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I'm planning to set up a FreeNAS box for home use, and would prefer to boot from a USB flash drive. The hardware I'm considering doesn't have USB 3.0, but I'm doubtful it would make a difference: once the OS loads into memory, will it need to read much off the USB drive? Other than the initial boot-up time (which I don't care about) is there any reason I would want to install a USB 3.0 card in it and use it for the boot drive.

(I'll probably install one for use with external platter drives anyway, but all I'm asking about in this question is how it would affect my boot drive.)

iconoclast
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3 Answers3

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Well, the whole OS does not load into RAM as far as I know.

Anyhow, according to this, maximum USB 2.0 bandwidth is 60MB/s but no generic flash drive is close to that yet.

So, the answer is no, you will see no difference between USB 2.0 and 3.0 for flash drives.

EDIT

As babca said, 60MB/s is theoretical speed of USB 2.0. In practice, it is around 30MB/s according to this. I have done some research and found that there are actually some flash drives that go beyond USB 2.0 speed. (did not know because none of them are sold in my country, and also all are too expensive yet)

Focusing back on your question, the answer is still no in my opinion. Because I don't think you will ever use the 32MB/s transfer rate for home use. (you should actually define that home use you said there).

I assume the maximum transfer rate you will need is watching a Blu-Ray film, unless you have a super duper over-240Mbit/sec internet connection bandwidth. Blu-Ray disc's read mechanism allows 4.5MB/s only, so I assume you will be able to watch quite fine.

Conclusion:

You will see little to no benefit from USB 3.0 transfer rate for home use. Adding the over-price of USB 3.0 flash drives to the equation concludes that sticking to USB 2.0 is fine.

Community
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Etherealone
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Answer is very likely no.

I use Openmediavault and a few XBMC boxes (OpenELEC, raspbmc) from SD cards and tried different SD cards/flash drives/SSDs, the performance differs by boot time only. Once an application is started, it operates in RAM. It should be the same with FreeNAS.

Another story would be activity logging and other read/write activities which are performed while OS running (for example if you have MySQL plugin+MySQL installed).

Tolga Hoşgör: In real usage, maximum USB 2.0 transfer rate (with modern chipsets) is ~32MB/s, which could be a bottleneck for some very high speed drives. Usually only USB 3.0 or eSATA flash drives are limited in speed when connected to USB 2.0 connector, because pure USB 2.0 drives typically don't include memory chips faster than ~35MB/s.

babca
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I am testing with ssd over usb connector on my nas. I will update on how this works as I am sick of the thumbs failing ...had it up for 3 years and have replaced them on sets of 2 7 times

Kenneth nicklowicz
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