Power Consumption

If you'll remember back to last year's Nehalem coverage I made a point to mention that the Nehalem architecture, thanks to its PCU and power gate transistors, was the most power efficient of the high end options. The lower the TDP, the more important power efficiency is and thus it's no surprise to see Lynnfield truly impress when it comes to power consumption:

Idle Power Consumption

At idle the Core i5 and Core i7 870 use less power than any other processor we've ever tested. Note that these idle power figures include an idling GeForce GTX 280. With a lower power graphics card, you could easily get to idle power consumption around 60W. Once we start seeing on-package GPUs, total system power consumption should drop even further.

Load Power Consumption - x264 HD Bench Pass 2

Under load the Core i5 and Core i7 870 continue to impress. They both draw less power than a Q6600 or a Q9650, all the while outperforming the two. Power consumption is also noticeably lower than Bloomfield.

These things are fast and smart with power. Just wait until Nehalem goes below 65W...

Gaming Performance Overclocking: Great When Overvolted, Otherwise...
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  • tajmahal - Tuesday, September 8, 2009 - link

    You fail to mention that Microcenter prices are for IN STORE PURCHASE ONLY. If you live about 6 driving hours away from a Microcenter like i do, then you're screwed.
  • Chlorus - Tuesday, September 8, 2009 - link

    Shhh! Don't spoil his self-righteous post with your troublesome facts!
  • strikeback03 - Tuesday, September 8, 2009 - link

    Does Microcenter have a limit on how many processors people can buy? If not, why isn't anyone buying these things and reselling them for less than the ~$280 that Newegg (and every other online retailer) do?
  • Solema - Tuesday, September 8, 2009 - link

    Anand,
    I know those prices you quoted are per-unit prices from Intel, but they are much more expensive than actual CPU costs. Given that I can get the following from Micro Center, and that I plan to overclock and run two 8800GTS 512's in SLI, what would you recommend?

    i5 750 - $179
    i7 920 - $199
    i7 860 - $229

    It still seems to me that the additional overclocking flexibility of the 920 (especially on stock voltage), coupled with the better multi-GPU performance would make that the best CPU to purchase, no? Given that P55 motherboards currently only retail for about $50 cheaper than many x58 boards, wouldn't the extra $70 cost for x58+i7 920 over a P55+i5 750 be worth it? You get better multi-GPU performance, better overclocking, better RAM performance, and future upgradeability to 6-core CPU's. What am I missing that would tip the scales in favor of the i5?
  • Pneumothorax - Tuesday, September 8, 2009 - link

    the 920 for sure as you get a HT CPU for even cheaper than the 860. Both should overclock the same.
  • dman - Tuesday, September 8, 2009 - link

    So, do they support Hardware Virtualization? And don't give slack about not targeted at that market, specifically, does this support Windows 7 virtualization mode?

    I searched and didn't see it covered. I've read that the i5 and lower do not support vt-d, but, I'm not sure how that translates to Windows 7 "XP mode" support... I do need to review a bit more, would be nice if this was covered in the review.

    I do know that this IS something that the Phenom family does support.

    http://www.virtualization.info/2009/07/intel-core-...">http://www.virtualization.info/2009/07/...core-i3-...

  • ash9 - Tuesday, September 8, 2009 - link

    No Virtalization!! That maybe huge for corporate setups,

    how did I miss that.

    It should have been reported
  • has407 - Wednesday, September 9, 2009 - link

    VT-x != VT-d. You want, and may need, VT-x. Most people don't need VT-d, much less know what to do with it or have a system that can make use of it--if you do, you're very unlikely to be using one of these CPUs.

    VT-x is Intel's name for processor virtualization features; it is part of the processor. All Core iX CPUs support it. VT-x is required for some hypervisors, (e.g., MSFT HYperV), but not all, although most (all?) require it for running 64-bit guests.

    VT-d is Intels name for for IO virtualization (specifically "directed IO"); it is, or has been, part of the northbridge. For VT-d to be useful, you need a chipset that supports it; a MB/BIOS that supports it; and a hypervisor that knows how to use it. VT-d is primarily of interest to VM's that want to dedicate direct access to hardware by guests, and avoid the overhead of the hypervisor for that IO.

    When you see "CPU X supports vT-d", it means the chipset for CPU X supports VT-d (the P55 supports VT-d). Whether MB/BIOS vendors choose to support it is another matter. Moreover, support for VT-d isn't simply yes or no; support varies by chipset (e.g., the P55, like the rest, support virtualizating a subset of interfaces).

    In short:

    1. Based on Core iX chipset capabilities (e.g., P55, X58), VT-d support is an MB vendor decision--not a function of the CPU model.

    2. Which vendors support VT-d, and to what extent, is more often than not clear as mud, and the topic of much discussion in some threads.

    3. If VT-d is important to you, you're probably running a heavy virtualized workload on an MP system with 10Gbe or very fast DAS--certainly not a Core iX. (Only exception of interest to others might be for access to GPU's by VMs)

    What the new processors throw into the mix is an integrated PCIe controller, which also means an integrated DMA controller (at least I hope it does). Whether that supports VT-d is unknown (I haven't been able to find a definitive answer).
  • Gary Key - Tuesday, September 8, 2009 - link

    VT-d is enabled on the i7/870-860. It is not enabled on the i5/750, just VT-x is available on it. I am working on Windows 7 XP mode as we speak.
  • Jakall78 - Tuesday, September 8, 2009 - link

    Reading this site for years, but there is something wrong going on here. Besides some slideshow pictures from Intel and 2-3 tests... there is nothing. That is not the way reviews are done. Look at the SSD reviews, THAT is a review(both of them actually). Now please look at this review
    http://translate.google.com/translate?prev=hp&...">http://translate.google.com/translate?p...mp;sl=ro...
    and say it`s not better...
    * I`m not making any false advertising here, I just found a better review.

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