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    It would be good if we could list cpu's and if power saving was possible with them or not. For example the Celeron Processors and my Intel Pentium D 820 CPU do not support SpeedStep (Intel's version of AMD's Cool'n'Quiet Technology) so the proccessor will not go to a reduced power state when there is no load on the server. I just wish I knew that before purchasing my D 820. Can you add any more?
    Wednesday, October 3, 2007 8:31 AM
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Answers

  • Intel's processor charts show which CPU's support SpeedStep.

     

    Pentium D 830 or above has SpeedStep. I suggest upgrading and selling your 820 on eBay.

    Wednesday, October 3, 2007 5:24 PM

All replies

  • Intel's processor charts show which CPU's support SpeedStep.

     

    Pentium D 830 or above has SpeedStep. I suggest upgrading and selling your 820 on eBay.

    Wednesday, October 3, 2007 5:24 PM
  •  

    Hi there. The reason because why the 820 (and 805, 915 and 920, for that matter) don't have EIST (the name SpeedStep got a while back) is because they already are operating at the minimum specifications for SpeedStep. If you look closely, an 830 - or any other 8x0 CPU for that matter - will essentially become an 820 when EIST is enabled. Same thing for the 900 series: 915/920 is the lowest possible speed the CPU can have while activating EIST.

     

    Celerons, on the other hand, never had EIST enabled. Mostly because they are low-wattage CPUs (so they don't have to be that careful on that department), but also because it probably makes them cheaper to make.

     

    If you, however, want low consumption servers/PCs, then you shouldn't be looking at the 300, 500, 600, 800 or even 900 CPU series from Intel. Those are Netburst-based parts, which means they will heat up A LOT, even if EIST or C1E (for those parts that support it) are active. You are MUCH better getting low-wattage AMD CPUs (I don't buy AMD, so I can't help you there, though I know there are very good low wattage CPUs from the company), or "Core"-based Intel CPUs (MOTHERBOARD COMPATIBILITY CHECK, PLEASE!), especially from the 2000 and 4000 series. These have VERY low consumptions, especially when on full load (12W idle for anything with an L2 stepping, 8W idle for M0). And, if you don't need dual cores, you can get a 400 series Celly.

     

    In a recent review I read, the E2140 Pentium Dual Core would work fine even without a working CPU fan. The 4xx Cellys even have all-alluminum (instead of alluminum-copper) half-height heatsinks, so those are some COLD CPUs, even without EIST.

     

    What I would recomend is that you fiddle with C1E (and its equivalent for AMD CPUs) to get an even lower power consumption. My E6400 is perfectly capable of working with much lower voltages than default ones, so I get a cooler CPU AND lower power consumption at the same time. If you need help with that, drop me a line.

     

    Ok, so that leaves us with the list you wanted. I can help with the Intel list, but someone else would have to step in for the detailed AMD one, because I'm not very familiar with AMD parts.

     

    Anyway, some general guidelines:

    - get a 65nm (or lower, though 45nm parts are not yet available) technology based CPU, since the smaller the manufacturing tech, the lower the power consumption (for equivalent parts ONLY, of course);

    - get a CPU with variable voltage input (I think CnQ always had that, and C1E Intel parts have it too)

    - if available, get a low-wattage CPU, since those are made with power consumption in mind.

    - use software to control your CPU speed and voltage, so you can get the most out of it.

     

    That said, here it goes:

     

    Intel "Power Saving CPU list"

    - 600 and 900 series, for those of you who can't get Core-based parts because of motherboard incompatibility. They all have EIST (except 62x, 915 and 920), and some also have C1E. Preferred over the 500 and 800 series, because they are 65nm parts (500 and 800 are 90nm);

    - 65nm 300 series Cellys, which can be recognized because they all have 512KB of on-board L2 cache, instead of 256KB from 90nm Cellys;

    - ANYTHING Core-based, except maybe Extreme Edition and Quad-Core CPUs, is better than Pentium 4s or Pentium Ds, so these would be the way to go if you want low consumption (and increased performance too over P4s, but that's another theme), but even so, the best ones for power consumption are 400 series Cellys, E21xx Pentium Dual Cores and E4xxx Core 2 Duos. M0 stepping ones (you have to check, but E2180 and E4500 have ONLY M0 steppings) are better on idle power consumption, but even L2 ones (everything else in these series, and some E6300 and E6400) are good at that.

     

    Hope this helps, and sorry for the huge post.

     

    Cheers.

     

    Miguel

    Sunday, October 7, 2007 1:47 PM
  • You can search AMD's dektop line at http://products.amd.com/en-us/DesktopCPUFilter.aspx (It is interesting to note that the 35W CPUs are all 90nm) and their mobile line at http://products.amd.com/en-us/NotebookCPUFilter.aspx.

     

    Intel processors can be found at http://processorfinder.intel.com/Default.aspx but you can't drill down by wattage.

    Monday, October 8, 2007 1:32 AM
  • AMD just launched some new power-saving 45W CPU's, and as reported by ars technica, they should offer excellt performance per watt for WHS.
    Tuesday, October 9, 2007 12:39 PM
  •  Bezalel Geretz wrote:

    You can search AMD's dektop line at http://products.amd.com/en-us/DesktopCPUFilter.aspx (It is interesting to note that the 35W CPUs are all 90nm) and their mobile line at http://products.amd.com/en-us/NotebookCPUFilter.aspx.

     

    I think the reason for all 35W AMD CPUs being 90nm parts has something to do with the fact AMD just recently (less than a year) launched the first 65nm part. It takes a while for the manufacturing process to develop to the point where you can lower operation voltages and still keep the CPU operating with stability. Just look how long it took AMD to deliver 35W 90nm parts... But they will get there, and it shouldn't be too long for 65nm parts to reach 35W or even lower TDPs.

     

    Also, Intel suffers from the same issue. The Core 2 Duo line of CPUs was launched more than a year ago, and just now, when the 45nm parts are appearing, we can have more power-efficient steppings on 65nm parts... Just check the new G0 and M0 parts, which were launched a couple of weeks ago.

     

    As for the mobile parts, it sure is a good idea, since they are all very low wattage parts. But keep in mind MoDT (Mobile on Desktop) motherboards are VERY hard to find, and VERY expensive. Ditto for mobile CPUs...

     

     Bezalel Geretz wrote:

    Intel processors can be found at http://processorfinder.intel.com/Default.aspx but you can't drill down by wattage.

     

    I can help there.

     

    First of all, let me say that Intel's TDP definition is kind of weird. I think it has something to do with maximum dissipated heat at the center of the heatsink, and that's why ALL C2D parts (except maybe the Extreme Edition CPUs) are 65W. Top-of-the-liners may have a slightly higher TDP (C2Q, for instance, have 95W and 105W, if memory serves me right), but that doesn't mean that's their power consumption. Especially because usually higher-performance parts are also more refined ones, often resulting in lower power consumption than the "younger brothers" (that was right at least when comparing first generation E6700s and E6400s...).

     

    That being said, lower-end parts can still be much more power efficient than high-end parts, especially when idling. Right now there are three (for C2Ds, I'm not really sure about C2Qs and EE CPUs) "idle TDPs" for Intel CPUs: 8W, 12W and 25W. M0 stepping parts (only E21xx and E4xxx, for now) have 8W idle wattage; L2 stepping parts (E21xx, E4xxx and second generation E6300/E6400) have 12W idle wattage; B3 stepping parts (first generation E6300/E6400, and pretty much every other C2D-based CPU, AFAIK) have 22W idle wattage.

     

    There are also the G0 parts, but those only drop the maximum TDP, not minimum, from B2/B3 stepping parts.

     

    In short, the most power-efficient Intel CPUs you can get now are M0 E21xx and E4xxx parts. Or a Celly, but that's a single core CPU... hehe

     

    Hope this helps.

     

    Cheers.

     

    Miguel

     

    [EDIT] Well, it seems I must spend more time on Intel's Processor Finder page. A quick look at it just showed me that G0 Core 2 Duo Parts also have 8W idle wattage (including the E6850!); and there are also some B2 C2Ds (B3s are Quads) wich have 12W idle wattage. Great news for CPU power consumption concerned people Big Smile [/EDIT]

    Sunday, October 14, 2007 9:39 AM
  • Hi there,

    I know this thread is somewhat old, but I found it really interesting, and I would like to know how things look now, as I'm trying to build a file server (not a NAS or similar), and I would like it to be as quiet as possible (possibly completely silent)  and as power saving as possible, so I'm looking for i.a. cpus with low power consumption.

    I hope this post will be seen by the right people.. :-)
    • Edited by xavis Wednesday, September 24, 2008 3:11 AM Errors
    Wednesday, September 24, 2008 3:08 AM
  • I'm using one of the new Conroe based Celerons in my WHS I just built, it idles at 22c and has a rated TDP of 35w. WHS is snappy so I'll assume for a basic file server this is more than enough. If you can find the right enclosure you could get one of the new Intel Atom CPUs (I believe a TDP of around 6w), but finding a proper enclosure for that board might be tough.
    Wednesday, September 24, 2008 5:25 PM
  • I think , within reason, regardless of what CPU you use, the hard drives and quantity may be a "hot" point. I am using 3 x SAMSUNG HD501LJ's running at 30C  and the way they are shoehorned into a SATA backplane, means they will run hot unless force air cooled. This introduces noise. So even if you have cool running CPU's, you might have noise from other sources. I'm running an E2180 on an MSI  945 GCM5 motherboard as I want the "brute" capability of running software, rather then a weak powered server that takes all day to perform. (sound like my grandson!!).
    regards,
    Wednesday, September 24, 2008 11:05 PM
  • 30c is well within spec for any modern hard drive (most of which are rated for a max of 55c or higher), so that doesn't seem too bad.
    Thursday, September 25, 2008 12:15 AM
  • Wow, a lot of stuff I don't know anything about! I'm not sure of the abbreviation "WHS"? I have thought of an Atom, but it bundles with the 945GC Express chipset, which apparently isn't that power saving.

    Concerning harddrives, I'm thinking of 2 -maybe 3 - rather large disks (e.g. the new Seagate 7200.11 1.5 TB). I'm awayre of the risk of noise from other sources, which is also why I'm looking for an almost-silent PSU. Any suggestions? And please don't say Pico, as I'm afraid it won't be enough - especially if I decide to include more disks, or to make it work more than initially planned. But for now the only function of it is to run a few applications - nothing 'hardcore'.
    Tuesday, September 30, 2008 8:46 AM