6Gbps Performance

I installed the Intel SSD 510 in a 15-inch 2011 MacBook Pro as well as a 15-inch 2010 MacBook Pro to put together a 3Gbps vs. 6Gbps performance comparison. I turned to Xbench for some quick and dirty performance data:

SATA Performance—XBench 1.3
Intel SSD 510 250GB 3Gbps (2010 15-inch MBP) 6Gbps (2011 15-inch MBP) 6Gbps Advantage
4KB Sequential Write 157.8 MB/s 192.2 MB/s +21.8%
256KB Sequential Write 182.0 MB/s 257.1 MB/s +41.3%
4KB Sequential Read 32.5 MB/s 32.7 MB/s 0.0%
256KB Sequential Read 197.3 MB/s 315.6 MB/s +60.0%
4KB Random Write 47.8 MB/s 49.0 MB/s +2.5%
256KB Random Write 186.4 MB/s 260.9 MB/s +40.0%
4KB Random Read 14.5 MB/s 13.4 MB/s -7.6%
256KB Random Read 149.7 MB/s 207.3 MB/s +38.5%

As you'd expect, there's no real benefit to the new 6Gbps interface for random operations (particularly at low queue depths). Sequential speeds are much improved however. Xbench shows up to a 60% increase in performance in sequential operations.

You'll note that the absolute numbers are pretty low to begin with. A 128KB sequential read of the Intel SSD 510 on our desktop Sandy Bridge SSD testbed pulls nearly 400MB/s. On the new MacBook Pro we can't get more than 320MB/s.

Our sequential Iometer tests are run at a queue depth of 1 so there's no advantage there. The only explanation I can come up with (assuming Xbench's test is accurate) is that Apple may be aggressively implementing SATA controller power management under OS X. Capping the link's performance or aggressively putting it to sleep could reduce performance at the benefit of increasing battery life.

The other thing I noticed was that performance on the 13-inch MBP using Xbench was a bit lower than the 15-inch MBP. Take a look at these numbers:

SATA Performance—XBench 1.3
Intel SSD 510 250GB 13-inch 2011 MBP 15-inch 2011 MBP
4KB Sequential Write 155.3 MB/s 192.2 MB/s
256KB Sequential Write 184.8 MB/s 257.1 MB/s
4KB Sequential Read 30.4 MB/s 32.7 MB/s
256KB Sequential Read 201.8 MB/s 315.6 MB/s
4KB Random Write 49.6 MB/s 49.0 MB/s
256KB Random Write 183.9 MB/s 260.9 MB/s
4KB Random Read 13.9 MB/s 13.4 MB/s
256KB Random Read 144.9 MB/s 207.3 MB/s

I only noticed this with the Intel SSD 510, the Crucial RealSSD C300 and Vertex 3 both performed identically between the 13 and 15-inch MBPs. I'm not sure what's going on here at all, although I suspect that it's somehow related to the issues users have been having with some of these drives (more on this below).

SSD Recommendations

Where does all of this discussion about SSDs leave us? Unfortunately recommending an SSD for the new MacBook Pro today is pretty difficult but I'll try my best.

If you're the conservative type and just wants something that for sure works with little to no concern about absolute performance, the Apple SSDs are probably the safest bet. You'll get a drive that's much faster than a hard drive, fully supported by Apple and with TRIM support. Yes, that's right, OS X finally has TRIM support but Apple only enables it on it's own branded SSDs. To Apple's credit, given the number of problems I've seen with SSDs over the past couple of years it makes sense to lock down and only support drives you've validated. On the flip side however, Apple should be validating and working with controller makers to ensure all drives work under OS X. Making as much money as Apple does, I don't buy the "we didn't have the time/resources" argument.

If you are going down the Apple SSD path, at least the 128GB drive isn't super ridiculously priced, although I'm less comfortable recommending the 256GB version unless you can get it at $500.

Now if you want to get a faster SSD or actually take advantage of the 6Gbps interface, things get more complicated. I've heard reports of users having issues with the Intel SSD 510 and Crucial RealSSD C300. I've tested both drives as well as the OCZ Vertex 3 in three different MacBook Pros, and in all cases the drives worked perfectly. They were all detected as 6Gbps drives and all performed well. I should note that while I couldn't get the Vertex 3 Pro to work in the 2010 MacBook Pro, the Vertex 3 worked just fine in the 2011 MacBook Pro.

SATA Performance—XBench 1.3
13-inch 2011 MBP Crucial C300 256GB Intel SSD 510 250GB OCZ Vertex 3 240GB
4KB Sequential Write 239.0 MB/s 155.3 MB/s 319.9 MB/s
256KB Sequential Write 217.2 MB/s 184.8 MB/s 257.8 MB/s
4KB Sequential Read 35.1 MB/s 30.4 MB/s 33.3 MB/s
256KB Sequential Read 248.3 MB/s 201.8 MB/s 311.8 MB/s
4KB Random Write 175.0 MB/s 49.6 MB/s 247.8 MB/s
256KB Random Write 226.6 MB/s 183.9 MB/s 290.0 MB/s
4KB Random Read 19.1 MB/s 13.9 MB/s 21.1 MB/s
256KB Random Read 239.0 MB/s 144.9 MB/s 304.0 MB/s

SATA Performance—XBench 1.3
15-inch 2011 MBP Crucial C300 256GB Intel SSD 510 250GB OCZ Vertex 3 240GB
4KB Sequential Write 239.3 MB/s 192.2 MB/s 316.5 MB/s
256KB Sequential Write 218.8 MB/s 257.1 MB/s 282.0 MB/s
4KB Sequential Read 34.8 MB/s 32.7 MB/s 34.2 MB/s
256KB Sequential Read 245.1 MB/s 315.6 MB/s 306.7 MB/s
4KB Random Write 160.5 MB/s 49.0 MB/s 240.5 MB/s
256KB Random Write 227.5 MB/s 260.9 MB/s 311.3 MB/s
4KB Random Read 18.7 MB/s 13.4 MB/s 20.9 MB/s
256KB Random Read 238.2 MB/s 207.3 MB/s 303 MB/s

The Vertex 3 is the fastest drive out of the aforementioned three, but its availability and firmware maturity are both unknowns at this point. If you have to buy today and are ok with the chance that the drive may not work (given other experiences online, although I haven't seen problems), Intel's SSD 510 is likely a good runner up (at least for the 15-inch, the C300 seems to perform better on the 13).

As far as the reports of incompatibilities with these drives are concerned, I'm not really sure what's going on. I've been hammering on all of the drives, putting the system to sleep/waking it up, and haven't encountered any failures or high latency IO operations (stuttering) yet. That's not to say that these problems won't appear over time (I'm currently doing long term testing to figure that out now), but just that I haven't seen them yet.

If you are having issues with the Intel SSD 510, Crucial RealSSD C300 or anything else please email me (link at the top of the page) the following information:

1) What are the full specs of your MBP? Any upgrades?

2) Tell me about your SSD. Is it new out of box? Have you done anything to the drive? What model, firmware revision, etc...

3) Describe the symptoms of the issue—beachballs, data corruption, etc...? What do you have to do create the issue?

4) Is the drive detected as a 6Gbps drive or a 3Gbps drive?

5) Take me through your drive installation procedure, did you just pop it in, partition and install OS X?

6) Any visible damage to the SATA flex cable when you installed the drive?

7) Have you tried exchanging the SSD or MBP? Any difference in behavior?

We haven't seen any issues on three different 2011 models that we've been testing here extensively with the Intel SSD 510, Crucial RealSSD C300, OCZ Vertex 3 and OCZ Vertex 2. I realize a number of you are having issues so the more details I can get the better.

Apple's SSD Strategy The GPU Comparison


View All Comments

  • jb510 - Friday, March 11, 2011 - link

    It would seem to me their is one currently shipping Thunderbolt periphral... A 2011 MBP in target disk mode. Maybe you could drop an SSD in one and do some preliminary testing? Reply
  • jb510 - Friday, March 11, 2011 - link

    damn... wish i could edit that comment originally typed on my iphone... but their doesn't appear to be any way... (misspelling repeated for comedic effect) Reply
  • deadshort - Friday, March 11, 2011 - link

    Thanks for the genuinely informative review. Running both low-load and high-load battery tests is especially helpful to developers, etc.

    One question. You chose the 2.3Ghz/8MB cache system. Was that just 'cuz you swing that way, or do you expect significant performance benefits for some workload you care about? For these machines is it a 10% price goldplate, or a reasonable increment to keep these CPUs fed? I am seriously interested....
  • Brian Klug - Friday, March 11, 2011 - link

    I can speak for myself at least, but part of the reason for the 2.3/8 MB system choice was that it's the only preconfigured (Apple Store available) configuration that comes with the anti-glare display.

    Essentially, if you're a customer walking into the apple store and don't want the glossy/glare display, you're immediately forced into buying the highest-specced (and most expensive) MacBook Pro. It's frustrating because the only way to get lower specced systems is BTO online.

    Obviously we got these systems on launch date to immediately start working, and that was the reason for the 2.3 choice.

  • synaesthetic - Friday, March 11, 2011 - link

    You know, I don't get this thin crap. I really don't.

    I mean, I can understand it. From a purely aesthetic point of view. Sort of, anyway.

    I'm sick of "thin" gadgets with weak performance and fragile builds. Thick gadgets means more tech fits inside. My HTC Glacier is quite thin, and you know what? I wish it was thicker. It'd be easier to hold onto, and HTC could have put a bigger battery in it!

    Stop making things so stupidly thin. Instead of driving the miniaturization of components on "thin," why not take that same miniaturization power and make things a bit thicker... with more power/cooling/battery inside?

    Thin may be sexy, but powerful is even sexier!

    Then again, Apple's never really cared to broadcast the specs of their devices, hoping instead to gloss over it to such a degree that nobody questions paying ridiculously inflated prices...
  • Marc B - Friday, March 11, 2011 - link

    I am finally buying my first MacBook this year, and I am 70/30 leaning toward the 15" MBP. The 17" version has the high res screen and express port, but the 15" MBP is lighter/smaller and has the SDXC reader. Will the Thunderbolt port will provide enough throughput to allow simultaneous in/out?

    I am using this to log HD video on location, and was wondering if the express port is no longer necessary to use with a small ESATA array now that you can have high speed storage in and out using the Thunderbolt port.
  • Belard - Friday, March 11, 2011 - link

    If Apple is pushing their notebooks to be more and more Desktop replacements...

    Where is a docking bay to handle all the connectors? How hard for a single connector to handle everything?

    Lenovo sells about 3 different Docking units $130~300 for their regular Thinkpad line (ie: NOT Edge or L/SL series).

    We have a few users who use them. Comes to the office, drop the notebook into the dock and turn it on, not a single cable to be attached. They include 4 USB ports (or more), PS/2 ports, HDMI and DVI ports, Ethernet and of course charge up the battery.

    So one user would have to plug in 7 cables everyday if he didn't have a dock... like his keyboard, wireless desktop mouse, 21" display, various printers and devices, etc.
  • name99 - Friday, March 11, 2011 - link

    " I still haven't figured out how to actually grab SINR out on here, all I can see for the moment is just RSSI. "

    Apple's Airport Utility does give you part of what you want.
    If you open it, go to "Manual Setup", see the summary page, and click on where it says "Wireless Clients: 2" (or 3 or whatever) you will be given a page that, for each connection, shows their signal and noise levels (along with a graph).

    Of course this doesn't exactly have any bearing on what we are discussing, because the numbers that are presented are the intermediate term SINR values, relevant to shadowing but not to fading. The numbers that are relevant to fading (and thus to MIMO tricks) change on a millisecond time scale, and so what one really wants is an indication of their standard deviation, along with other info like the connection diversity. This is all way more geeky than Apple (or any other consumer company) is going to provide.
  • humunculus - Friday, March 11, 2011 - link

    Any chance you could run a few of the tests on the 2.0 and 2.2 GHz models. I am interested in how much performance difference there is between the 2.2 and 2.3 GHz 15 inch Macbook Pro models. It is hard to assess if the 10% cost increase is warranted. Thanks Reply
  • Belard - Saturday, March 12, 2011 - link

    The $400 price difference is for the extra 200mhz (Apple values that at $250 - these are notebook CPUs, so pricing from intel is a factor)

    And then $150 to sometimes double the performance of the GPU for games.

    Oh, and an extra 250GB of HD space (which is about $5 in the real world).

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