机械硬盘与固态硬盘

机械硬盘与固态硬盘 仅因更快更安全,商用本缘何青睐SSD 来源:中关村在线 作者:胡杨 时间:2012-9-27 08:57 关键字: 硬盘 的 局限性 机械硬盘成本低，但机械硬盘也有一定的问题。提升机械硬盘的读写速度一般而言有两个办法。一是提升磁介质的存储密度，二是提高马达的转速。但是基于现在的技术，已经接近了物理的瓶颈，同时提高这两个技术指标也有局限性。过于密集的存储密度也会增加寻道时间，同时过高的马达转速会让硬盘功耗更大而且不稳定不安全因素也更高。因此固态硬盘相对传统的机械硬盘还是有很多的优势，也成为了商用笔 记本等高端领域的首选。 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 首先我们也把目前传统的对固态硬盘的优势和劣势都罗列出来，然后我们还会分析其中的观点，这些 优势和劣势并不一定是完全正确的，我们留到后面讨论。 固态硬盘优势 1、启动快，没有电机加速旋转的过程; 2、不用磁头，快速随机读取，读延迟极小; 3、相对固定的读取速度，由于寻址时间与数据存储位置无关，因此磁盘碎片不会影响读取时间; 4、写入速度快(基于DRAM)，硬盘的I/O操作性能佳，能够明显提高需要频繁读写的系统的性能; 5、无噪音; 6、低容量的基于闪存的固态硬盘在工作状态下能耗与发热量较小，但高端或大容量产品能耗较高; 7、出现机械错误的可能性很低，不怕碰撞、冲击和震动; 8、工作温度范围大; 9、体积小 固态硬盘优势明显 固态硬盘劣势 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 1、成本高、最大容量低;这个很容易理解了，目前固态硬盘用户并没有机械硬盘普及，这也反促价格 居高不下。 2、由于不像传统硬盘那样疲敝于法拉第笼中，固态硬盘更容易收到某些外界因素的不良影响。如断电 (基于DRAM的固态硬盘尤甚)、磁场干扰、静电等。 3、写入寿命有限(基于闪存)。一般闪存写入寿命为1万到10万次，特制的可大100万到500万次， 然而整台计算机寿命期内文件系统的某些部分的写入次数仍将超过这一极限; 4、数据损坏后难以恢复。一旦在硬件上发生损坏，如果是传统的磁盘或者磁带存储方式，通过数据恢复也许还能挽救一部分数据。但是如果是固态存储，一但芯片发生损坏，要想在碎成几瓣或者被电流击穿 的芯片中找回数据那几乎就是不可能的。 传统机械硬盘和固态硬盘比较 以上的观点并不完全正确，也有值得商量的地方。比如固态硬盘的数据恢复和寿命问题就值得一谈。SSD使用寿命真低吗 P/E指的是一次完整的写入，因为固态硬盘厂商会承诺一个最大完整写入数，这也让很多消费者认为固态硬盘的寿命会很短。多数人认为所指的一次P/E写入就是文件擦除，所以认为下载对于硬盘的读写能力损耗非常的大。其实一次完整的P/E是指产品实际容量的等量数据写入，才算消耗了产品的限制的1/3000 或1/5000，例如一块64GB的固态硬盘，要写入64GB的容量才算是一次P/E消耗。 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 固态硬盘使用寿命计算 官方标称的主控总写入寿命=盘片容量*PE数/写入放大系数，写入放大系数就是需要写入一个10GB 的高清电影的容量=硬盘实际写入了一个等于10GB的数据容量，固态硬盘与机械硬盘的最大的写入区别就 在于:必须先擦除某索引区的文件，然后在写入操作，而机械硬盘则可以直接覆盖。 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 国外进行的固态硬盘耐久测试 如此看来一块P/E最大标称值为5000的固态硬盘，平均每天写入20GB的话，用3年到5年应该没有问题。而对于5000这个数值也不是说到了5000，固态硬盘就马上损坏。国外一位资深的媒体评测人员 对多款固态硬盘进行了耐久性测试发现，即使到了最大标称数的时候，固态硬盘仍然 SSD综合安全性高 安全性其实有很多方面，有可能是物理损坏还有就是数据的逻辑损坏。机械硬盘存在读写头和盘片有可能接触的问题，因此在运行中如果突遇断电或者是震动就可能造成损坏。在这方面固态硬盘由于物理结 构上的优势，并不存在这方面的问题。 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 机械硬盘先天劣势难以提高抗震特性 因为机械硬盘具有读写头、高速转动的马达和涂有磁介质的盘片等物理结构，对环境的要求也相对较 高。如果灰尘太多、温度太极端对使用寿命都会有很大的影响，在个别情况下会停止工作。固态硬盘对环 境的要求不是太高，这也是军用级别的笔记本近年来都采用固态硬盘的缘故。 固态硬盘安全性优势明显 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 数据丢失了以后，传统机械硬盘可以进行数据恢复，大部分软件恢复的原理是计算机存储数据的原理出发。这个原理同样适用于固态硬盘，因为固态硬盘当中的文件结构和之前没有变化。但是对于物理损坏，传统机械硬盘仍然有办法进行恢复和补救，比如扫描拍照等手段，但固态硬盘如果出现物理损坏，一般而言是没办法恢复，这也是很多人说固态硬盘数据恢复是难题的原因。但从另一方面讲，即使是机械硬盘出现物理损坏有办法恢复数据，也不是100%的数据都能找回，出现的物理损坏越多恢复的难度越大，能恢 复的数据也越少。 因此综合看，固态硬盘的安全性要高于普通的机械硬盘。 面向高端用户本首选SSD 戴尔Vostro3360部分型号采用固态硬盘的设计，而面向中大型企业的Latitude全系列均能选配固态 硬盘。下面我们首先看看固态硬盘和机械硬盘在读取速度上的差别。 Vostro 3360笔记本部分机型采用固态硬盘 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 传统机械硬盘平均速度90MB左右 衰减比较严重 采用固态硬盘的V3360现突出 曲线平滑 平均292MB spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld 虽然震动撞击对固态硬盘硬盘的影响较小，但作为商用电脑V3360仍然体现出了专业商用机对数据安全的不懈追求。我们经过拆解发现，四颗螺丝将固态硬盘固定在一个铝制支架上，然后利用四颗螺丝六个固定点固定该块硬盘，同时硬盘一侧还有大块的橡胶垫保护。 V3360配置128GB固态硬盘 小结: 整体来看，固态硬盘虽然还有价格较高的劣势，但我们通过分析，它的使用寿命并不短，对工作环境要求不高，防震效果比较好，尤其是可以抵御工作中高频次的振动。同时随机读取速度远高于机械硬盘也使得它在高性能存储应用中独占鳌头，这样我们也就不难理解面向高端用户的商用笔记本为何首 spot welding, spot welding fittings mat must be placed firmly before, to avoid forced groups to arise, additional stress caused by crack. (5) the Groove position welds and welding the same welding process should be adopted, by qualified Welders and welding. Tack weld should be evenly distributed, there is generally no less than 2-3, length should be to 10-15mm, uniform distribution, wall thickness of no more than 2/3. (6) the tack should ensure good penetration and fusion, and free of porosity, slag and other defects. (7) to ensure the bottom bead molding well to reduce stress concentration, tack should be a smooth transition to the base metal and welds polished at both ends should be generated. (8) unless the process or inspection required-welded, but each seam continuous welding finish, otherwise again before welding, to preheat the weld. (9) the welding arc scraped surface is strictly prohibited, without any introduction arc welding on the surface. (10) should ensure that the arc and arc welding of quality, arc should fill crater, multi-pass welding joint should be staggered. (11) Tig welding should be ventilated in advance, expired after welding should be delayed, and should ensure that the welding in the welding process melts to get effective protection of argon gas. (12) when using the multi-pass welding, weld before should be cleaned, after making sure that no defects, and again the next. (13) the weld should be a smooth transition to the base metal and weld both ends ground into slope. (14) card with the welding, the material should be identical to the base metal, and at the time of demolition cards should not damage materials and residues in the welding scar on the base metal polished fixed flush to the base metal. (15) the finished weld, weld