The MacBook Pro Review (13 & 15-inch): 2011 Brings Sandy Bridge
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on March 10, 2011 4:17 PM EST- Posted in
- Laptops
- Mac
- Apple
- Intel
- MacBook Pro
- Sandy Bridge
Thunderbolt
We wrote about Thunderbolt when the new MBPs launched, and about the differences between when it existed as Intel's codename Light Peak like we used to know it and saw at IDF. Thunderbolt differs technically and in practice in a number of ways. The short version of the story is that Thunderbolt is Light Peak sans light in this initial form (electrical right now), uses the mini DisplayPort connector on the MBP, and is capable of two channels of full duplex 10 Gbps traffic, for a theoretical 20 Gbps up and down. Thunderbolt requires a controller on the host and peripheral, uses 4 PCIe lanes, and connects to Display Port internally on the MBP's discrete GPU. One of the interesting things is where those 4 lanes come from on the 2011 MacBook Pro.
Thunderbolt can supply 10 watts of power and support up to 7 devices, up to two of which can be DisplayPort 1.1a devices. Just PCIe and DisplayPort are tunneled over Thunderbolt links. However, you can connect a standard DisplayPort monitor to the jack on the MBP and use it natively as well.
Sandy Bridge brings 16 lanes of PCIe really purposed for running a GPU. Interestingly enough, the discrete GPU on the 2011 MBPs uses just 8 PCIe lanes:
So where do the remaining 8 lanes get used for? They're split into 2 x 4x ports, one of which is for Thunderbolt. It's surprising, but this configuration is totally supported. Originally I speculated that the other 4x lane was being used for another PCIe interface device in the MBP (the SDXC card reader and BCM7765 are both 1xPCIe devices), but it appears they're unused.
Intel's Thunderbolt controller
Thunderbolt launches with Apple, but isn't Apple exclusive. Intel reports that we just likely won't see adoption in the PC space until 2012. In addition, there's no per-port licensing fee or royalty for peripheral manufactuers wanting to use the port or controller, which are entirely Intel's. The controller is actually of appreciable size on the 2011 MBP:
Initially, Thunderbolt is electrical only, though the optical version of Thunderbolt is coming later this year. Optical cabling will be compatible with this electrical version through the use of electro-optical transceivers on the cable ends.
Bottom: 2011 MBP with Thunderbolt port, Top: 2010 MBP
We can't test and see whether Thunderbolt works or does anything right now, because there aren't any devices on the market with support. That said, Western Digital, LaCie, Promise, and other external storage manufacturers have stated that drives will arrive shortly, which we will surely take a look at. There are also rumors of various high end DSLRs shipping with Thunderbolt in the near future, though that's anyone's guess.
There's a field for Thunderbolt in system profiler, but even with a DisplayPort monitor attached, it shows nothing connected:
Interestingly enough, in Windows there's no trace of Thunderbolt at all. There aren't any unknown devices in the device manager, no device ID either. Hopefully Boot Camp drivers come along for Thunderbolt in Windows before devices start rolling out.
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zhill - Friday, March 11, 2011 - link
Hmm... so I mostly disagree, but the fact that there is some confusion is problematic as well.I assumed (the need to assume is the problematic part) that the main battery life tests (Web loads, etc) were run with OSX doing whatever it wants. The point of the gfxCardStatus tests was to specifically point out the difference in power consumption with each card being used. The only way to expose that behavior explicitly is to manually enable/disable the dGPU.
So, I think the methodology makes sense, but I agree that Anand should make it clear in the general battery-life section that OSX is managing the GPU in stock form with no gfxCardStatus inferference.
7Enigma - Friday, March 11, 2011 - link
I ran the numbers. The values (in minutes) that were reported in the 1st and 3rd charts of page 15 which correspond to the light and Flash-based web surfing are dead on the bottom of page 9 numbers where the discrete GPU has been TURNED OFF.It is so bad that after running the numbers if you were to use the data from page 9 the 15" MacBook Pro would be so far in last place on the Flash-based chart (at 177minutes) that the next highest is over an hour and a half LONGER.
zhill - Friday, March 11, 2011 - link
I believe he's using Safari in the web and flash web tests, and mentions:"Another contributing factor is the new 32nm iGPU which is active full-time under Safari. " When discussing the Flash problem (on pg 9) he specifically mentions Chrome + Flash activating the dGPU.
So, the question is: what is the dGPU behavior for other browsers? Do Firefox and Safari only use the iGPU or is the dGPU activation only in Chrome? It needs to be addressed in the article more fully for no other reason than clarity and so users will know that choice of browser may impact battery life very significantly.
7Enigma - Friday, March 11, 2011 - link
That is a good point (missed the Chrome/Safari switch), but it is also puzzling that the numbers from both charts match up perfectly. I would have expected a bit of difference between Chrome and Safari even if the dGPU issue is taken away just due to coding differences, but if you divide the minutes by 60 from the earlier page you'll get the EXACT same number of hours posted in the later battery numbers. The only way to describe this without it being the same number would be if they are comparing numbers from 2 different browsers in the same chart without labeling as such which I find very hard to believe.7Enigma - Saturday, March 12, 2011 - link
Seriously not a single reply from one of the authors?IlllI - Friday, March 11, 2011 - link
theres hardly much difference between the 13in model and the 17in. so basically you are paying $1000 more for 4 inches.alent1234 - Friday, March 11, 2011 - link
i5 to i7, discrete GPU, more hard drive spacealmost same price difference if you went with dell/hp
khimera2000 - Friday, March 11, 2011 - link
Just so you know looking at the recommended configuration of hp envy cost 1932, a maxed out 3D vision dell xps 17 cost about 2480 but has a sell that brings it down to 2244 (dual HDD no SDD) where as the base configuration of the mac cost 2500. so..,. no even if you throw in the discreet, I7 increased harddrive space your still over the mark when you compare to windows notebooks.How did i find these numbers? opened up the web sight for each respective company and looked at what they had as of 5:00 PM 3/11/2011 applicable to US customers (after all they where the US versions of the sight) except for dell no others where offering an automatic discounts.
jed22281 - Friday, March 11, 2011 - link
Should've done the 13" and then jumped up to the 17".Is there some reason you're not interested in the 17" versus the 15"?
Thanks!
jed22281 - Saturday, March 12, 2011 - link
Anand, Brian, or Vivek?Thanks!