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diff --git a/src/Benchmarks:WD_Elements.adoc b/src/Benchmarks:WD_Elements.adoc new file mode 100644 index 0000000..ac3b128 --- /dev/null +++ b/src/Benchmarks:WD_Elements.adoc @@ -0,0 +1,115 @@ +Benchmarks:WD Elements +====================== +:author: Aaron Ball +:email: nullspoon@iohq.net + +== Benchmarks:WD Elements + +For my work computer, I installed https://archlinux.org[Arch Linux] on an +external USB hard drive. My idea behind that is that if I'm ever working from +home and forget to bring my charger with me, I can just plug the drive into +another computer and I'm back up and running. So far it's worked great. A few +months back though, I dropped the drive while it was running and while it was +surprisingly okay (despite being read-only until reboot), it was a bit slower. +I would assume a head crash, but thus far I have noticed no data corruption. + +All that said, I want to get another drive that I can mirror with (software +raid 1 anybody?), just in case something happens. I've been hunting around +online for the last few days and have found it to be impressively difficult to +find real specs on external USB hard drives. Sure, you can get that it's USB3 +and maybe even its rpm, but you're almost guaranteed not to find cache size or +even what drive is inside the enclosure, metrics I consider to be very +important. That's why I've decided to post the IO metrics for this drive. +Hopefully someone will find these metrics useful. + +image:files/WD_Elements.jpg[height=300] + +* *Manufacturer*: http://www.wdc.com/en/[Western Digital] +* *Name*: Elements +* *Made in*: Malaysia +* *Size*: 1TB +* *Interface*: USB 3.0/2.0 +* *Average Write Speed*: 104 MB/s +* *Average Read Speed*: 107 MB/s + + +[[benchmarks]] +=== Benchmarks + +[[usb3-devzero-write]] +==== USB3 /dev/zero Write + +The fastest place I can think of to get data from and avoid any bottlenecks +outside of the drive is to write from /dev/zero. The amount of processing power +that goes into writing all zeros __is insignificant next to the power of the +force__...er...reading data from another drive, potentially introducing more +bottlenecks and not getting good measurements. Let us begin... + +---- +dd if=/dev/zero of=/dev/sdc bs=1M count=8192 +8191+1 records in +8191+1 records out +8589131776 bytes (8.6 GB) copied, 82.9999 s, 103 MB/s +---- + +Double the amount of data being written... + +---- +dd if=/dev/zero of=/dev/sdc bs=1M count=16384 +16384+0 records in +16384+0 records out +17179869184 bytes (17 GB) copied, 161.13 s, 107 MB/s +---- + +Looks like overall this drive consistently averages just over 100 MB/s plugged +in to USB3. + + +[[usb3-read-to-devnull]] +==== USB3 Read to /dev/null + +Here we're basically doing the same as writing from /dev/zero, but instead +we're reading verbatim the first _x_ consecutive number of bytes and sending +them to a device that literally can't be a bottleneck: /dev/null. It's like +sending dead satellites floating into space +(https://www.youtube.com/watch?v=rWVGupqvCL8[spaaaaacce]) instead of spending +the time to land them (if they don't burn up) and disassembling. If I had to +pick somewhere to send something fast where there wouldn't be any bottlenecks, +the vast void of space is where I'd send it - that is equivelant to /dev/null. +Not a great analogy, I know, but honestly, I just wanted to reference +https://www.youtube.com/watch?v=rWVGupqvCL8[that Portal] video. + +---- +dd if=/dev/sdc of=/dev/null bs=1M count=8192 +8192+0 records in +8192+0 records out +8589934592 bytes (8.6 GB) copied, 80.5907 s, 107 MB/s +---- + + +[[conclusion]] +=== Conclusion + +* **Average write speed**: 104 MBps (832 Mbps = .832 Gbps) +* **Average read speed**: 107 MBps (856 Mbps = .856 Gbps) + +Overall I'd say this drive is okay. As mentioned, the maximum speed of the +https://en.wikipedia.org/wiki/USB_3.0[USB3 spec] is 5 Gbps and this is getting +just shy of 1/5 that. I won't balk at that because a 100 megabytes per second +transfer rate is still pretty impressive for an external hard drive (that's +838,860,800 bits per second!). + +One final thing to note, I ran these benchmarks on two systems, my laptop and +my server, to make sure the USB3 port, processor, bus, etc. weren't themselves +bottlenecks. The transfer rates were nearly identical (insignificantly +different). + + +Category:Western_Digital + +Category:Hard_Drives + +Category:Benchmarks + + +// vim: set syntax=asciidoc: |