Back to the Mac: OS X 10.7 Lion Review
by Andrew Cunningham, Kristian Vättö & Anand Lal Shimpi on July 20, 2011 8:30 AM ESTFileVault Performance
With Lion sporting a more usable version of FileVault I was curious about its performance impact. I'd enabled FileVault on my personal machine and subjectively felt a performance impact, but I needed to quantify it. I put together a number of tests to do just that.
For all of these tests my test platform is a 15-inch MacBook Pro with a 2.2GHz Sandy Bridge Core i7 from early 2011 with an Apple branded 256GB SSD. In these tests I was primarily concerned with two things: how performance is affected, and what sort of extra load FileVault encryption places on the CPU.
Our first test is a simple file copy. I've got a directory of 2200MB worth of RAW files from a Nikon D700. I copy the folder from the SSD to the same SSD and report performance in MB/s:
With FileVault enabled we take a 24% performance hit, hardly insignificant. Average CPU utilization during the file transfer actually dropped with FileVault enabled from 8.5% to 4.5%. I suspect the reason for the drop was the slower overall transfer rate. It would appear that FileVault, at least on a quad-core Sandy Bridge CPU has absolutely no overhead here. Given that Apple near-universally uses AES for symmetrical encryption, it's reasonable to assume here that FileVault is taking advantage of the AES-NI instructions on Intel's Core-i series of processors.
Our next test tested one of Lion's new features: threaded conversations in Mail. We timed how long it took to launch Mail and open a single email thread with 42 replies. If you've used OS X Mail in the past you'll know that CPU utilization goes insane if you're working on a thread with dozens of replies. The same is definitely true for threaded conversations in Lion.
Thanks to the MacBook Pro's SSD both setups complete this task pretty quickly. There is a penalty associated with FileVault though - around 9% in this case. Peak CPU utilization was similar on both systems, 100% of four threads on the eight thread Core i7.
I grabbed a screenshot of the CPU utilization graph in Activity Monitor during this test for both setups:
CPU Utilization: No Encryption (left) vs. FileVault Enabled (right)
While the two vary slightly, you can see that overall CPU utilization appears to be similar regardless of whether or not encryption is enabled.
Our third test is actually one of our standard OS X CPU benchmarks - we time the import of 203 RAW images into iPhoto. This task is impacted by both CPU and I/O performance:
Despite the I/O dependency, there's virtually no performance impact to enabling FileVault here.
Our final tests are raw I/O tests using Quickbench. I focused on 4KB and 8KB random read/write since those are the most common transfer sizes for random file access. And for sequential operations I focused on 128KB transfers, again optimizing for common sizes.
Overall the hit on pure I/O performance is in the 20 - 30% range. It's noticeable but not big enough to outweigh the benefits of full disk encryption. Note that under OS X there's still no way to take advantage of SSD controllers with FDE like the SF-1000/2000 series and the Intel SSD 320.
Facebook
Twitter
RSS
106 Comments
View All Comments
khimera2000 - Wednesday, July 20, 2011 - link
that's pretty neat. It looks like it adds in a bunch of interesting features. The one trend I do see it that both mac and M$ are driving components from there mobile platforms into there desktops. I don't mind if they do this, but I still want a different feel between devices.As for the complaints and shouts of if its a service pack that should be free, or if its an update worth 30 bucks. On this subject I think that there is no comparison, M$ has a setup that benefits its use of massive volume licencing, but the option to pay for service packs makes sense for a company that does not dominate 90% of the market, but want to maintain more talent to add more features. I know that some people might take offense to this, but its my opinion so screw you.
Still confused on the full screen thing, I can move between applications easily, with all of them in full screen, its called ALT+TAB, or Win+Tab, or CTRL+TAB (when you want to cycle through your web browser only. so the entire portion where he says its a advantage over win (this feature) makes me confused, then again i'm a big fan of keyboard shortcuts, so i could be missing things. I'm hoping that the full screen feature pans out. I am considering getting one, but not till they leave the OSX family. (still hate the way it came to be >.<)
the movement away from CD is great, here's hoping that there are plans in the works for all software to be distributed like this, because... I cant remember the last time i walked into a store and asked myself what program do i need...
Over all it was a interesting read.
chenedwa - Wednesday, July 20, 2011 - link
I just installed Lion on my circa 2009 MBP 2.53GHz C2D. I then tried to download the latest Parallels update via WiFi using Firefox 8 beta and was getting phenominal transfer speeds of more than 900kB/sec for the 203MB download! Wow!Uritziel - Friday, July 22, 2011 - link
None of that sounds wow worthy...Uritziel - Friday, July 22, 2011 - link
Or applicable to the article...ThreeDee912 - Wednesday, July 20, 2011 - link
About future support for the white MacBooks, it appears that Apple has silently discontinued them. They're nowhere to be found on the Apple Store website.Engadget also reported that they received word from Apple that they really were discontinued:
http://www.engadget.com/2011/07/20/the-macbook-dro...
secretmanofagent - Wednesday, July 20, 2011 - link
"Also missing is the button in the upper right-hand corner that would invoke icon-only view - those of you who use it will have to become acquainted with Alt+Command+T, a keyboard shortcut that toggles this change."Should be Command-Option-T.
SmCaudata - Wednesday, July 20, 2011 - link
So with my early 2008 Mac Book I already took a hit to batter life with Snow Leopard. In fact, I just got a new battery and after a couple of months the health reads at 80%. I have seen other's with this issue but the posts often get deleted on the main apple forums. Now I would take another hit to upgrade to Lion?I really liked my MacBook Pro when I got it, but this blatant disregard for current customers in a push to get people to upgrade is ridiculous. My laptop has plenty of power for laptop tasks. I don't need to upgrade hardware for performance reasons.
Remember how much crap Microsoft took for making Vista a system hog on older systems? Do you think that Apple will ever see anywhere near the rage?
name99 - Thursday, July 21, 2011 - link
Then don't upgrade.What are you so angry about? Your mac will work just like it used to. Apple will continue to provide security and other updates for at least three years. You'll get iTunes and Safari updates. What's the problem?
If you find you HAVE to have some Lion feature, sell your MacBook on eBay --- you'll get a surprisingly good price.
MonkeyPaw - Wednesday, July 20, 2011 - link
The 64 bit support isn't entirely an Apple issue. It is Intel that treats 64 bit as a feature to be hacked out of CPUs on a whim to make them "cheaper." It just bugs me the way its been handled by everyone but AMD. 64bit sure looks like the future, but here we are dragging our heels on support.Anyway, does OSX support SMT? I thought that it didn't, but I see the latest specs of hardware with the 2/4 core/thread configuration.
tipoo - Thursday, July 21, 2011 - link
Ehh? SMT is a processor feature, OSX will use as many cores (real or virtual) as you can throw at it.