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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Anand Lal Shimpi - Friday, March 11, 2011 - link
Thank you for reading them, comments like this really do make it all worthwhile :)You wouldn't believe how much time was spent making sure Apple wasn't doing something funny with the max turbo frequencies. At the end of the day it was a non-issue, but we had to be sure.
Take care,
Anand
Ryan Smith - Friday, March 11, 2011 - link
Just to add some technical background to this, it's actually quite complex to get a CPU speed reading on modern CPUs. Mac OS X's Sysctl reports the base speed of the processor, regardless whether Turbo Mode is active or not. So on the 15" low-end QC model you will always see 2.3GHz.To actually read the instantaneous speed of any given core, you need to peek at the CPU itself and count the cycles - Intel actually has a handy document detailing an algorithm to do this(1). The issue with that is that it requires peeking at the Model-Specific Registers (MSRs), which require Ring 0 access; or in other words you need a broker at the driver level to do it.
Linux already does this (/proc/cpu/0/msr), and on Windows it's fairly trivial to load a driver alongside an Admin-level application to do this(CPU-Z, etc). Under Mac OS X this requires installing an Extension (at least as far as I know) which gets messy. If you don't go through this process you'll never be able to read the core speeds accurately, which is why there's virtually no Mac software capable of this.
Fortunately MSR Tools exists, and it has a 32bit extension to allow it to peek at the MSRs. The right answer of course is always the last answer you try, so this was only after trying several other ways of calculating the CPU speed and a couple different OS-agnostic benchmarks to try to rule out OS differences.
1) http://download.intel.com/design/processor/applnot...
tno - Friday, March 11, 2011 - link
+1I've been planning to plunge into Mac ownership for sometime, especially with grad school looming I really want something that's more comfortable to work on than my netbook but still fairly portable. This review really helped me gauge whether it was worth putting in the extra cost for a 2011 13" MBP or settle for a discounted 2010.
So am I all set? Hardly! Now I need to see what the 2011 13" MBA has to offer! I'm praying that cost stays roughly the same and a move to a ULV SNB leads to 12+ hour battery life and a similarly huge leap in performance as the move lead to in the MBP. I am a sucker for lightweight form factors.
This article is also the first one to make me ever consider the 15" MBP. I have been fairly opposed to the bulk but the performance is quite something. If I went that route then I would probably have a C2Q, water-cooled, ATI and SSD driven rig to put up on AT forums. Taking offers!
tno - Wednesday, May 4, 2011 - link
Rezzing a dead thread! I bought the 13" MBP! $999 at MicroCenter, too good to pass up! So . . . who wants my rig?JasperJanssen - Saturday, August 6, 2011 - link
I, on the other hand, have gone the other way. My MBA13 is being put together in China now.ltcommanderdata - Thursday, March 10, 2011 - link
A great review. I do have some additional questions though. First, given Apple was the instigator of OpenCL, it'd be great if you could run some OpenCL benchmarks. Are the Sandy Bridge MacBook Pro's disproportionately faster than the Arrandale MacBook Pro to indicate that OS X has CPU OpenCL drivers that can take advantage of AVX? Probably not, and this will hopefully come with Lion. Given nVidia's GPGPU push can the HD 6490 still keep up with the 330M GT in OpenCL? How does the HD6750 do?http://www.bit-tech.net/hardware/graphics/2011/01/...
"'[Intel] will be releasing OpenCL graphics drivers to developers during the course of 2011. [Intel] continue to evaluate when and where OpenCL will intercept various products"
And is there secret Sandy Bridge IGP OpenCL support? Bit-tech got a quote from Intel that Sandy Bridge IGP OpenCL support was inbound sometime this year and if anyone would be motivated to get it done it'd be Apple.
And finally, does Apple now support hardware H.264 decoding on ATI or Intel GPUs? Previously, only a few nVidia GPUs were supported in Snow Leopard, such that the Arrandale MacBook Pro actually had to power up the 330M GT to decode H.264 wasting power compared to the perfectly fine Arrandale IGP if Apple just wrote the drivers. Do the new Sandy Bridge have the ATI GPUs doing H.264 decoding now, is the Intel IGP supported, or in the worst case is no H.264 hardware acceleration available now that nVidia GPUs are gone? Perhaps lack of hardware H.264 decoding is what makes the FaceTime HD CPU usage so high? QuickSync is only accelerating the encoding phase?
Anand Lal Shimpi - Friday, March 11, 2011 - link
Some answers:1a) I don't know of any good GPU based OpenCL tests under OS X at this point. I'm not even sure if Apple's Intel HD 3000 driver supports OpenCL.
1b) Intel mentioned SNB's GPU technically supports OpenCL however there are no plans to release a public driver at this point.
2) Hardware H.264 decoding is enabled on the 2011s and it is used while FaceTiming, at least according to Apple.
Take care,
Anand
ltcommanderdata - Friday, March 11, 2011 - link
Thanks for the reply.http://www.macupdate.com/app/mac/33632/smallluxgpu
In regards to OpenCL testing, most people in OS X seem to use SmallLuxGPU which is an OpenCL raytracing benchmark. I don't have much experience with it, but it might be worth a try.
In regards to hardware H.264 decode, do you know if the IGP is doing it or does the discrete GPU still have to be powered up as in the 2010 Arrandale MacBook Pros?
Thanks
Anand Lal Shimpi - Friday, March 11, 2011 - link
It's my understanding that the IGP can do the decoding, although note that while FaceTime is running the dGPU is enabled by default.Good call on SLG, I had forgotten about that :)
Take care,
Anand
secretmanofagent - Thursday, March 10, 2011 - link
Hello authors,On one of the pages, you mentioned this:
"This isn't Mac specific advice, but if you've got a modern Mac notebook I'd highly recommend upgrading to an SSD before you even consider the new MacBook Pro. I've said this countless times in the past but an SSD is the single best upgrade you can do to your computer."
Is there an article where you recommend the best update for my model? Should I even bother with the drive? I realize the X3100 is going to still hamper any sort of graphical performance, but wondering if it's worth the effort.
Out of curiosity as well, would a Time Machine restore be possible if you update the drive?