diff --git a/sources/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md b/sources/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md deleted file mode 100644 index 6eb0617afa..0000000000 --- a/sources/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md +++ /dev/null @@ -1,140 +0,0 @@ -(translated by runningwater) -Test read/write speed of usb and ssd drives with dd command on Linux -================================================================================ -### Drive speed ### - -The speed of a drive is measured in terms of how much data it can read or write in unit time. The dd command is a simple command line tool that can be used to read and write arbitrary blocks of data to a drive and measure the speed at which the data transfer took place. - -In this post we shall use the dd command to test and read and write speed of usb and ssd drives using the dd command. - -The data transfer speed does not depend solely on the drive, but also on the interface it is connected to. For example a usb 2.0 port has a maximum operational speed limit of 35 Mbytes/s, so even if you were to plug a high speed usb 3 pen drive into a usb 2 port, the speed would be capped to the lower limit. - -The same applies to SSD. SSD connect via SATA ports which have different versions. Sata 2.0 has a maximum theoretical speed limit of 3Gbits/s which is roughly 375 Mbytes/s. Whereas Sata 3.0 supports twice that speed. - -### Test Method ### - -Mount the drive and navigate into it from the terminal. Then use the dd command to first write a file using fixed sized blocks. Then read the same file out using the same block site. - -The general syntax of the dd command looks like this - - dd if=path/to/input_file of=/path/to/output_file bs=block_size count=number_of_blocks - -When writing to the drive, we simply read from /dev/zero which is a source of infinite useless bytes. And when read from the drive, we read the file written earlier and send it to /dev/null which is nowhere. In the whole process, dd keeps track of the speed with which the transfer takes place and reports it. - -### SSD ### - -The SSD that we are using is a "Samsung Evo 120GB" ssd. It is a beginner level ssd that comes within a decent budget and is also my first SSD. It is also one of the best performing ssds, in the market. - -In this test the ssd is connected to a sata 2.0 port. - -#### Write speed #### - -Lets first write to the ssd - - $ dd if=/dev/zero of=./largefile bs=1M count=1024 - 1024+0 records in - 1024+0 records out - 1073741824 bytes (1.1 GB) copied, 4.82364 s, 223 MB/s - -Block size is actually quite large. You can try with smaller sizes like 64k or even 4k. - -#### Read speed #### - -Now read back the same file. However, first clear the memory cache to ensure that the file is actually read from drive. - -Run the following command to clear the memory cache - - $ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" - -Now read the file - - $ dd if=./largefile of=/dev/null bs=4k - 165118+0 records in - 165118+0 records out - 676323328 bytes (676 MB) copied, 3.0114 s, 225 MB/s - -The Arch Linux wiki has a page full of information about the read/write speed of various SSDs from different vendors like Intel, Samsung, Sandisk etc. Check it out at the following url. - -[https://wiki.archlinux.org/index.php/SSD_Benchmarking][1] - -### USB ### - -In this test we shall measure the read and write speed of ordinary usb/pen drives. The drives are plugged to standard usb 2 ports. The first one is a sony 4gb usb drive and the second is a strontium 16gb drive. - -First plug the drive into the port and mount it, so that it is readable. Then navigate into the mount directory from the command line. - -#### Sony 4GB - Write #### - -In this test, the dd command is used to write 10,000 chunks of 8 Kbyte each to a single file on the drive. - - # dd if=/dev/zero of=./largefile bs=8k count=10000 - 10000+0 records in - 10000+0 records out - 81920000 bytes (82 MB) copied, 11.0626 s, 7.4 MB/s - -So the write speed is around 7.5 MBytes/s. This is a low figure. - -#### Sony 4GB - Read #### - -The same file is read back to test the read speed. Run the following command to clear the memory cache - - $ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" - -Now read the file using the dd command - - # dd if=./largefile of=/dev/null bs=8k - 8000+0 records in - 8000+0 records out - 65536000 bytes (66 MB) copied, 2.65218 s, 24.7 MB/s - -The read speed comes out around 25 Mbytes/s which is a more or less the standard for cheap usb drives. - -> USB 2.0 has a theoretical maximum signaling rate of 480 Mbits/s or 60 Mbytes/s. However due to various constraints the maximum throughput is restricted to around 280 Mbit/s or 35 Mbytes/s. Beyond this the actual speed achieved depends on the quality of the pen drives and other factors too. - -And the above usb drive was plugged inside a USB 2.0 port and it achieved a read speed of 24.7 Mbytes/s which is not very bad. But the write speed lags much behind - -Now lets do the same test with a Strontium 16gb drive. Strontium is another very cheapy brand, although usb drives are reliable. - -#### Strontium 16gb write speed #### - - # dd if=/dev/zero of=./largefile bs=64k count=1000 - 1000+0 records in - 1000+0 records out - 65536000 bytes (66 MB) copied, 8.3834 s, 7.8 MB/s - -Strontium 16gb read speed - - # sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" - - # dd if=./largefile of=/dev/null bs=8k - 8000+0 records in - 8000+0 records out - 65536000 bytes (66 MB) copied, 2.90366 s, 22.6 MB/s - -The read speed is lower than the Sony drive. - -### Resources ### - -- [http://en.wikipedia.org/wiki/USB][2] -- [https://wiki.archlinux.org/index.php/SSD_Benchmarking][1] - ----------- - -![](http://0.gravatar.com/avatar/e23f2767e6907e798da5b28694a2bf28?s=64&d=&r=G) - -About Silver Moon - -Php developer, blogger and Linux enthusiast. He can be reached at [m00n.silv3r@gmail.com][e]. Or find him on [Google+][g] - --------------------------------------------------------------------------------- - -via: http://www.binarytides.com/linux-test-drive-speed/ - -译者：[runningwater](https://github.com/runningwater) 校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 - -[1]:http://wiki.archlinux.org/index.php/SSD_Benchmarking -[2]:http://en.wikipedia.org/wiki/USB -[e]:m00n.silv3r@gmail.com -[g]:http://plus.google.com/117145272367995638274/posts \ No newline at end of file diff --git a/translated/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md b/translated/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md index 7025b9c2c5..dc1b7c3101 100644 --- a/translated/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md +++ b/translated/tech/20140714 Test read or write speed of usb and ssd drives with dd command on Linux.md @@ -12,96 +12,96 @@ Linux系统中使用 DD 命令测试 USB 和 SSD 硬盘的读写速度 ### 测试方法 ### -Mount the drive and navigate into it from the terminal. Then use the dd command to first write a file using fixed sized blocks. Then read the same file out using the same block site. +挂载上驱动盘，终端上进入此盘目录下。然后使用 DD 命令，首先写入固定大小块的一个文件，接着读取这个文件。 -The general syntax of the dd command looks like this +DD 命令通用语法格式如下： dd if=path/to/input_file of=/path/to/output_file bs=block_size count=number_of_blocks -When writing to the drive, we simply read from /dev/zero which is a source of infinite useless bytes. And when read from the drive, we read the file written earlier and send it to /dev/null which is nowhere. In the whole process, dd keeps track of the speed with which the transfer takes place and reports it. +当写入到驱动盘的时候，我们简单的从无穷无用字节的源 /dev/zero 读取，当从驱动盘读取的时候，我们读取的是刚才的文件，并把输出结果发送到无用的 /dev/null。在整个操作过程中， DD 命令会跟踪数据传输的速度并且报告出结果。 -### SSD ### +### 固态硬盘 ### -The SSD that we are using is a "Samsung Evo 120GB" ssd. It is a beginner level ssd that comes within a decent budget and is also my first SSD. It is also one of the best performing ssds, in the market. +我们使用的是一块“三星 Evo 120G” 的固态硬盘。它性价比很高，很适合刚开始用固态硬盘的用户，也是我的第一块固态硬盘，并且在市场上表现的也非常不错。 -In this test the ssd is connected to a sata 2.0 port. +这次实验中，我们把硬盘接在 SATA 2.0 端口上。 -#### Write speed #### +#### 写入速度 #### -Lets first write to the ssd +首先让我们写入固态硬盘 $ dd if=/dev/zero of=./largefile bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.82364 s, 223 MB/s -Block size is actually quite large. You can try with smaller sizes like 64k or even 4k. +的大小实际上是相当大的。你可以尝试用更小的尺寸如 64 K甚至是 4K 的。 -#### Read speed #### +#### 读取速度 #### -Now read back the same file. However, first clear the memory cache to ensure that the file is actually read from drive. +现在读回这个文件。但是，得首先清除内存的缓存，以确保这个文件确实是从驱动盘读取的。 -Run the following command to clear the memory cache +运行下面的命令来清除内存缓存 $ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" -Now read the file +现在读取此文件 $ dd if=./largefile of=/dev/null bs=4k 165118+0 records in 165118+0 records out 676323328 bytes (676 MB) copied, 3.0114 s, 225 MB/s -The Arch Linux wiki has a page full of information about the read/write speed of various SSDs from different vendors like Intel, Samsung, Sandisk etc. Check it out at the following url. +在 Arch Linux 的维基页上有一整页的关于从同的厂商，如英特尔、三星、Sandisk 等提供的各类固态硬盘的读/写速度的信息。点击如下的 url 可得到得到想着信息。 [https://wiki.archlinux.org/index.php/SSD_Benchmarking][1] ### USB ### -In this test we shall measure the read and write speed of ordinary usb/pen drives. The drives are plugged to standard usb 2 ports. The first one is a sony 4gb usb drive and the second is a strontium 16gb drive. +此次实验我们会测量普通的 USB/随身笔的读写速度。驱动盘都是接入标准的 USB 2.0 端口的。首先用的是一个 4GB 大小的 sony USB 驱动盘，随后用的是一个 16GB 大小的 strontium 驱动盘。 -First plug the drive into the port and mount it, so that it is readable. Then navigate into the mount directory from the command line. +首先把驱动盘插入端口，并挂载上，使其可读的。然后从命令行下面进入挂载的文件目录下。 -#### Sony 4GB - Write #### +#### Sony 4GB - 写入 #### -In this test, the dd command is used to write 10,000 chunks of 8 Kbyte each to a single file on the drive. +这个实验中，用 DD 命令向驱动盘写入一个有 10000 块，每块 8K 字节的文件。 # dd if=/dev/zero of=./largefile bs=8k count=10000 10000+0 records in 10000+0 records out 81920000 bytes (82 MB) copied, 11.0626 s, 7.4 MB/s -So the write speed is around 7.5 MBytes/s. This is a low figure. +因此，写入速度约为7.5兆字节/秒。这是一个很低的数字。 -#### Sony 4GB - Read #### +#### Sony 4GB - 读取 #### -The same file is read back to test the read speed. Run the following command to clear the memory cache +把相同的文件读取回来，测试速度。首先运行如下命令清除内存缓存 $ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" -Now read the file using the dd command +现在就可以使用 DD 命令来读取文件了 # dd if=./largefile of=/dev/null bs=8k 8000+0 records in 8000+0 records out 65536000 bytes (66 MB) copied, 2.65218 s, 24.7 MB/s -The read speed comes out around 25 Mbytes/s which is a more or less the standard for cheap usb drives. +读取速度出来大约是25兆字节/秒，这大致跟廉价 USB 驱动盘的标准相匹配吧。 -> USB 2.0 has a theoretical maximum signaling rate of 480 Mbits/s or 60 Mbytes/s. However due to various constraints the maximum throughput is restricted to around 280 Mbit/s or 35 Mbytes/s. Beyond this the actual speed achieved depends on the quality of the pen drives and other factors too. +> USB2.0 理论上最大信号传输速率为480兆比特/秒，最小为60兆字节/秒。然而，由于各种限制实际传输速率大约280兆比特/秒和35兆字节/秒之间。除了这个，实际的速度还取决于驱动盘本身的质量好坏以及其他的因素。 -And the above usb drive was plugged inside a USB 2.0 port and it achieved a read speed of 24.7 Mbytes/s which is not very bad. But the write speed lags much behind +上面实验中， USB 驱动盘插入USB 2.0 端口，读取的速度达到了 24.7兆字节/秒，这是很不错的读速度。但写入速度就不敢恭维了。 -Now lets do the same test with a Strontium 16gb drive. Strontium is another very cheapy brand, although usb drives are reliable. +下面让我们用 Strontium 的 16GB 的驱动盘来做相同的实验。虽然 Strontium 的 USB 驱动盘很稳定，但它也是一款很便宜的品牌。 -#### Strontium 16gb write speed #### +#### Strontium 16gb 盘写入速度 #### # dd if=/dev/zero of=./largefile bs=64k count=1000 1000+0 records in 1000+0 records out 65536000 bytes (66 MB) copied, 8.3834 s, 7.8 MB/s -Strontium 16gb read speed +#### Strontium 16gb 盘读取速度 #### # sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" @@ -110,9 +110,9 @@ Strontium 16gb read speed 8000+0 records out 65536000 bytes (66 MB) copied, 2.90366 s, 22.6 MB/s -The read speed is lower than the Sony drive. +它的读取速度就要比 Sony 的低了。 -### Resources ### +### 参考资料 ### - [http://en.wikipedia.org/wiki/USB][2] - [https://wiki.archlinux.org/index.php/SSD_Benchmarking][1] @@ -121,9 +121,9 @@ The read speed is lower than the Sony drive. ![](http://0.gravatar.com/avatar/e23f2767e6907e798da5b28694a2bf28?s=64&d=&r=G) -About Silver Moon +关于 Silver Moon -Php developer, blogger and Linux enthusiast. He can be reached at [m00n.silv3r@gmail.com][e]. Or find him on [Google+][g] +Php 开发者, 博主 和 Linux 爱好者. 通过 [m00n.silv3r@gmail.com][e] 或者 [Google+][g] 可联系到他。 --------------------------------------------------------------------------------