Over the course of writing guides to boosting Mac and hard drive speeds, I’ve discussed the incredible performance improvements Macs can get from simple upgrades — adding RAM, choosing a fast solid state drive (SSD) as an internal or external drive, and even running a simple disk optimizer tool. But there’s a common question that comes up when considering upgrades: how can you tell in advance how big of an improvement you’ll actually see?

The answer: benchmarking tools. Many apps help you measure the speed of various components of your Mac, and with a little help, you can estimate the performance jumps you’ll see after an upgrade. Below, I’ll introduce three of the best free Mac benchmarking tools, and explain how they work…

For Hard Drive Speeds: BlackMagic Disk Speed Test

Measuring the speed of your hard drive is the easiest benchmarking process around, and the best tool I’ve found for that task is the BlackMagic Disk Speed Test by BlackMagic Design. Completely free to download from the Mac App Store, this app has only a single window and very few settings to worry about. If you have only one hard drive, you can just hit the Start button after you’ve quit all of your other apps; otherwise, you can access settings by pressing the gear button between the two speedometer circles, or use the File and Stress menus at the top of the screen. Here, you can choose the right hard drive to test, and the level of stress for the testing (1GB is least, 5GB is most).


BlackMagic designed this app to help video editors determine whether their hard drives could handle various video files, ranging from basic, low-bandwidth NTSC videos to more demanding 1080p videos with higher frame rates and color depths. Unless you’re editing video, those details (summarized in the Will it Work? and How Fast? charts below the speedometers) won’t matter at all to you. You only need to focus on the two big gauges.


The drive’s Read speed is on the right, with the Write speed on the left, respectively giving you a sense of how fast apps and videos will load, and how fast things you create will be written to the drive. Speeds in the 25-30 Megabyte per second (MB/s) range are slow — what you’d expect from an external hard drive connected via USB 2.0. The same drive placed inside an iMac, or connected via USB 3.0, could reach four or five times that speed — around 100-120MB/second.


But pop an SSD like the top-selling Samsung 850 EVO I’ve recommended into the same iMac, and these are the kind of speeds you can see: around 500MB/second, five times faster than a traditional hard drive. This is the sort of speed difference that’s dramatic, instantly noticeable, and likely to really improve your day to day Mac experience. Outstanding SSD performance is the key reason Apple has switched all of its MacBook laptops away from traditional hard drives to SSDs, and is beginning the same process with its desktop machines.


For Overall Computer Performance: Geekbench 3

Although there are a bunch of different “total computer benchmarking” apps out there, the one that’s easiest to recommend is Primate Labs’ Geekbench 3, since it’s partially free, works across multiple platforms (including Macs, iOS devices, PCs, and Android devices), and lets you compare one computer’s results to other computers and other users. Like Blackmagic Disk Speed Test, Geekbench 3 is designed to be simple to use — choose one setting, make sure your other apps are closed, and hit the “Run Benchmarks” button shown above. There’s only one hitch: the free version of Geekbench 3 only runs older (“32-bit”) benchmarks on your Mac; to see the superior performance you’d get from newer (“64-bit”) apps, you’ll need the full $10 version from the Mac App Store.


I could go into a lot of detail regarding Geekbench’s results, and there are a lot of them, sorted into three main categories, each with multiple tests. But the key numbers you need to know are the big two at the top: Single-Core Score and Multi-Core Score. Compared against results from other machines, Single-Core gives you a relative sense of how fast your Mac performs under most situations, when only one processing core is handling all of the Mac’s work. Multi-Core shows you how the Mac does when it’s being pushed to its limits and all of its processing cores are sharing a bigger workload at once.

The scores above show how my 2011 four-core iMac compares to my 2013 two-core MacBook Pro; under most circumstances, they’ll feel identical (3166 is only 3% faster than 3078), but when given big tasks to perform, the four-core iMac will deliver nearly twice the performance of the two-core MacBook Pro. Your numbers will vary a little bit from test to test; running the test multiple times will give you an average.


Geekbench offers a web-based Browser that lets you compare performance between your own machines, as well as the key hardware components found in each computer. You can see above that the differences between my iMac and MacBook Pro aren’t merely in their numbers of processor cores; look closely and you’ll note that each iMac core is faster, and the iMac has more memory. On the other hand, the MacBook Pro’s processor is newer, and its memory is faster.


The critical benefit Geekbench offers is the ability to compare your results against ones submitted by other users. Doing a search of the Geekbench 3 database for, say, “iMac 27” would let you see how various 27-inch iMacs compare with your current computer. That way, if you’re going to shop for a new Mac, you can get a sense of the Single-Core and Multi-Core performance other users are getting from their machines. Do a little math (divide the new machine’s Single-Core number by your old machine’s Single-Core number) and you’ll get a sense of the performance boost. A 27″ Retina iMac with a score of 3980 would be around 26% faster than my current machine (3166) at most tasks. That’s a big jump by Mac standards, and unlike the 5%-8% benefits typically seen in annual Mac updates, one worth paying for.

Buying an all-new Mac is a big step, though, so you might prefer something simpler and cheaper, like adding extra RAM. Although that can deliver excellent performance improvements at a relatively low cost, Geekbench’s Memory test doesn’t show you the improvement you’d get from more RAM — its benchmark only shows the RAM’s raw speed, which typically can’t be improved over the top-specced RAM Apple ships in its Macs. Whatever RAM you buy as an upgrade will match the existing RAM’s speed, but the performance improvements you see will be real, including much-reduced hard disk accessing and better CPU utilization.


For Video Card Performance: Cinebench R15

Last but not least is Maxon’s Cinebench R15, a free tool that tests two things: graphics card performance using OpenGL, and CPU performance. The CPU test shown above checks how fast your computer’s main processor can render a photorealistic 3-D scene containing 2,000 objects with lights, reflections, shadows, and shaders. This test starts with a black window and fills out the image square by square over the course of several minutes; the higher the “point” total, the faster your CPU is. Like the other benchmarks, speeds in Cinebench R15 can be reduced if other apps are running.


The more distinctive benchmark is the OpenGL test, which uses three complex 3-D cars interacting on dimly-lit city streets to test your graphics card’s ability to handle nearly 1 million polygons at once with various special effects active. It’s a cool demo to watch, and the results will be displayed in frames per second (fps). My iMac hit around 68fps, versus around 23fps on my MacBook Pro. Doing a little research online, I found scores suggesting that the demo Mac Pros in Apple Stores were getting around 77fps last year.


That’s the major hitch with Cinebench: it’s hard to meaningfully compare your numbers against other Macs unless you search Google for “Cinebench R15 score” and the specific Mac you want to compare with. Maxon does include a small sampling of different OpenGL scores within a “Ranking” box, but all that tells you is that your machine (in orange) with X cores (C) and Y threads (T) running at a given GHz speed with a certain graphics card achieved Z frames per second. This isn’t “actionable information” in that you can’t do anything with it — most people won’t even be able to tell which Macs those specs pertain to. And unless you have a Mac Pro, the only current Mac with a replaceable video card, your only option to improve graphics card performance is to buy a new Mac.

My advice: if you’re interested in improving your current Mac’s performance, consider boosting the RAM and/or putting in an SSD. CPU and GPU improvements call for an all-new machine, and Geekbench is the best way to determine whether the performance differences will be meaningful enough to justify the added price.

More Great Ways To Improve Your Mac

To make the most of your Mac (or pretty much any other Apple device), I’ve written quite a few How-To and Best of guides, as well as reviews of worthwhile accessories. Read more of my guides and reviews for 9to5Mac here (and don’t forget to click on Older Posts at the bottom of the page to see everything)!

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