New MBP i5 vs i7 temperature differences?

Discussion in 'MacBook Pro' started by olletsocmit, Jul 22, 2010.

  1. olletsocmit macrumors 6502


    Jun 24, 2010
    I just got a new MacBook Pro a month ago. It is the i5 2.4GHz 15inch. I run a lot of high memory intensive software and my Mac is hot a lot of the time. I rip like 6 DVD's a week. My mac is usually at like 78 while ripping and hot when it switches over to the Nvidia video card and running a few apps.

    I am just wondering if i would have bought the i7 instead... would it have run even hotter then my i5 does? Right now, im at 46C... if i had an i7 right now, would it be hotter than 46C right now?

    I bought the i5 and plan on upgrading to 8gigs of ram soon. I did this b/c i wanted to be able to actually use it on my lap w/o it being super hott. will the i7 run at the same temp as mine? should i have got the i7 and not the i5.

    Is it worth going from 4 to 8 gigs of ram? I just feel like my i5 with 8gigs of ram will basically be even to a stock i7. and if so... paying $400 for the ram upgrade would have been the same $ as buying the i7 and leaving the ram alone.

    Is 2.4GHz i5 (8gig ram) = i7 with 4gigs ram??
  2. Protokoll macrumors member

    Nov 3, 2008
    Honestly, you should buy a SSD. In terms of raw performance gain, that's the best cost-to-performance upgrade you can perform at this point. Unless you are running multiple virtual machines or video editing software that can comfortably use 8 GB of RAM, you will barely see any performance improvement. Definitely look into an Intel G2 SSD -- you will be glad you did. The base 15" i5 with an SSD will feel snappier than the top of the line 15" with an i7 and 8 GB of RAM.
  3. olletsocmit thread starter macrumors 6502


    Jun 24, 2010
    wow, that's sweet. They are still so damn expensive still. I need at least 120 to 150 gig hdd. People that are upgrading to them are getting like 40gig drives b/c there cheap. I need more space. I don't wanta have to move files around all the time and delete stuff after i use just to be able to live on a 40gig drive.
  4. Pax macrumors 6502a

    Dec 12, 2003
    Both i5 and i7 have the same Thermal Design Power of 35 Watts. So the i7 is likely to be similarly hot. Of course the i7 might be working slightly less hard for the same workload so might be slightly cooler. But I doubt it will be much.

    Macs tend to run hot. 46 C when idle, 78 C while working hard is very typical. You might see even higher temperatures, perhaps > 90 C if you really tax the CPU. For example if you rip from the HDD rather than from a DVD, the CPU won't need to wait so much for the DVD and you might see it work even harder & hotter.

    I don't think anyone really knows what these high temps might do to your Mac. Intel says the CPU is fine up to 105 C but we don't whether it affects its life or not. IMHO not to worry, Apple has made millions (tens of millions?) Intel laptops, they all get as hot as yours, so Apple/Intel probably know what they are doing. Certainly my C2D gets that hot or hotter (44 C now at idle, ~ 95 C with the CPU maxed out), I refuse to worry about it.
  5. demonsavatar macrumors regular

    Jun 26, 2010
    Yes the TDP is the same, however they often just create bins and mark similar levels of processors with the same TDP. For example the 2.4Ghz i5 and the 2.53Ghz i5 are literally made on the same piece of silicon. The one they marked as 2.53Ghz just passed the stability test with a slightly higher frequency. Even though they have the same TDP, the 2.53Ghz will run hotter because it is really the same chip just running at a higher frequency (and consequently using more power).

    The i7 is made on a slightly different piece of silicon, but there is no way it will run cooler because it has MORE transistors and is running at a HIGHER frequency. The "it's working less hard so it will run cooler" argument is not valid. The architecture of these CPUs is the same, if it is performing at the same level it is using the same amount of power and generating a similar level of heat. If anything it will run hotter at the same frequency because it has 1MB more cache, which means more transistors being used while it is doing calculations. It may finish those calculations quicker, but will run hotter during that time.

    HOW much hotter will the i7 run though? I doubt more than 5-7C hotter, if that. Someone with an i7 will have to elaborate. Thing is a 5-7C difference can easily be squashed with a better thermal paste or a small shift in the heatsink. I'm sure my MBP doesn't run at the exact same temperature at load as another one with the exact same specs, just because the thermal paste may have spread a bit differently.

    It is never that simple. IF the programs you are using are running out of ram at 4GB, then an upgrade to 8GB ram will speed you up WAY WAY WAY more than an upgrade to the i7 would have. IF the programs you are using are NOT running out of ram, you will get a MAX of 10-15% speedup with the i7 IF your programs are CPU-Bound. Note that you would have paid at least ~18% more for a 10-15% speed increase SOME of the time.

    SUMMARY for OP:
    Check if your programs are running out of ram. If they are, definitely get a RAM upgrade. If not, you won't see much of a change from getting any more ram.

    As for upgrading to i7, if you feel the ~18% higher price tag is worth the 10-15% speedup SOME of the time then go for it. By 10-15% SOME of the time I mean only when your CPU is pegged at 100%. If your CPU is not at 100% usage with your software, don't bother with wondering if the i7 was worth it, it probably wasn't.

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