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SATA Generation

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Hi, can someone confirm the SATA generation on the BananaPi. I know its gen 2 on the BananaPro so could someone please confirm?
tkaiser  
SATA is part of the used A20 SoC both Pi/Pro are using. It's SATA Revision 2.0 but the A20 is not able to saturate the link (40/200 MByte/sek write/read)

so what real world performance would you likely see

tkaiser  
markbourke7 replied at Sun Dec 14, 2014 11:14
so what real world performance would you likely see

As already written: writes approx. 40 MB/sec, reads max out at 200 MB/sec. On platforms that use a small ARM SoC everything depends on different factors so you might simply search the forum for measurings: https://duckduckgo.com/?q=iozone+site%3Aforum.lemaker.org

Well, that is still much better than SD card speeds

tkaiser  
mikronauts replied at Sun Dec 14, 2014 12:40
Well, that is still much better than SD card speeds

Of course, especially read performance. But if you think you can saturate SATA 2 link speeds you're lost with A10/A20. If you need faster write speed then you would have to choose Freescale's i.MX6 (I measured 85/100 MB/sec write/read with my WandBoard Quad a year ago with a very crappy Yocto image so performance might be better) or even better Marvell Kirkwood/Armada370 when you want to stay in ARM country.

tkaiser replied at Sun Dec 14, 2014 14:38
Of course, especially read performance. But if you think you can saturate SATA 2 link speeds you'r ...

I did not expect to saturate the SATA, and it is still a very nice step up from SD

I use more powerful boxes when I need the bandwidth - my video editing box has an SSD for OS/boot, and four striped 7200rpm 1TB SATA3 drives for the video files.

That box (3.8GHz eight core AMD) has ridiculously fast read/write bandwidth for large contiguous files, as I recall testing showed somewhere around ~800MB/sec (far more than needed for uncompressed 1080p) .. I split the array across two SATA3 controllers on different PCIe lanes.

tkaiser  
Edited by tkaiser at Mon Dec 15, 2014 00:14
mikronauts replied at Sun Dec 14, 2014 18:18
I did not expect to saturate the SATA


Unfortunately some others do

They read the specs and confuse link speeds with real world throughput (applies to GBit Ethernet too especially when both are used concurrently).

BTW: Regarding your stripe set: If you fill up the array completely I would assume write speeds will decrease below 500 MB/sec due to ZBR...

tkaiser replied at Mon Dec 15, 2014 00:12
Unfortunately some others do

They read the specs and confuse link speeds with real world throu ...

Yep, however fortunately even 500MB/sec is more than I need for my purposes

Raw 1080p needs about 360MB/sec @ 60Hz, so I am good.

Good thing I am not trying to edit 4k video though! At 60Hz that would take ~1.44GB/sec for raw frames.

Edited by markbourke7 at Fri Dec 19, 2014 11:19

sorry for the late reply. i have done a few tests and when transferring a 1GB it takes about 5 mins writing the file to the NAS and when reading the same 1GB file it takes about 3 mins. the read speeds are min 2.4 MB/s read max 5MB/s and 5.7MB/s write. can anyone explain why this is so slow? SATA 2 bandwidth cap is 300MB/s and i'm on a laptop right beside the router with 802.11 b/g/n on the 2.4GHz range and the bandwidth cap on that is anywhere from 6.75MB/s to 75 MB/s and my HDD is a 7200 rpm hdd???? i didn't know it would be so slow

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