good load lines... seasonic makes like a 300w gold... thats the best I have found so far.
    Also have not dropped the $250+ to get a power analyzer... The killawatts are not accurate under 60w.

    But I do have a e3-1220l v3 1.6ghz 16w chip I want to test and a E5-2630L v3 ...
     
    #28
  9. NeverDie

    NeverDie Active Member

    Joined:
    Jan 28, 2015
    Messages:
    299
    Likes Received:
    25
    Wouldn't measuring voltage and current with a multimeter get you the answer?
     
    #29
  10. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    2 values continually fluctuating under load that have to be calculated? no thanks. I need a RMS power meter that sits between wall and psu.
     
    #30
  11. NeverDie

    NeverDie Active Member

    Joined:
    Jan 28, 2015
    Messages:
    299
    Likes Received:
    25
    I notice some PSU's (e.g. the Corsair RM450 and others) provide power data and even graph it:
    [​IMG]
    Not sure about accuracy, but if you view it as a combo it might be thrifty.

    Brand new an RM450 is $90.
     
    #31
    Last edited: Mar 13, 2015
  12. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    Corsair link has some interesting issues. hmmm I will look into it.
     
    #32
  13. NeverDie

    NeverDie Active Member

    Joined:
    Jan 28, 2015
    Messages:
    299
    Likes Received:
    25
    I'll be interested in what you find out. I ordered a refurbished RM450 that should arrive next week sometime. I didn't buy it for the Corsair link, per se, but I noticed it's part of the package.
     
    #33
  14. Patriot

    Patriot Moderator

    Joined:
    Apr 18, 2011
    Messages:
    987
    Likes Received:
    511
    Link support.... you probably still have to buy the $30-60 link module.

    Also... Not terribly accurate given this review.
    JonnyGURU - Corsair HX750i 750W
     
    #34
    Patrick likes this.
  15. NeverDie

    NeverDie Active Member

    Joined:
    Jan 28, 2015
    Messages:
    299
    Likes Received:
    25
    That's a pity. Great review though. I wonder if Corsair's "flagship" AX760i would be any better?
    Corsair Power Supply Units — the state of the art PC Power Supplies for reliable delivery of clean power under imperfect conditions
    The table lists the AXi series as having "advanced" Corsair Link support, versus merely "Intermediate" support for the HXi series, which is what JohnnyGURU reviewed. At the bottom the chart claims the AXi series is designed for "system monitoring and control," but isn't making the same claim as the design target for the HXi series.

    I realize those are rather shallow reasons for optimism, but who knows? Maybe. I would think the DSP that's in their AXi (but apparently not in their HXi) would need accurate measurements if it's to be of any value.
     
    #35
    Last edited: Mar 13, 2015
  16. T_Minus

    T_Minus Moderator

    Joined:
    Feb 15, 2015
    Messages:
    4,633
    Likes Received:
    821
    Which unit were you looking at? I want to get something more accurate than the Kill-A-Watt too.
     
    #36
  17. Dajinn

    Dajinn Active Member

    Joined:
    Jun 2, 2015
    Messages:
    513
    Likes Received:
    72
    So are Xeon L5640 CPUs a waste for home use? Is that a take away I can have from this discussion? lol
     
    #37
  18. Patrick

    Patrick Administrator
    Staff Member

    Joined:
    Dec 21, 2010
    Messages:
    8,383
    Likes Received:
    2,264
    Westmere-EP low power means a lot more than it does now in terms of idle power consumption. I do like the L5640's for home use still.

    Intel's power management has gotten ever increasingly more complex hence the move to put more of those components on die. Newer chips do have very similar idles.
     
    #38
  19. vrod

    vrod Member

    Joined:
    Jan 18, 2015
    Messages:
    55
    Likes Received:
    11
    So it's a while since anyone posted anything in this topic, but have people made improvements? Are there anyone else out there than me with "custom case" designs?

    I'm currently netbooting all my servers through PXE and anything else than my central storage box are running in my own custom "shelf" cases. Basically a 2U shelf with a plastic spacer between the shelf and the board.

    Board is attached with zip ties and beside is the either 2U EPS Psu or TFX psu. The plastic plates have some extra spacing on the side so the board can't get in any metallic contact. Then just a couple of low power, self regulating arctic cooling fans who keeps a decent airflow depending on temp.

    Works really well and the depth of the shelves enables me to put one in the front of the rack and one in the rear (front one just rund airflow in reverse to match rear). IO panel is facing outwards so easy enough to attach vga, network or something else.

    With a S2600cp4 board coupled with some 2670's, I can get down to 40w idle. It's really beneficial for me as well because I can disable power hungry stuff like the ahci controllers and such.

    The density also makes it a good solution for cost savings and I'm currently trying to draft a 1U solution which will enable me to have 4 2670's in 1U. :D

    Best of all is that it's a lot cheaper than normal rack cases!
     
    #39
    pgh5278 likes this.
  20. T_Minus

    T_Minus Moderator

    Joined:
    Feb 15, 2015
    Messages:
    4,633
    Likes Received:
    821
    @vrod

    Pictures Please :) Sounds interesting.
    Maybe a new thread for your DIY Builds :)
     
    #40
Similar Threads: truth power
Forum Title Date
Processors and Motherboards Power Consumption SM X8DTH-IF L5639 --> X10SRL-F E526xx v3? Jan 30, 2017
Processors and Motherboards Power Consumption Help Jan 22, 2017
Processors and Motherboards Any specific requirement for a Mobo to read power stats from the PSU? Jan 3, 2017
Processors and Motherboards HDD (Molex) power on mainboard Dec 30, 2016
Processors and Motherboards Power Costs - Upgrade Worth It? Dec 19, 2016

Share This Page