Booting from USB flash vs. SSD

[Carson Dyle]

I've never set up a system to boot from a USB flash drive, but I was thinking it would be convenient for a car PC that I'm considering.

How does it compare to using an SSD? Pros/cons? Is it just slower, or are there other considerations? What about the location of applications and application data files that might be read and written frequently? Could these also be on the USB stick or should they be kept on an HDD?

 

[lxskllr]

It's easy with GNU/Linux, and I have a few bootable flash drives I use. It's a bit slower, but they serve my needs. AFAIK, it isn't possible with Windows. I think you'd have to run some kind of cracked copy to get it to boot from a thumb drive. Your exact usage scenario will dictate where you put files. There's pros and cons with everything, but for routine use, a flash drive is fast enough to use as primary storage.

 

[John Connor]

I have boot from USB before and it is terribly slow. SSD is way faster. You are limited to the speed of the chipset. With SATA 2 you can see at least 280 MB/sec. With USB you are lucking to see 17MB/sec.

 

[ViRGE]

Until recently, Windows hasn't been natively USB bootable. Windows-To-Go changes that, but that's an Enterprise-only feature and is practically unattainable (Win8Ent licenses aren't sold individually). So if you're doing this then you're going to have to go the Linux route.

With that said, once you have an OS that supports USB booting then it's really not about the OS, it's about the hardware. USB flash drives are essentially low performance SSDs; the NAND is organized into a couple of channels at best (low total throughput) and is increasingly TLC NAND (lower lifetime), and the controllers are simple devices that don't take the kind of care SSD controllers do to hide latency and hold down write amplification. This doesn't mean you can't or shouldn't go with a bootable USB drive, but it means you should do your homework first. There are a wide range of USB flash drives, from the kind of awful devices I described above to drives that are essentially full-blown SSDs. Realistically you're going to find the cheapest, slowest drives to be insufferable, so you're going to want to get a more upscale drive with better performance.

However assuming you're going with a USB 3.0 capable flash drive (USB 2.0 means that throughput is capped at sub-HDD speeds of <40MB/sec), the price difference between a SSD and a USB flash drive shrinks dramatically. At that point the price premium on a SSD is roughly $10.

 

[Carson Dyle]

Thanks for all of the advice. The system would probably need to run Windows. I wasn't aware that Windows wasn't bootable from USB. I'd probably use an mSATA SSD instead.

 

[JackMDS]

http://www.rmprepusb.com/tutorials/win8togo

 

[sm625]

I've installed win xp onto a usb 2.0 flash drive. Once you get EWF enabled, it is surprisingly fast. EWF is a read-only type mode where nothing is saved. You can even make it resume from the same hibernation file every time it powers up. You can take the EWF-enabled flash drive and plug it into another windows machine and update your media library, and then plug it right back into the car-PC and it will never know the difference. It's all very cool stuff but damn it is a hassle to get set up.