As I mentioned earlier, all of the IVB-E launch SKUs ship fully unlocked. Intel offers multipliers up to 63x for you to choose from when overclocking. Like SNB-E before it, IVB-E supports specific BCLK straps (125MHz and 166MHz, in addition to 100MHz) for those overclockers looking to get the absolute most out of their chip. At these overclocked BCLK frequencies, PCIe and other buses are properly divided down so they aren't overclocked (although if you increase the BCLK frequency beyond these strap defaults you will once again be overclocking other buses that derive their frequencies from BCLK). In practice, the cleanest/simplest way to overclock any K-series SKU is by increasing the multiplier.

In our review of the Core i7-3960X I managed a maximum stable overclock of 4.6GHz. I've been told to expect a similar average for Ivy Bridge E. Using Intel's RTS2011LC self contained/closed loop liquid cooling solution I could get into Windows 8 as high as 4.6GHz at 1.42V, however my testbed wasn't stable through all of my tests at that frequency/voltage combination. Moving to higher voltages didn't help, so I had to back down on frequency. I ultimately ended up perfectly stable at 4.3GHz, with 4.4 - 4.5GHz possible with better cooling. The added power needed to hit these frequencies was substantial. I measured a 58W increase in average load power consumption at 4.3GHz/1.4V.

From what I've seen, my sample is a bit on the disappointing side in terms of overclockability. Either way, it doesn't look like you're going to be seeing overclocks significantly higher than what was possible with SNB-E.

Power Consumption

With the 4960X delivering around 5% better performance than the 3970X, the only remaining question is how much more power efficient the move to 22nm made things. Using the same ASUS X79 Deluxe board for both parts, I was able to answer that question.

At idle there's hardly any difference between SNB-E and IVB-E. Under load it looks like IVB-E is good for around a 20W reduction in total system power. It's not an insignificant savings, but definitely not enough to warrant an upgrade if you're on SNB-E already. Anyone looking to migrate to LGA-2011 for the first time will want to go with IVB-E as it is the more thermally efficient solution.

Power Consumption - Idle

Power Consumption - x264 HD 5.0.1 Average Load

Gaming Performance Final Words


View All Comments

  • randfee - Tuesday, September 03, 2013 - link

    anyways, I am likely to wait for Haswell XEONs next year, with AVX2 (which greatly enhances such scientific calculations if used) and DDR4 ;) Reply
  • noeldillabough - Thursday, September 05, 2013 - link

    dual Xeons, I have a supermicro 2U unit with low voltage xeons (they were $650ish each) and they're great. You can pick and choose board to have as much ECC memory as you want! Reply
  • wallysb01 - Tuesday, September 03, 2013 - link

    The E5-1660 will be the same as the 4960X, just not unlocked and with ECC. Same 6 cores, same 3.6-4.0 GHz range. Is the overclocking really worth all the hassle for maybe 20% speed increase, even if you had ECC?

    But I generally agree, it looks like Ivy Bridge 49xx/E5-16xx v2 is probably worth skipping. The upgrade over Sandy is not that much, and Haswell will likely bring 8-cores to the 59xx/16xx v3 space. Ivy Bridge for the top end only really made big gains in the 26xx space thanks to adding 10 and 12 core options, but man do you pay for them....
  • mapesdhs - Wednesday, September 04, 2013 - link

    You sound like the kind of person who'd benefit from a used SGI UV 10 or UV 100.
    No idea about their availability though.

  • mapesdhs - Wednesday, September 04, 2013 - link

    Oops, I was replying to randfee btw. Apologies for any confusion.

  • FwFred - Wednesday, September 04, 2013 - link

    Intel offers plenty of parts for you. See the Xeon line--it doesn't need to be high end. Reply
  • JlHADJOE - Tuesday, September 03, 2013 - link

    Intel Marketing: Honest guys. Reply
  • Michael REMY - Wednesday, September 04, 2013 - link

    VERY VERY congratulation to Anandtech for having put in the test the old flagships cpu ! Now we can really compare and read more & more deeper the evolution and interest in this architecture.

    It is great that someone underdstood people do not buy or change each year their whole computer, but only every 3-4 year .

    Very Thank you my Lord Anandtech
  • Remarius - Wednesday, September 04, 2013 - link

    Would be fascinated to see some statistics re tri and quad sli usage as I'm already using 3 titans. There seems to be almost no coverage at that end of the scale despite being one of the target markets for this chip. Reply
  • noeldillabough - Thursday, September 05, 2013 - link

    Heh I'd be happy with ONE Titan :) But I'd love to see those results too! Reply

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