i5-650 with ECC support – the secret low-power server cpu

So after catching some hints here and there, I started to wonder whether the i5-650 might make a really good cpu for a home server.

Coupled with the oddly ambiguous Intel Ark i5-650 entry which notably doesn’t say “No” to ECC support when other CPU’s have an entry for “ECC Memory Supported” that usually states “Yes” or “No“, I decided to take a gamble, and bought one off fleabay.

And lo and behold, the i5-650 does support ECC memory on a compatible motherboard.  I did my tests on a Supermicro X8SIL I already had to hand, which incidentally is a great little mATX motherboard with some really good expansion potential – but more on that another time!

So with verification of the ECC support done, it makes the i5-650 a great pick for a low-power consuming home server for the technically minded.  Why is that?  Simple.. it has these attributes:

  • 32nm process and only 73W TDP – so its not power thirsty
  • low voltage idle state (0.65V)
  • 3.2GHz dual core with hyperthreading, so not a slouch
  • Supports VT-x and VT-d so good for virtualization
  • Supports the AES-NI instructions for encryption throughput
  • Supports ECC

To verify, I checked the output of dmidecode under Centos 6.4, and here’s what it said:

# dmidecode 2.11
SMBIOS 2.6 present.

Handle 0x0008, DMI type 5, 24 bytes
Memory Controller Information
    Error Detecting Method: 64-bit ECC
    Error Correcting Capabilities:
        Single-bit Error Correcting
    Supported Interleave: One-way Interleave
    Current Interleave: One-way Interleave
    Maximum Memory Module Size: 4096 MB
    Maximum Total Memory Size: 16384 MB
    Supported Speeds:
    Supported Memory Types:
    Memory Module Voltage: 3.3 V
    Associated Memory Slots: 4
    Enabled Error Correcting Capabilities:
        Single-bit Error Correcting

The key bit is the bottom two lines.  Error Correction is only enabled if the memory controller, motherboard, and memory itself all support ECC.

My own plan is to run a custom Xen environment based on Centos’ newly released support for Xen (yay! no more building custom rpm packages – hopefully a precursor to Redhat re-adopting Xen?).  However, the cpu would also make a great basis for a home ESXi lab.  Either way, the fact that it supports ECC and also VT-d will open up some options for configuring this next iteration of my home server.  I’ve picked up some other goodies to add to the experiment, and will post them another time too.

So how low power a server are we talking?  I’ve got a cheap power meter I picked up at Aldi, and I’ve been running some tests with different LGA 1156 cpu’s (i5-750, Xeon x3450, i5-650) on the exact same setup, so I’ll make a post about that next time.  But for now, here’s a teaser:

A basic i5-650 system idling at 29.2 watts

A basic i5-650 system idling at 29.2 watts

This is measured on the Centos live-DVD desktop, and includes:

  • 4x4Gb Kingston ECC memory
  • 160Gb Intel X25-M SSD
  • Antec case fan on molex connector
  • Active network port
  • A not-hugely-efficient Antec VP-350 PSU
  • Microsoft PS/2 keyboard & USB optical mouse

6 thoughts on “i5-650 with ECC support – the secret low-power server cpu

  1. I have a foxconn P55MX and H55MS motherboard, i build a i5 dualcore and a i5 quad core in to them.
    I got my eye on DDR3 4GB slots , for server use. ( Samsung 2x 4GB = 8GB KIT DDR3 RAM 1333 Mhz PC3-10600R ECC REG DIMM)

    these are pretty cheap.
    My question does these motherboard support these ECC memory?

  2. Thanks for this, too bad that the 1156 socket chipset only supports 1x 16x or 2x 8x. Not enough expansion to do what I need to do.

    • Yeah, the memory config options were amusing trying to wrap my head around.

      I ended up with 32GB of unbuffered x8 ECC which works fine with the i5-650 – so if I upgrade to a newer 1155 or 1150 Xeon I can continue to use the same memory. For now I’m running an LGA1156 Xeon tho’, despite the lack of AESNI, having 8 threads is handy.

      • Hi, thanks for the info!

        Did you get 32GB of UDIMM ECC to work on the XSIL with an i5-650? The board manual says you can only use up to 16GB of UDIMM ECC or 32GB of RDIMM ECC.

        One a different note, I bought 16GB (4 modules of 4GB 4RX8 RDIMM), but I can’t make it work with my i5-650 on a X8SIL-V. I get an infinite duration beep and a flashing yellow led. The blinking LED means unsupported memory, but I don’t know if the beep means anything else. The memory is listed as supported on SuperMicro’s website (MT36JSZF51272PDZ-1G1F1). I think the issue might be that RDIMMS are only supported with Xeon processors – can you confirm that? The website does say this: * Dual Core processors of Ci5, Ci3 and Pentium: support ECC UDIMM only. I guess that applies to i5s as well…

        • Later but still…here is my answer:

          I5-650 does not support RDIMM!!!
          You can only use UDIMM (ECC) or UDIMM (non-ecc).

          Only Xeon X34x0 Series does support RDIMM with 3450 Chipset (and only if the board manufacturer added the support in the bios).

          Core i5 and i3 does not support RDIMM!!!!

          • Also late:

            X8SIL-V does not support Clarkdale i5 with old x8sil-v with revision v1.0 and v1.01.

            You need rev 1.02 and additional bios update for Clarkdale i5 support.

            Also…..i5 does not support RDIMM (only xeon does).

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