neurotico
Posts: 5
Joined: Mon Feb 27, 2017 1:37 pm

Comparing SD Cards - Benchmarked

Mon Feb 27, 2017 10:32 pm

Hello,
So after getting my RasPi3, and semi-impressed with the speed of the included Micro SD card, I decided to compare it with a few others I have...these are no generic crap cards rest assured.
To setup this test, all hardware other than the micro sd cards was identical, no changes in accessories or software. The micro sd cards were setup by downloading Noobs, installed and ran through the setup up to the same point, which was all updates installed and only admin user created. :ugeek:

I used the following command as my benchmark base:

Code: Select all

dd if=/dev/zero of=/tmp/out bs=1M count=400
Let me mention, the purpose of this test was to compare the speed of the RasPi3 bootup and reboot, with different micro sd cards. I have not run the numbers to compare speeds of moving small and large blocks, or sequential and non-sequential blocks from within the OS to a peripheral. That test would be useful, but only for those constantly moving files to or from attached storage and is not my use scenario as I was more interested in fastest boot times.

Below are the names, model numbers and links to the product page to the various micro sd cards I tested. Mainly I chose these models because I had them already for action cams, drones, DSLR, etc.
Boot times were clocked with a digital timer linked to a power source. When I flipped the switch, power activated to the RasPi3 and to the timer. The timer was manually stopped upon reaching the logon screen prompt.
Reboot times were achieved by first performing a clean boot to the OS, entering the password and waiting 3 minutes with no use just to ensure all services were running and all wireless signals connected. Then the restart button was pressed with linking the timer to the keyboard. When I pressed 'Enter' it initiated the timer and sent the command to RasPi3 to restart. 8-)

Now for the numbers!!! ;)

I will list the SD Cards and results in this manner:
1) Micro SD Card Model, Speed-Class Rating, UHS Speed-Class Rating - Current Price on Amazon
Product Page URL
Bootup Time - Reboot Time - Transfer Size, Transfer Time, Transfer Speed
(results from command provided).

1) 8gb, C6, U0 (included with Rasberry Pi) - $12.78
https://www.amazon.com/Raspberry-Pi-Pre ... ords=noobs
14 seconds - 16 seconds - 419 mb, 46.79 seconds, 9.0 mb/s

2) PNY 64gb, P-SDUX64U1-GES3, C10, U1 - $28.38
https://www.amazon.com/PNY-Professional ... DUX64U1-GE
19 seconds - 22 seconds - 419 mb, 17.96 seconds, 23.4 mb/s

3) Panasonic 16gb, C10, U3 - $53.49 (included w/ DJI Phantom drones)
https://www.amazon.com/Panasonic-16GB-m ... APanasonic
16 seconds - 27 seconds - 419 mb, 23.47 seconds, 17.9 mb/s

4) Sandisk 64gb, C10, U3 - $51.90
https://www.amazon.com/gp/product/B010N ... UTF8&psc=1
14 seconds - 16 seconds - 419 mb, 14.95 seconds, 28.1 mb/s

:o :shock: :o :shock: :o :shock: :o :shock: :o :shock: :o :shock: :o :shock: :o :shock:

Conclusion:
First thing to note: the cards are not relevantly 'faster' just because they are rated higher speeds. These speeds are calculated with including burst read/write speeds and each manufacturer may vary on how badly they exaggerate these numbers. Unfortunately, there is no "Department of Flash Memory Speed Standards" with soldiers on the ground to fine or arrest any such entities that claim their cards are U3 compliant...but only writing at 30mb/s...such as the Sandisk :roll:

Second thing: the burst speeds are not the most relevant with this use type. The most important thing to look at here is the 'Sustained read/write speeds'. Now in this test it was not so easy to show those numbers, nor was it the purpose of this article. The purpose was simply to find the fastest boot times. I will be running speed tests between these cards with large/small files and sequential/non-sequential files, to compare against what they claim it can do.

Last thing: as you can see from the tests above, the best overall card was the Sandisk...even though it was far slower than its claimed speeds. Tied with the micro sd card that came with the RasPi3 in boot & restart times, it does have a significantly higher read/write performance after it is running. Clearly the winner! But is it worth it? My opinion is no. Why will you spend $50 for a card that only performs nearly the same? If the purpose is storage, this is not the solution. Connecting an external drive to your wireless, or directly to the RasPi3 USB will be the right solution for local storage. If it is for a VM, or a database or service that requires everything to be local primary drive, then you may need to consider investing in a larger micro sd card.

To select the right card for your use, please ask yourself this question: do you want the RasPi3 to startup fast and be slower using it, or slower to startup and faster using it?
If your goal is pure boot times, find the card that has the highest burst speeds and typically these will be the higher capacity cards. But if you want better performance inside the OS, go with one that better sustained read/write speeds.

I hope this has been a helpful write-up to some and entertaining to others. I learn each day, I'm looking forward to hearing back from many of you and learning more from you.

Thank you and cheers!
John

fruitoftheloom
Posts: 19811
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Comparing SD Cards - Benchmarked

Mon Feb 27, 2017 10:44 pm

adieu

My other Computer is an Asus CS10 ChromeBit running Chrome Operating System.
HP Envy 4500 Wireless Printer supported by HPLIP software in Raspbian Buster.
Raspberry Pi Model 2B v1.1

neurotico
Posts: 5
Joined: Mon Feb 27, 2017 1:37 pm

Re: Comparing SD Cards - Benchmarked

Tue Feb 28, 2017 4:16 am

My soul just cried a little. :shock:

gkreidl
Posts: 5953
Joined: Thu Jan 26, 2012 1:07 pm
Location: Germany

Re: Comparing SD Cards - Benchmarked

Tue Feb 28, 2017 7:37 am

Before you pay more than 50$ for a SD card, get a USB HDD (preferably a 3.5" one with separate power supply) and move the file system to the HDD. Better performance, Terrabytes of disk space available.
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neurotico
Posts: 5
Joined: Mon Feb 27, 2017 1:37 pm

Re: Comparing SD Cards - Benchmarked

Tue Feb 28, 2017 3:31 pm

I tried to do that...offload the OS to external devices...tried with USB drive and USB external disk, also tried with an ethernet attached external disk, but none worked to boot off of. I didn't research it much, presuming the same as with most OS's that cannot be ran as such, unless it is the OTG version, but I don't see a "Noobs/Raspbian OTG". If that is possible though, I might consider tested the speed of it...doubt there is any improvement in performance however, especially being the USB ports are 2.0.

Fastest theoretical speed is 480 mbps...but when considering the average speed of flash drives are about 20 - 30 mbps, we would need to invest in a much better one to see good performance.

Micro SD cards are around that same, 20 - 30 mbps, as operating inside of Raspbian. Of course we can select much faster cards here as well.

So what is the best way to expand storage, maintain performance and with the minimal cost?
Consider all these things we've talked about to make your own decision in the matter, only you knows what will be the best for your needs.
-how much storage do you need
-do you want a faster boot/reboot time and slower OS, or slower boot/reboot time and faster OS?
-do you have a USB port available with all peripherals attached?
-does your router/switch have a USB port?
-do you use WiFi or Ethernet?

These questions can quickly point you to the right direction and show you the options you have. Because if you have a few peripherals already without another USB port available, then don't consider a USB drive or USB external disk. You could purchase a USB expansion, to provide more USB ports...but now you are degrading the speeds and adding cost...defeating both purposes. But if you are on WiFi, then your Ethernet port is another option...either connect to a LAN with a shared disk/drive, or connect an adapter Ethernet to USB and attached an external drive/disk to it.

Personally I have a hybrid setup of many of these options with drives on the LAN and on a separate subnet that I VPN into, which serves as my 'offsite redundant backup', a media server connected to the Ethernet port, printer and other peripherals to the USB ports and a wireless keyboard/mouse receiver.

Ultimately everyone sees there are many options of versatility with this and having access to thousands of adapters and converters, there is never a question asked in Technology in which the answer is "it cannot be done". Yes it can darn it, and I will always find a way! ;)

gkreidl
Posts: 5953
Joined: Thu Jan 26, 2012 1:07 pm
Location: Germany

Re: Comparing SD Cards - Benchmarked

Tue Feb 28, 2017 3:53 pm

For more than 4 years we have a great tutorial online here (recently updated) explaining how to move your file system to an USB drive
viewtopic.php?f=29&t=44177

Speed improvement is great, especially with jobs like compiling large projects. Throughput is between 26 and 29 MB/sec.

All my RPis run from HDD. SD cards are only used for the boot partition. Altogether I have about 8 TB of disk space connected to them.
Minimal Kiosk Browser (kweb)
Slim, fast webkit browser with support for audio+video+playlists+youtube+pdf+download
Optional fullscreen kiosk mode and command interface for embedded applications
Includes omxplayerGUI, an X front end for omxplayer

neurotico
Posts: 5
Joined: Mon Feb 27, 2017 1:37 pm

Re: Comparing SD Cards - Benchmarked

Tue Feb 28, 2017 4:45 pm

gkreidl wrote:For more than 4 years we have a great tutorial online here (recently updated) explaining how to move your file system to an USB drive
viewtopic.php?f=29&t=44177

Speed improvement is great, especially with jobs like compiling large projects. Throughput is between 26 and 29 MB/sec.

All my RPis run from HDD. SD cards are only used for the boot partition. Altogether I have about 8 TB of disk space connected to them.
Ah! Thanks gkreidl! So that article comes close...but still is offloading only the filesystem...not the OS. It is not booting from the external disk/drive and so it is not only slowing operations in throughput, but also consuming another port.

In that article, there is a link to another article which discusses booting from the external disk/drive and not needing the micro sd card at all! :D
Here is that link for reference: https://github.com/raspberrypi/document ... des/msd.md

The older method (in the link you provided), is still limiting performance considering the approach is still booting from the micro sd card and passing all filesystem data to the external disk/drive. That is consuming that micro sd slot, but also you use a USB port to have the file system on that separate device. Slower speeds & more expense & more used ports. :o
Unless the purpose is to have as much storage as possible irregardless of performance or cost. But the purpose of this article is about achieving the highest performance in boot/reboot.

The newer method in this link above, sounds like exactly what we are after! :) It claims to boot from the external device, not utilizing the micro sd slot, which makes it available for other things. Things that come to mind are obviously more storage, but how about 3g/4g service or perhaps GPS or gyroscope...thinking quad here :?: :roll: Or even use an adapter to plugin another external drive. Definitely my next endeavor with my RasPi3! :lol: :lol:

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