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I would like to install and boot Windows from a microSD card using the Nifty MiniDrive, however, before I pay for the device and microSD card I would like to see the performance differences between different speeds of microSD cards to see if I would even want to do this. Is there any way to limit the I/O speed of windows and thus simulate running off an microSD card? Any thoughts on the performance of running off a microSD card. [Windows would only be used with VisualStudio, Visio, and some instances of 3D OpenGL graphics]

I would be installing the MicroSD card on a MacBook Pro that has a maximum speed of up to 480 Mbit/s, which is approximately 60MB/s. The MiniDrive has no restrictions on the format or speed of microSD card used within it. The limiting factor is the speed/compatibility of the SD card reader in the MacBook. MicroSD cards support read speeds of 30MB/s (16GB for $18 to 64GB for $60) and 95MB/s (8GB for $26, 16GB for $56). I would love to have the space and get the 64GB microSD card, however, wonder if it would be fast enough. Double speed or double space.

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I'd wonder if it would even boot windows first. Might be worth testing it off a normal SD card, and an evaulation copy of windows – Journeyman Geek Nov 14 '12 at 5:26
@JourneymanGeek It looks like it is possible:… – michaellindahl Nov 14 '12 at 6:54
He's using a VM software – Journeyman Geek Nov 14 '12 at 9:55
@JourneymanGeek Oo, good point. – michaellindahl Nov 16 '12 at 23:00
I asked the linked question, and was quite happy with my Windows 7 VM using a class 10 64gb SD card. I used it primarily for testing various browser setups (I did webdevelopment at the time) I too am planning on "upgrading" to a nifty mini drive w/64gb microSD in my new retina 15". – Dakine83 Mar 20 '13 at 6:50

I can't tell you about a way of testing it, but I can tell something about the performance hits. Foremost SD cards are optimized for recording movies, which means sequential write (and read). The advertised speeds are usually for sequential access. You will get the most slow-down from applications doing lots of random disk access. A compiler is one of those programs that has to read from a lot of files (even disregarding the files in your project), and will perform poorly. If your 3D rendering reads a lot of models from disk, it's the same. Web browsers are also examples of programs that do a lot of random disk access. On the whole you can say that more complicated programs, that try to conserve memory, will take a massive performance hit. There are however SD-cards with exceptional random access performance, usually single level cell architectures. They don't come cheap. A good USB flash drive or small external HD might be a good compromise for costs, performance, and ease of use.

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Hmm. There are ways of simulating a slow processor, and ways of simulating slow network, but simulating slow disk appears to be outside the realm of most things people consider doing when working on machines.

The closest thing I can find is slamming the disk with read/write cycles, but that of course isn't very accurate.

Generally speaking, there aren't many issues with running an OS off of an SD card. There might be some concerns with longevity of the disk if it is used for swap space or log files that are constantly modified. The biggest issue you'll notice is initial load times are longer, simply because the disk does have limitations on speed. Once in a Windows environment it will have pulled necessary items into memory and chug along just fine. If a development environment is all you need out of this install it should work fine for your purposes.

Look for class 10 cards (class is the speed rating), and shy away from the dirt cheap class 4 cards. Some of those manufacturers like to fudge the numbers.

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