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
Good article. I was thinking about your issue with the high cpu utilization, and could it simply be a reporting issue? Could the cpu performance counters or OSX be reporting QuickSync as part of the cpu rather than the GPU? This would certainly be strange and not accurate, but given that intel seems to list QuickSync and HD3000 separately, maybe the reporting stats aren't accurate. Presumably this would be an issue in both Windows and OSX, but at the driver level there could be differences. Just a thought.Have you, or anyone else, noticed heat issues with the MBP lid closed versus open? Aren't the vent ports along the back next to the hinge such that when open they can vent, but when closed airflow could be inhibited?
Anand Lal Shimpi - Friday, March 11, 2011 - link
I thought about that too, but there seems to be a genuine increase in thermal output from the CPU - higher than I'd expect from idle cores and the quick sync engine active.I haven't personally noticed any heat issues with the lid open vs. closed, seems to behave similarly (although now that you mention it I feel like open I do get temperatures a couple of degrees cooler than when it's closed - that could just be psychological though as the comparison is completely unscientific).
Take care,
Anand
Omid.M - Friday, March 11, 2011 - link
Anand,So do the 15-17" MBPs have hardware acceleration support for Flash? I didn't see that explicitly in the review; sorry if I missed it, but I tweeted you asking for this.
The last MBP update, Anand said the 13" he could highly recommend, but the 15" got way too hot under load.
This update, Anand said the 13" he could highly recommend, but the 15" gets way too hot under load.
Hmm. (not insinuating anything, Anand and crew)
I find that odd. But, maybe it's a good thing: I'm not comfortable buying an MBP until Apple build TRIM support for 3rd party SSDs into OSX. I would not want the Apple SSDs.
My early 2008 MBP is still running fine, although I'm tempted by the QC models. Maybe waiting until Ivy Bridge, in hopes of a cooler laptop, will be enough time to see if Apple brings TRIM for after-market SSDs.
I'm disappointed, but I guess this review saved me some money until next year.
Anand Lal Shimpi - Friday, March 11, 2011 - link
Sorry I think I missed your tweet! I measured around 40 - 60% CPU utilization of a single core when viewing a 1080p HD video in YouTube on the new 15-inch MBP (same CPU usage for both the iGPU and dGPU).The frame rate was perfectly smooth, but it's unclear to me how much lifting is being done by the GPU here.
Last year's 15 was pretty warm, but this year's model definitely didn't take a step back in that department - transistor count nearly doubled after all!
The move to 22nm should bring about marginal updates to architecture so I'm hoping for lower power consumption at similar performance levels.
Take care,
Anand
Omid.M - Friday, March 11, 2011 - link
Anand,You mentioned in the last MBP refresh/review that the 13" showed support for TRIM in OSX (evidenced in System Profiler, I believe).
You also said in this refresh/review that Apple supports TRIM for its own SSDs only.
To my knowledge, the last MBP generation had the SSD option for both 13" and 15-17" models, meaning the same SSD was offered across all models.
If TRIM is only supported for Apple SSDs, why did we see an evidence of TRIM in last year's 13" model but no evidence for the 15/17, assuming the same SSD was offered across the entire line and assuming the version of OSX shipped with the last models was the same across the line?
Was that due to different chipset drivers because the 13" had the Core 2 Duo/Nvidia combo, and the older 15/17 had Core i5/i7 (thus, newer chipset) ?
Does it make sense what I'm asking?
tno - Friday, March 11, 2011 - link
Apple ships different versions (small tweaks) of OSX with different laptops, and there is the key. If you recall, the field in System Profiler was populated indicating that at some level the chipset (Nvidia sourced) supported the instruction, but SSDs that supported the instruction did not.So you're correct, Nvidia chipset driver supported TRIM, but the OS did not implement the instruction. The Core i5/i7 integrated chipset driver had no support for TRIM.
http://www.anandtech.com/show/3762/apples-13inch-m...
name99 - Friday, March 11, 2011 - link
"I saw a number of different MCS (modulation coding scheme) values with the 2011 MBP in the exact same place. Link rates from just below 300 Mbps all the way up to the expected 450. It seems to settle out at the expected 450 Mbps in the same room as the AP, it just takes a while, whereas other 2x2 stacks I've seen always lock onto 300 Mbps and stay there in the same room and position."Is the state of the art any better than this?
The reason I ask is that the simple WiFi problem (1x1 antenna, what is the best modulation + puncturing I should use for this SINR?) is well understood.
But once MIMO enters the picture there are so many more options available --- for example: should we try to use all receive antennas for different streams, and run those three streams at "robust" modulation, or should we transmit a single "fragile" (64-QAM, 5/6) stream, and rely on receive diversity to be able to detect it without error? If we send a "fragile" stream, should we use the transmit antennas to perform beam shaping to target more power at the target?
As I understand it, optimal methods for handling the juggling between all the different types of diversity available in the MIMO space still do not really exist (if anyone has a reference stating otherwise, please provide it).
If this is the case, it would not surprise if, on either the base station end, the laptop end, or both, you have a huge amount of bouncing around between different possibilities (of course with 3x3:3 the space is larger than with 2x2:2 or 2x3:2) because what is being used to make the choices are simply heuristics, not engineered algorithms, and the heuristics are extremely sensitive to the slightest changes in the SINR covariance matrix).
Brian Klug - Friday, March 11, 2011 - link
I haven't really played around enough with other 3x3 WiFi stacks enough to say for certain. I agree with you that a lot of this is it making some decisions based on whether to prioritize connection robustness or throughput rate. At close ranges, it certainly selects MCS that gives most throughput, but I'm still shocked to not see more 450 Mbps when in the exact same room as the AP.Moving away, you'll quickly fall back to single stream rates (but obviously still get MIMO range extension). You're exactly right that everyone has their own heuristics for how to do this based on SINR. I still haven't figured out how to actually grab SINR out on here, all I can see for the moment is just RSSI. Completely agreed though.
-Brian
MrCromulent - Friday, March 11, 2011 - link
Once again a very detailed, comprehensive and yet easy to understand article!I'd like to inquire once more about the C300: In the initial test, the C300 was criticized for poor garbage collection. Now it's considered an option for Apple notebooks. Has the GC been improved by Marvell in the last few firmware updates?
Griswold - Friday, March 11, 2011 - link
Interesting revenue information right at the start. Apple went from a computer- to a music&player- to a phone company. :P