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#1 2016-05-18 15:28:28

ap
Member
Registered: 2016-05-18
Posts: 2

Terrible storage writing performance with Odroid C2

I recently bought an Odroid C2 board from your store, and I'm experiencing some terrible performance while writing to any kind of storage media. I'm running Arch Linux ARM from a Kingston SDC10G2/64GB UHS-I SD card (formatted in ext4) and I get the following performances compared with my main Arch Linux machine:

  • External Toshiba HDD (ext4) via USB2: 1.4 MB/s vs ~36 MB/s

  • Kingston DataTraveler 4GB pendrive (exFAT) via USB2: 16.1 MB/s vs ~40 MB/s

  • Synology NAS (Samba share) via Ethernet: 11.5 MB/s vs ~25MB/s

  • SD card (ext4): 12.9 MB/s

These were simple benchmarks made with:

dd if=/dev/zero of=tempfile bs=1M count=1024

and are thus approximate upper bounds for the raw performance, since I didn't have dd sync before exiting.

I know that ARM platforms tend to have worse storage performance than desktop computers, but this seems too much degraded, and I couldn't find any similar complaints while searching online. Do you know how I could try to debug this issue?

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#2 2016-05-18 18:10:03

Diigiit Sales
Member
Registered: 2014-05-26
Posts: 99

Re: Terrible storage writing performance with Odroid C2

Well, maybe the first test I would do is similar to what Hardkernel did e.g. :

Write speed command : 
$ dd if=/dev/zero of=test.tmp oflag=direct bs=8M count=64

Read speed command : 
$ dd if=test.tmp of=/dev/null iflag=direct bs=8M count=64

and compare your own results with Hardkernel on the Odroid-C2 page.

If you have the same performance than Hardkernel but think it is still too slow for your application, try the eMMC module that is 7 times faster.
If you Odroid-C2 is significantly slower than Hardkernel test, you should try to isolate the culprit.

I am suspecting (but don't have any proof) that some hardware may be better supported by Hardkernel (like Sandisk memory card) than others. I guess also that Hardkernel did some fine tuning of the Linux kernel to get the best performance out of the official distribution they are providing.

So if previous test shows that you have far different performance that what Hardkernel got, I would try to isolate the possible culprit:
- distribution: test with official Hardkernel image and Arch Linux
- microSD card: test with your microSD card and with Sandisk card

P.S. I can remember a customer having awful performance. The problem was due to the memory card. He was able to make some changes to fix it. It was on an Odroid-XU4 if I remember well.

Last edited by Diigiit Sales (2016-05-18 18:29:50)

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#3 2016-05-18 23:19:22

ap
Member
Registered: 2016-05-18
Posts: 2

Re: Terrible storage writing performance with Odroid C2

Diigiit Sales wrote:

Well, maybe the first test I would do is similar to what Hardkernel did e.g. :
(snip)
and compare your own results with Hardkernel on the Odroid-C2 page.

Thanks for mentioning those commands! I repeated the benchmarks, taking the average of 5 runs for both reading and writing, and the results seem to be more clear. Namely, I'm getting almost the same performance on the C2 and on my Arch machine both from the SD card and from the USB flash drive, but not from the USB hard drive. Since this drive is USB powered I tried an old one via a SATA to USB adapter with external power, and that one had the same performance as on my main machine.

Currently I'm powering my C2 via a micro-USB cable (from a 5V/2.1A source) and this might be the reason why my drive isn't getting enough power. I'm still waiting for a DC cable that I ordered, and I'll try again once I have it.

Last edited by ap (2016-05-18 23:20:29)

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#4 2016-05-19 12:00:37

Diigiit Sales
Member
Registered: 2014-05-26
Posts: 99

Re: Terrible storage writing performance with Odroid C2

Ok, I didn't realize that you were using an external drive. I thought you were talking about your desktop computer smile

I am not sure that powering your external hard drive with a different power supply will improve the performance. My idea is that if hard drive is not getting enough power, it will not work at all. I suspect USB 2.0 port is the culprit. For this reason, many customers prefer to use Odroid-XU4 equipped with USB 3.0 port for USB video camera for instance. Transfer rate is higher.

I guess you need to use an external drive because you have more than 128GB is data to access.

Last edited by Diigiit Sales (2016-05-19 12:04:06)

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