# Booting from an SD card.

I'm finally getting a new computer that actually has an SD slot. What I'm wondering is: are SD/flash cards are faster than a 5400rpm hard drive? And, is it possible to boot from a SD card? Basically, I'm thinking it would be a poor man's SSD.

Also, is there a way to set windows to use a different drive for programs than the drive it uses to boot? I wouldn't want to limit the amount of programs I could install to 32GB.

in terms of using an Secure Digital High Capacity Card for a hard drive, Possible yes, recommended no.

Yes! It is possible to boot from an SD card, change your bios settings to boot from usb/flash/external.

SDHC Class 10 runs at 45mb/s (currently the fastest SDHC card)
Sata 2 (3.0gbit/s) 5400 RPM drives run at a maximum of roughly 1-90mb/s
USB 3.0 (3.2-5gbit/s) drives run at approx 75-320mb/s
Sata 3 (6.0gbit/s) 7200 RPM SSD's run at roughly 400-600mb/s (depending on quality)
Using the above data your best bet for a "cheap mans SSD" would be a USB 3.0 flash drive of sorts, but in all reality you wont really notice much difference unless you spend a hell of a lot on a external SSD defeating the purpose of the SSD by limiting it to usb but there really isnt much point in that unless your planning on taking your windows installation with you instead of in your pc.

To set windows installations to default on another drive is quite simple,
windows key + R, type in regedit push enter.
navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
Change the Path in ProgramFilesDir and ProgramFilesDir (x86)
this will make it so by default your programs will install to another location of your choosing. x86 will only show if you are using 64bit windows.

Oh and if your thinking about raiding multiple 4gb flash/sd cards together yes thats strangely possible too, although the outcome is still no where near the results of an SSD

the below link shows 6x 4gb flash drives USB 2.0 getting a maximum of 75mb/s averaging 45mb/s still the same speed of the class 10 SD cards. and not even a 10th of what you get on an entry level SSD.
http://analogbit.com/node/4

So to answer your question, yes you can do everything your speaking of, although you would need roughly 109 usb 3.0 devices in raid 0 to even come close to the speed of an SSD (judging at 550mb/s) and even then the chance of one of them corrupting and requiring a full rebuild is extremely high, plus this would be going a tad insane just to set up, not to mention would cost more then the most expensive SSD to set up haha.

i would do it for fun and see how it goes(SD card not 109 usb drives) but i wouldn't recommend using it as a main OS install.

SSD prices have shot down quite a lot over the past few months, for example you can get an SSD for $59 AU OCZ Agility 3 60gb Max read up to 525MB/s, max write up to 475MB/s will be a hell of a lot faster then a 5400 drive and even a 7200 drive for that matter, i currently have one of these in my personal gaming computer, i paid$120 at the time last year in april. link below is of the ocz agility 3 60gb
http://www.pccasegear.com/index.php?main_page=product_info&cPath=210_902_909&products_id=17344

You will not regret spending a little bit extra to reap the rewards of an extremely fast storage device.

I would just get an SSD and be done with it, but I'm getting a laptop and a laptop with 2 drives is out of my price range. I can't use an SSD as my only drive because I've read too much about how too many writes cause them to slow down. It would be nice as a boot/OS drive (which are relatively constant and don't involve many writes/erases), but I'd be beating my self up over every useless download/copy/compile/etc.

I'm not too concerned with run time performance. With a reasonable amount of memory and a good processor that's never really going to be a problem. Not for me at least. A second or two to open an app hasn't really ever bugged me yet. It's just boot time of my old computer that's always annoyed me (~1 minute). That's the only reason I'm considering this. How long is the boot time for your gaming computer?

my boot time using the same mobo with a 7200 1tb drive was around 3 minutes, when changing to the ssd boot times went to 6 seconds and after using windows for the past year or so boot times have gone up to 13 seconds, due to loading a few more things and the age of the ssd i guess.

Have you looked into Hybrid drives? they are half and half basically, i was wrong to just assume you where talking about a desktop computer, laptops SD cards are still limited by usb 2.0 regardless but now that you have the issue with two hard drives or the one rather. i would definitly suggest looking into hybrid drives as they are SSD for constantly used programs inc windows ect. and offer larger storage capacity meaning you dont have to worry about running out of space (personally im having this issue at the moment due to not changing my install directory)

500GB Seagate 2.5" 7200rpm Momentus XT Hybrid Notebook SATA 6Gb/s HDD $149 AU http://www.computeralliance.com.au/parts.aspx?qryPart=11744 [Broken] Another idea is to just use an SSD for your windows installation and use an external hard drive for all your files. for example$55 for a 60gb SSD and say $94.95 for a 1TB external$149.95

one dollar extra, takes more space but has twice as much storage. both viable options upto personal choice.

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Wow, 6 sec, that's crazy. I haven't got my laptop yet, so I'll see how fast the boot time is with it and see if the \$150 is worth it. I might still be a little OCD about writing, because AFAIK, I have no control over what is done with the internal flash cache and how often it is written to, but I suppose that if the boot time is bad enough, I could get over anything.

Thanks for the info and suggestions.

Now to make it sound less flattering, the 6 seconds is only the Windows loading time. as in from end of bios to full load with explorer/my computer open using windows E. i am currently limited by the bios speed itself as i have a cheapo motherboard that i cant disable onboard sound due to it then in turn disabling my first PCiE x4 slot meaning my sound card doesnt work ironically. so yes 6 seconds of a clean install of windows is possible, now that my hard drive is close to being full due to not installing onto another drive for programs and so forth, my boot times are alot slower sadly. so i would definitly suggest setting up a seperate drive for installing programs to as you originally thought of.

And im very glad that i've helped you

Oh also i am talking about windows 7 for reference sake, i couldnt imagine how fast windows xp would load hahahaha that would be insane!!!