Would you pick 2.3GHz or 2.6GHz if both had same price for rMBP? (Speed vs Batt,Heat)

Discussion in 'MacBook Pro' started by Starfyre, Oct 25, 2013.


What processor would you pick for your rMBP if they all had the same price?

  1. 2.3 - Less powerful, 1 hour more of battery, cooler (but still warm/hot)

    39 vote(s)
  2. 2.6 - Most powerful, but shaves off up to 1 hour of battery under load, runs hotter

    64 vote(s)
  1. Starfyre, Oct 25, 2013
    Last edited: Oct 25, 2013

    Starfyre macrumors 68030


    Nov 7, 2010
    Power vs. Heat and Battery Life

    Based on limited reviews from LaptopMag of the 2.3GHz 15'' Macbook Pro, we can see with the 15'' w/2.3GHz processor, the 15-inch MacBook Pro lasted 8 hours and 57 minutes in the LAPTOP Battery Test.
    Though the 2.6GHz does provide more power... history has shown from the Macbook Air, an i5 to i7 upgrade (despite low clock speed difference) though at idle, may only have a 15 minutes difference in battery life, under heavy loads the battery life goes down close to an hour and the thermals of course become much hotter.

    Given this fact, the 2.6GHz under load most likely will shave off almost an hour of battery life leaving with maybe just 8 hours or less. Thermals would probably also increase up to the high 90s underside near the hinge and the bottom center area could go up to the low 90s.

    So if the 2.3GHz and 2.6GHz processor were equivalent in price and cost was not an issue, what processor would you pick?
  2. tmoney468 macrumors 6502a

    Mar 13, 2007
    Always pick the faster processor. You will be thankful 3 years down the road
  3. RobobVT macrumors member


    Oct 25, 2013
    I agree just got the 2.6 13" rMBP and I am satisfied with it. My logic was get the faster processor now and have it last longer, I did not need 16gig ram so I splurged on the faster processor and bigger SSD
  4. Starfyre thread starter macrumors 68030


    Nov 7, 2010
    It would be nice if the Verge or some other review came out with tests for the maxed out 2.6GHz one.
  5. wordoflife macrumors 604


    Jul 6, 2009
    I'd get the 2.6. Don't know what you do on your laptop, but I don't really do anything too demanding when I'm on battery.
  6. mslide macrumors 6502a

    Sep 17, 2007
    That's not a good reason at all to get the faster processor in this case. This is only a small, incremental speed boost. That extra speed is most noticeable when the machine is brand new and becomes less and less noticeable as the machine ages. Just compare any 3+ year old MBP today. They'll all feel the same... slow.

    If we were taking differences in the number of cores than I'd agree with you but this is only a very small speed increment. That's why I never pay extra for the faster processors.
  7. rpungello macrumors member

    Oct 4, 2011
    I did get the 2.6GHz, even though it cost $180.
    If they were the same price, the 2.6GHz would be a no brainer.
    Yes, it uses more power, but it should also get through computationally intensive tasks faster.
    That means it'll be drawing more power for less time, so the battery drop for, say, converting a video probably wouldn't be that different.

    Plus, as others have said, I don't really do anything CPU intensive while on battery. If I do, it's not for long.
  8. Atomic Walrus macrumors 6502a

    Sep 24, 2012
    I disagree, really. When you see what a CPU 3 years from now is doing, the 7-8% performance gain you picked up won't have any impact on how old and outdated the machine feels.

    Just for fun, if we start with today's mid level option (2.3) and add 40% to it we get (using those Geekbench numbers for single core speed again):

    3100 * 1.4 = 4340

    When the "mid range" option for a CPU is getting 4340 and the top end is getting (using the current year's 7.76% speed variance between mid and top options) 4676, will it really make a difference if your CPU is scoring 3100 or 3330? That's 66.3% or 71.2% of the hypothetical 2017 MBP's (top CPU option) performance. Either way you're basically 30% slower than the current generation.

    Buy the upgrade if you want the power now, not because of some idea about future-proofing. I can assure you the CPU upgrade I got on my 2010 17" MBP doesn't make its Arrandale CPU seem any less outdated, even if we only consider single core performance (it was the last dual core used in large MBPs).
  9. cirus macrumors 6502a

    Mar 15, 2011
    I guess I'd pick the cooler option.

    However, is there not a 'power saver mode' in OSX which limits the CPU to 1.2ghz/800mhz like in windows? With power saver battery life will be pretty much the same.

    Almost no one actually needs the speed.
  10. johnnylarue macrumors 6502a

    Aug 20, 2013
    Sounds like we have/had the same MBP 17.

    And I couldn't agree more. Even given a modest 10% performance gain with every yearly MBP refresh, those 0.3GHz are a drop in the ocean compared to generational updates.

    That said, I will likely still buy the 2.6GHz machine to satisfy some emotional/psychological need I have to feel like I own the very best, but I will do so knowing that it won't make an ounce of difference in terms of future-proofing or resale value. It's pure luxury, and the people who will notice it the most (or at all, for that matter) will be hardcore industry pros/power-users who should probably be using desktops anyway.
  11. neteng101 macrumors 65816

    Jan 7, 2009
    Power > battery life.

    If you wanted battery life, and its your primary concern, go with the MBA.
  12. Atomic Walrus macrumors 6502a

    Sep 24, 2012
    I put an SSD in the 17", which definitely helped, but it still gets beaten by this year's i5 Air in CPU benchmarks. Considered trying to sell it, but doubt I'd get more than like $600 for it at this point considering any market for 17" MBPs that exists will be looking for 2011's quad core.

    I definitely know what you mean as far as the upgrade. To be honest if I had already been BTOing I might not have been able to resist it, but in the end I picked up the in-store model since it had everything else I wanted (16/512). I've already got my sights set on Broadwell so I don't think I'll have any regrets in a 1 year span (assuming I can manage to avoid putting any scratches or dents on the thing).

    Just noticed the thread title said "for the same price." For an identical price I'd go with the 2.6, since I am not physically capable of resisting free performance upgrades (like the 750m). If you told me I could get a 4770K (desktop chip) that would cause the machine to literally melt I'd probably still take it if it were free.
  13. johnnylarue macrumors 6502a

    Aug 20, 2013
    Ha! Same. GIMME MOAR POWER!!!

    I figured I should qualify my vote (for POWER!!) with the disclaimer that 0.3GHz is, all told, a relatively puny power boost. But if someone told me I could get it without dropping the $180 I'm about to spend, I'd be all for it. ;)

    And yes, I also had a (512GB) SSD in my MBP17. Overall, the machine was still running great when it was stolen in August. I probably wouldn't have been looking at the Haswells otherwise, to be honest.

    And to go even further off topic, I will say that Broadwell CPUs are looking promising from this vantage point, but remember that we're seeing it through "Next-Gen-coloured glasses". There was equal hype for Haswell, as there was for Ivy Bridge, but the real world performance boosts usually get boiled down to about 10-15% when all is said and done.

    Sandy Bridge was probably the last truly significant leap in performance, with laptops going quad-core for the first time. If Broadwell brings IGZO, a truly game-changing iGPU from Intel, as well as the promised 30% gain in efficiency under high CPU loads, it has the potential to be just as significant... but no guarantees that will come to pass.

    And I know this is pure conjecture, but the fact that Apple chose to "hold out" on bumping the cameras to 1080p suggests that they might be saving it to sweeten the deal for an even less impressive future refresh... Maybe a traditional February/March speed bump? Or maybe, just maybe, Broadwell will just be another boring, predictable 10-15% performance boost. Time will tell.
  14. jerrykur macrumors newbie

    Oct 25, 2013
    I go with the lower clock rate. The performance difference is minimal and running slower means running cooler. That translates to longer battery and component life, and most importantly for me, the fan run less often. I can't stand to hear fan noise from a computer.
  15. Starfyre thread starter macrumors 68030


    Nov 7, 2010
    I find it funny how reviews seem to say the fan noise can get really bad, even though the rMBPs are supposed to have quieter fans.
  16. rick3000 macrumors 6502a


    May 6, 2008
    West Coast
    Taking a different tact than the heat/battery life issue, (because face it any computer under heavy use is going to have decreased battery life and generate significant heat), this is my reasoning:

    In the past, I would have gone for the 2.6Ghz, but I will be buying a 2.3Ghz because BTO can be a nightmare if the computer ever breaks. I had it happen to me my first week of college. My BTO MBP broke, and the replacement was going to leave me without a computer for a week while they ordered a new one.

    Instead I took a refund and the non-BTO high end MBP the same day. If you depend on your computer everyday, and cannot go a week without it, I would not buy a BTO machine ever again. Most Apple Stores do not stock BTO variants, especially after a year or more.
  17. M5RahuL macrumors 68030


    Aug 1, 2009
    In order of priority ( for me. )

    1. RAM
    2. Storage
    3. Processor

    For the average user, those 300 MHz will make zero difference !

    But, if the price is same....
  18. Starfyre thread starter macrumors 68030


    Nov 7, 2010
    They all of 47 TDP too... Sounds like more fan noise is inevitable compared to 2012 models :(
  19. Quu macrumors 68030


    Apr 2, 2007
    Considering that the 2.3GHz and 2.6GHz chips both have the same TDP which is based on the maximum possible load each chip could ever be under I don't see why choosing the 2.6GHz would somehow reduce battery life by an hour compared to the 2.3Ghz chip.

    I've been in the computer industry for over a decade now and the way that Intel maintains power consumption while increasing performance within the same series like these 2.0 2.3 and 2.6GHz chips all at 47 Watts whilst based on the same architecture is by reducing voltage as the speeds increase.

    Basically they "bin" the chips based on how stable they are at different voltages. The chips that will run at 2.6GHz with extremely low voltage (lower than the 2.0 and 2.3GHz chips) become the highest end 4960HQ 2.6GHz chips. This is also why the prices are so high because the volume of chips capable of these clock speeds at these low voltage ranges are in short supply.

    So which chip should you be buying? The fastest one, if your wallet permits.
  20. garrettheaver macrumors newbie

    Oct 27, 2013
    That's not quite how I understand TDP. Is it not that TDP is that maximum a cooling system will be required to dissipate under normal usage? Actual power usage may end up being lower or higher than that. Intel lump their processors together in TDP categories so it's conceivable that under normal usage the i5 could actually consume a lower amount of energy (not having to hold such a high base frequency voltage) than the i7 thus resulting in better battery life on the i5?

    I don't have any hard knowledge to back this up with, just speculation but I'd be delighted if someone could give conclusive knowledge and evidence.
  21. Quu macrumors 68030


    Apr 2, 2007
    The TDP does stand for Thermal Design Power but they express it in watts, which is a unit of power.

    Intel uses the absolute best chips for the highest clock rates while still maintaining the same TDP. This makes the 2.6GHz processor the most energy efficient and that chip would actually use less power than the 2.0 and 2.3GHz chips when run at the same speed as those chips (2.0 vs 2.0, 2.3 vs 2.3) at 2.6GHz it will use the same exact amount of power as the 2.0 and 2.3 chips when they are also running at their rated clock speed.

    This is the whole reason for the TDP labeling so that you know exactly the maximum power draw and thermal envelope of the CPU.

    You would expect the thermal heat output and energy in use to differ but it actually doesn't because these chips are all identical right down to the position of their silicon the only difference physically is that some chips have stronger bonds or slightly more efficient transistors (maybe due to less stress during their creation) and thus can handle higher frequencies at the same voltage levels of their sibling chips.

    Another way to examine this is by comparing the Intel 130 Watt TDP 2011 socket processors. They come in both 4 and 6 core versions but pull exactly the same power from the wall socket when the chips are at 100% maxed out load and obviously the 6 core chips are obviously quite a bit faster.
  22. garrettheaver macrumors newbie

    Oct 27, 2013
    Cool. So how does this fair out when you also consider the GPU into the equation? The TDP must take that into consideration also I assume and it's current workload vs CPU workload?

    Also (sorry about the slight off-topic digression here), how does this fair out when comparing different models such as the i5 and the i7? I'm debating the 13" options myself and if there is a significant difference in battery life then the extra 7-11% performance probably isn't worth it to me.
  23. Quu macrumors 68030


    Apr 2, 2007
    The GPU definetly factors, the 2.6GHz chip actually has a faster Iris Pro than the other chips, it goes to 1.2GHz instead of 1.1GHz on the 2.3GHz chip.

    I imagine the power consumption is something like this when the entire chip is utilised both Graphics and CPU.


    I imagine if you use the 750m that the CPU will stay longer at its maximum clock rate due to Iris Pro not being utilised that is until you start gaming on the 750m then the total TDP of the entire laptop will mean the CPU will probably throttle somewhat to compensate.

    When comparing CPU's TDP you can only really compare within the same architecture. So Haswell vs Haswell. i5's and i7's both use the Haswell architecture so it's fine to compare their TDP's.
  24. johnnylarue macrumors 6502a

    Aug 20, 2013
    Quu, walk me through this one. The way I'm interpreting your graph, it implies that the 2.6GHz chip would be consuming the same amount of power when it's operating at 1.8GHz as the 2.0GHz chip at 1.5GHz, implying that the faster CPU is actually is able to run faster while consuming the same amount of power as the lesser powered chips... which doesn't make sense to me.
  25. Quu macrumors 68030


    Apr 2, 2007
    Yes this is correct. You need to understand how chips are fabricated and categorised by Intel.

    They make a wafer which is a large disc that contains many many processor dies. The die is the part of the processor that houses all the transistors for the chip, all the cores and so forth.

    Not all dies that come from these wafers are born equal. Subtle variations during the manufacturing process can result in some dies which simply outperform other dies when benchmarked by Intel in PPW (Performance Per Watt).

    What this means is they test each die they make and some will run at higher speeds than others when presented with the same voltage level. This also means faster chips can run at slower speeds with less voltage than others.

    Intel then categorises these processors as different model numbers, it is called speed binning. Not a lot of people know this but the Core i5 and i7 processor in the MacBook Air and 13" MacBook Pro which are Dual Core processors are not actually Dual Core they are Quad Core dies which simply don't perform adequately enough to be sold as Quad Core parts.

    This could be for a number of reasons such as 2 cores not performing under low voltage tolerances or two cores not working at all or it could be a single core that is physically damaged. Whatever the case they "bin" those dies down and sell them as Dual Core parts.

    The same thing happens even when all the cores do work fine thus we have the same processor with the same TDP of 47 Watts in three different speed offerings, 2.0GHz, 2.3GHz and 2.6GHz

    You need to look at their power consumption as a gradient from their idle speedstep state of 1GHz to their highest performance state (2.0, 2.3 and 2.6) they all have the same total TDP of 47 Watts, the TDP is calculated by the processor being at maximum load under a normal working scenario, this means application load indicative of user behavior not a program that loads every transistor in the processor like an Intel CPU Burn test.

    This means that the 2.6GHz Processor is the most efficient in PPW (Performance Per Watt) because in the same power envelope as the other two processors it is able to deliver 300MHz more performance.

    I hope this was helpful.

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