Using an SD card as a Windows Partition

NewishMacGuy

macrumors 6502a
Original poster
Aug 2, 2007
636
0
The Need:
Unfortunately, I need to use Windows to run Bloomberg Pro and some decently large models that pull both live and static data from Bloomberg BDP calls. Speed is important, but not crucial. It can be done in a VM, and that's my preference, but from time to time I may want to boot from Bootcamp as well.

The Plan:
Get a 16GB/256GB rMBP + 400x 128GB SDXC card. I only use 120GB for all my non-Windows stuff, so a 256GB drive should leave me with room enough to grow. The Windows stuff will be much less than 100GB, but I'd like to have more than 64GB dedicated to a Windows partition. Was thinking I could partition the card as a Windows drive, put Win 7 and the Windows software on it and use it for both Bootcamp and with Parallels 8.

The Reasoning:
I don't need (nor do I want to pay $500 for) the 512GB Apple flash drive upgrade. I do want a little extra space to separate Windows from my OSX hard drive completely. And I'd like to have it be very portable (more portable than a portable external HD). Thus, I thought that using an SDXC card would be ideal.

Anyone done this? Any thoughts on whether or not it'll be fast enough? Any other downsides of which I should be aware before diving in?

Thanks for the advice.
 

bogatyr

macrumors 65816
Mar 13, 2012
1,127
1
I run another instance of OS X off a 128GB Sandisk SD card. Boots OK, but now and then the system pauses due to the SD card speed. This is in a rMBP 2.6/16/512.
 

NewishMacGuy

macrumors 6502a
Original poster
Aug 2, 2007
636
0
I run another instance of OS X off a 128GB Sandisk SD card. Boots OK, but now and then the system pauses due to the SD card speed. This is in a rMBP 2.6/16/512.
Thanks for that real world experience.

Just read Anandtech's review of the SD card slot on the new rMBP and he was getting 80 MB/s reads and 40 MB/s writes which should do well enough. Theoretically, the UHS-I speed standard can currently get up to 100 MB/s reads, which (I think) is like a 5400 rpm drive on SATA 2 (but with lower seek time) and that should be OK as far as speed goes.

I am somewhat concerned with the number of writes limitation though, I won't be writing a lot, to the Windows partition, but Windows 7 itself might.
 

NewishMacGuy

macrumors 6502a
Original poster
Aug 2, 2007
636
0
I run another instance of OS X off a 128GB Sandisk SD card. Boots OK, but now and then the system pauses due to the SD card speed. This is in a rMBP 2.6/16/512.
BTW, are you running the Class 10 (133x) or UHS-1 (400x) card?
 

Exana

macrumors regular
Mar 15, 2011
219
0
Windows will not install on SD card. It needs PATA, SATA or SCSI device.
 

bogatyr

macrumors 65816
Mar 13, 2012
1,127
1
BTW, are you running the Class 10 (133x) or UHS-1 (400x) card?
Ok double checked. I was using a 64GB UHS-I Class 10 microSD card from Sandisk. Sandisk rates it at 30MB/s. This one lags a lot.

I tried my 128GB UHS-I Class 10 full size SD from Sandisk. This one is rated at 45MB/s. Works without lag after indexing finished.

EDIT:
64GB card I used:
http://www.sandisk.com/products/memory-cards/microsd/ultra-class10-for-android/?capacity=64GB

128GB card I used:
http://www.sandisk.com/products/memory-cards/sd/extreme-uhs-1-45mbs/?capacity=128GB
 

boombashi

macrumors regular
Feb 4, 2005
232
26
Windows will not install on SD card. It needs PATA, SATA or SCSI device.
This is true. I can confirm you cannot install windows on an external drive. You can however install parallels and keep your windows image on an external, but not really the same thing.
 

NewishMacGuy

macrumors 6502a
Original poster
Aug 2, 2007
636
0
Ok double checked. I was using a 64GB UHS-I Class 10 microSD card from Sandisk. Sandisk rates it at 30MB/s. This one lags a lot.

I tried my 128GB UHS-I Class 10 full size SD from Sandisk. This one is rated at 45MB/s. Works without lag after indexing finished.

EDIT:
64GB card I used:
http://www.sandisk.com/products/memory-cards/microsd/ultra-class10-for-android/?capacity=64GB

128GB card I used:
http://www.sandisk.com/products/memory-cards/sd/extreme-uhs-1-45mbs/?capacity=128GB
Thanks bro. That's great color. That means that the Nifty MiniDrive flush-mount solution is not workable until the microSD cards get a speed bump. But it sounds like if you're willing to have the card stick out a little, a 133x Class 10 card will do and a 400x UHS-1 card could be decent. That's a big help.

Here's to hoping that next year will see advances in the microSD and we can put Windows on a Nifty to keep our OSX drives untainted with that hot mess, but still flush mounted for portability.

----------

This is true. I can confirm you cannot install windows on an external drive. You can however install parallels and keep your windows image on an external, but not really the same thing.
Ok, this is what I did with the old iMac. I can give up native Windows boots in order to keep it off my main HD.
 

dagamer34

macrumors 65816
May 1, 2007
1,359
101
Houston, TX
Thanks for that real world experience.

Just read Anandtech's review of the SD card slot on the new rMBP and he was getting 80 MB/s reads and 40 MB/s writes which should do well enough. Theoretically, the UHS-I speed standard can currently get up to 100 MB/s reads, which (I think) is like a 5400 rpm drive on SATA 2 (but with lower seek time) and that should be OK as far as speed goes.

I am somewhat concerned with the number of writes limitation though, I won't be writing a lot, to the Windows partition, but Windows 7 itself might.
You should ignore sustained reads and writes (the numbers you are quoting) because the operating system almost never does those kinds of I/O operations on the system drive. Instead, you need to look at random 4K sector reads and writes which happen from dealing with tiny files, and SD cards as well as mechanical hard drives are terrible at those operations compared to SSDs.

As such, having OS X on an SD card might be fine for a backup, but I wouldn't use it more than required.
 

bogatyr

macrumors 65816
Mar 13, 2012
1,127
1
As such, having OS X on an SD card might be fine for a backup, but I wouldn't use it more than required.
I would agree with this. My SD card OS X if for when I'm without my laptop and I have access to another Mac. It's easier to have my config all set instead of using someone else's. Though - it is rare I don't have my rMBP on me.
 

bugout

macrumors 6502a
May 11, 2008
710
27
is everything!
This is true. I can confirm you cannot install windows on an external drive. You can however install parallels and keep your windows image on an external, but not really the same thing.
You are 100% wrong. I have windows installed on an external TB SSD just fine.
 

mgalekgolo

macrumors newbie
Oct 28, 2012
3
0
I can confirm that windows 7 can be installed to a flash drive. I put it on a cheap 8 gig flash drive for testing. I followed some tutorial online, mostly using Fdisk and other CMD utilities. Holding option during boot, the computer recognized it.
 

muellmailer

macrumors newbie
Sep 7, 2016
1
0
I can confirm that windows 7 can be installed to a flash drive. I put it on a cheap 8 gig flash drive for testing. I followed some tutorial online, mostly using Fdisk and other CMD utilities. Holding option during boot, the computer recognized it.
Hi, where can i find the tutorial to install windows on usb thumb drive or sd card?
Many thanks
 
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