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Choosing an Apple silicon Mac

This coming autumn it’ll be five years since Apple started shipping its first Apple silicon Macs, and it’s already four years since the first M1 iMac. As prices of used Intel Macs are tumbling, more Apple silicon models are coming onto the used market. With a total of 15 basic M-series chips now available, this article tries to help you decide which new or used Apple silicon model to buy.

CPU cores

With such a wide choice, this is perhaps the most complex feature to understand, and it’s likely to make the biggest difference to what your Mac will do. M-series chips have anything from 2-8 Efficiency (E) cores, and 4-24 Performance (P) cores across four different families.

Although folk are usually more concerned with the number of P cores, E cores are responsible for doing much of the routine work, and shouldn’t be ignored. They run most of the background tasks in macOS, from Time Machine backups to indexing all your images and documents for Spotlight. P cores are largely responsible for running the code in your apps, so determine how fast it feels in use.

Most M-series chips have at least 4 E cores, but two, the M1 Pro and M1 Max, have only 2. They compensate for that by running those E cores at higher frequencies when working on heavy background tasks, but subsequent designs have set the comfortable minimum at 4, and the latest base M4 comes with 6. Of the two core types, E cores are the more versatile, as they can run all types of task, background or user, and when running at their maximum frequency can deliver a high proportion of the processing power of a P core. As an E core’s energy use is much lower than that of a P core, they’re a better option when running a laptop Mac on its battery.

The four E cores in this M4 Pro are kept fully occupied in the minutes after starting up, leaving the P cores free for running apps smoothly.

P and E core performance has increased with each new family. This is illustrated in different types of computation, when running one thread on a single core.

M4M3multiTests

The Y axis here gives loop throughput per second for my four basic in-core performance tests, a tight assembly code integer math loop, another tight assembly code loop of floating point math, NEON vector processor assembly code, and a tight loop calling an Accelerate routine run in the NEON unit. Pale blue bars are results for the M1, purple for the M3, and red for the M4, the higher the bar the faster.

Maximum core frequencies have increased from 3.2 GHz in the M1’s P cores to 4.5 GHz in the M4. One crude comparative measurement of overall computing capacity is to total the maximum frequencies for each of the CPU cores in each chip. Those are shown as Σfn in the table below, and the chart that follows it.

These are also complicated by sub-variants and binned versions, where one or two cores have been disabled by Apple, to produce a cheaper chip.

If you’re looking for CPU performance, the M3 Max, and M4 Pro and Max stand out and approach the performance of Ultra chips. But those assume that the software running is able to make full use of all the cores available. There’s no point in paying for the 32 cores in an M3 Ultra if the app you run most can’t use many of them.

Another detail that’s easily overlooked is the instruction set (ISA) supported, notably that of the M4, which includes new features for accelerated matrix and other computation. In this respect, the M2 family has been underrated, as I’ve explained here.

GPU

For most, the choice of CPU cores determines the GPU provided, and for general use they’re well matched. Exceptions to this are when high GPU performance is essential, and to support external displays. In either case you’ll need to check carefully with Apple’s specifications or Mactracker to ensure support. That’s particularly important when driving multiple high-resolution displays.

Memory

Memory options are determined by the chip, with some starting at only 8 GB, which is insufficient even for the lightest use. There was a myth that the use of Unified memory would result in substantial economy in memory use, but in practice that doesn’t work out, and demand for memory has increased with the introduction of new features such as AI.

The danger with this is that using substantial amounts of swap storage is deceptively fast because of the high speed of the internal SSD. As models with 8 GB memory often have small SSDs as well, this is likely to lead to rapid ‘wear’ of the SSD, and some early adopters saw worryingly rapid changes in wear indicators. Fortunately, Apple has recognised this problem, and all M4 models now come with a minimum of 16 GB.

If you’re interested in buying an older model with only 8 GB, at least check its SSD size and wear indicators before parting with your money. Further information about memory requirements is here.

SSD

While it’s possible to enjoy using an Apple silicon Mac with only 256 GB internal SSD, unless you’re frugal in its use you’ll find yourself buying a more substantial external SSD to supplement that. You can start up an Apple silicon Mac from macOS on an external SSD (or even a hard drive, if you must), but that’s more fussy than with an Intel Mac. If you want to consider relying on external storage, this article explains how best to do that.

For most users, a minimum internal SSD requires 512 GB for comfort and a long life.

Buy to upgrade

Until recently, all Apple silicon Macs have been stuck with the CPU cores, GPU, memory and internal SSD that they came with. That may be changing with some now offering SSD upgrades for the M4 Mac mini. However, those are likely to invalidate your warranty, and aren’t likely to be available for other popular models, apart from the Mac Pro.

Recommendations

  • Prefer a later Pro or Max chip over an M1 Pro or Max, to get at least 4 E cores.
  • E cores are more versatile than P cores, and an advantage when a laptop is powered by its battery.
  • If you need to use external displays, check the model’s support for their number and resolution.
  • Look for a minimum of 16 GB of memory.
  • When buying a model with 8 GB of memory, check the wear on its SSD.
  • Prefer a minimum of 512 GB SSD to avoid relying on external storage.
  • Don’t rely on upgrading any Apple silicon Mac’s internal hardware.

Enjoy your new Mac!

个人备份指北

备份的意义

我想大家都多多少少遇到过设备死机、进水、被偷,甚至被黑客勒索的事情吧。从概率上来说,数据丢失只是早晚的事情。这就是为什么要备份,不然可能青春的回忆,各种美好就再也不见了,那会很痛,可能比失恋还痛。

「不同裝置都有相同的資料才叫作資料備份,只是換個裝置存放不叫做備份[1]

我和一些网络上厉害的家伙聊过,发现他们也没有做到真正的备份。把数据一股脑丢进硬盘,把数据丢进各种网盘/云服务,甚至程序员也只是把代码放在 GitHub 上。这些都不是备份,国内的网盘不说了,诸如 iCloud 和 Google Drive,本质是个同步盘。历史上不管是 iCloud 还是 Google Drive 都出现过宕机问题,不把鸡蛋放在一个篮子里,要狡兔三窟。

备份的目的是为了可以「无损」还原,如果不能还原,储存再多的数据也没有意义。

备份类型

  • 全部备份(Full Backup,包括系统)备份数据量大,备份所需时间长。
  • 增量备份(Incremental Backup)自上一次完全备份后有变化数据的备份
  • 差异备份 (Differential backup) 提供完整备份后变更的文件

第一种全盘备份,举个例子,从一台电脑上一模一样搬迁到另一台电脑上。有些备份是不包括系统设置数据的,还原数据后需要重新设定应用设置、字体大小、系统语言啊,种种……准备系统备份的好处在于带有一个开机系统,比如 Windows 的 WinPE,macOS 的可引导安装器

差异备份与增量备份的区别在于前者包括上一次完全备份、差异备份或增量备份,后者仅是上一次完全备份后有变化。挺绕的……

3-2-1-1-0 原则

  • 至少做三份数据副本(一份本体,两份 copy)
  • 存储在至少两种不同类型的存储介质
  • 在异地位置保留一份备份副本

在 3-2-1 原则再加两点[2]

  • 将一份媒体副本离线或隔空
  • 确保所有可恢复性解决方案没有错误(刚说备份之目的)

在这个科技高度发展的年代,其实最安全的储存方式还是用磁带保存,埋在一个角落(比如 GitHub 埋在北极的胶片[3])。

云备份

当然我们不用这么极端,用个靠谱的云备份就行了,也是一种异地备份。刚刚讲过,常规的那些网盘不算备份,要选择专门用来备份的云存储服务,那么靠谱的备份服务有哪些呢,可选的不多。

大家公认的有 Backblaze Personal Backup。每月 $7,不限备份容量,从 2007 年运营至今,稳定。懒人首选,只要后台开着软件就可以无感备份,手机端有 App 也可以备份。

对于国内用户来说由于网络封锁,需要耗费代理流量,第一次备份需要注意流量。从国内访问,稳定性一定要考虑,可是目前无解。

还有一个严格意义来说不算提供云储存服务的软件——Arq, 2009 年运营,$49.99 买断单设备,Premium $59.99/year(提供 1 TB 云空间,不推荐)

搭配第三方云端空间使用,官方描述:Use it for encrypted, versioned backups of your important files. 有加密功能不错。

相当于一个云服务整合管理器

硬盘备份

推荐用硬盘来储存,硬盘分为 HDD(机械硬盘)和 SSD(固态硬盘),硬盘可是大有学问,这里不展开了,感兴趣的可以在本 blog 搜索 SSD

相比之下 SSD 的优势在:

  1. SSD 读取写入速度快,快就是王道
  2. SSD 的寿命(写入和擦除)长
  3. SSD 可以在使用中移动

缺点:

  1. 售价贵
  2. 恢复数据困难

不管是 HDD 还是 SSD,「任何的存储装置都是消耗品」,说不定哪天就挂掉了,所以多准备一块硬盘吧。虽然 SSD 也能抢救资料,但是恢复难度大(要看硬盘哪里损坏)关键是数据恢复又贵(基本 ¥2000 以上)又麻烦还不安全(冠希哥艳照门)。

Time Machine

用 Mac 的同学可以用一下这个,免费,但是不太好用,设定逻辑太简单,Apple 没有好好做,所以有下面的软件推荐。

搭配硬盘使用的备份软件

  • SuperDuper (2004 年 $27.95 买断制,有免费版功能少一点也可以用,优点是可以把 SSD 作为一个启动盘,支持差异备份。

  • Carbon Copy Cloner 6 $39.99 更加老牌的一个软件,官方的口号是「A leader in Mac backups since 2002」,速度和稳定性比 Time Machine 好,口碑不错。

上述备份软件和 Backblaze 都提供试用,可以选择一款适合自己的。

NAS 备份

我没有使用 NAS,这方面不了解,根据需求选择。用 NAS 也要有双保险,做好异地备份。虽然硬盘不怕坏了,但是也有一些不可抗力因素。

备份内容

除了全盘备份,还需要注意保存在云上的数据,比如我存在 Bitwarden 上的密码。暂时好像没有别的了。


看了那么多,今天你备份了吗?Just do it!

参考

PrimoCache:让固态硬盘作为缓存给机械硬盘加速

对于电脑硬盘,固态肯定是全方面优于机械硬盘的选择,不过按照马克思主义矛盾论的观点,这就存在一个 “低速的 HDD 与高价的 SSD” 之间的矛盾。目前我的笔记本使用 128G+1T 的组合,处于并将长期处于 “个人电脑硬盘的基本矛盾” 之中。

直到,我遇到了 PrimoCache 这款软件。推荐给大家。

PrimoCache 是一款可以将物理内存、SSD 硬盘或闪存盘等虚拟成硬盘缓存的软件。它可以自动将硬盘中读取的数据存入物理内存等速度较快的设备,当系统再次需要该数据时它可以很快从缓存设备中读取,而无需再次访问速度较慢的硬盘,从而有效提升物理硬盘的访问性能。

中文官网:http://www.romexsoftware.com/zh-cn/primo-cache/index.html
平台:Windows(其实 *nix 下也有类似的)
软件类型:共享软件

两个月后更新:

经过 2 个月的实际体验,这款软件并没有宣传的那么完美。少数软件一运行就会完全死机(跑跑卡丁车,并确定是由该软件造成的),整个系统也似乎有一种不稳定的感觉(偶尔弹出一些意义不明的错误提示)。另外还有额外的内存占用。

总之,不推荐将系统盘加速,也不推荐大多数情况下的使用。除非你有一些常玩的游戏,但由于几十 GB 的体积巨大不能放入 SSD,才值得使用此软件。

缓存技术

这种理念我认为非常好,Cache 技术也是计算机硬件软件当中一个使用非常广泛的技术。这和最初的英特尔快速存储技术(RST)以及英特尔傲腾技术类似。都是使用少量高速的 SSD 作为缓存,为低速的 HDD 加速, 使得电脑拥有 HDD 的大容量的同时,拥有接近于 SSD 的速度。

至于什么数据会被缓存到 SDD 中?这是由算法控制的,自动选择 HDD 中最常用的那些数据。

PrimoCache 与 RST 或者傲腾的区别在于,这款软件不需要你使用最新的 Intel 主板,或者是购买 Intel 家的傲腾内存,它兼容一切现有的 SSD。

PrimoCache 还支持使用内存作为一级缓存,SSD 作为二级缓存

是的,这也是 PrimoCache 的一个特有的功能,内存的每秒读写速度单位在 GB 级别,比 SSD 高了一个量级,能有效为 SSD 加速。(不过我还没有直观感受到差异,大概在这时瓶颈已经不在 IO 了)

效果展示

我现在终于可以把动辄几十 G 的游戏放心的放在机械硬盘了,然后使用 PrimoCache 让他们拥有令人满意的读取速度。

我使用了 12G SSD 作为二级缓存,1G RAM 作为一级缓存,运行测速工具对机械硬盘测速结果如下:

未使用缓存:

使用缓存:

注意,由于缓存的原理是将常用数据放在 SSD、RAM 中,需要时快速获取,所以使用测试软件随机读取或写入时并没有预存这个过程,并不能反映实际效果。
但是我们也可以看到明显的进步了。

注意事项

发现的缺点:

  • 使用二级缓存 SSD 时,需要占用一定量的内存用于存储映射。
  • 这是一个收费软件,虽然有破解版。
  • 之前出现了一次显卡被降频,关闭该软件后恢复。但后来开启该软件又没有出现类似状态。

此外,虽然我的 RAM 有 16GB,但我也只使用了不到 2GB 作为硬盘缓存,因为我觉得目前大多数大型软件都会使用 RAM 为自己加速,我们没必要多此一举。并且充裕的 RAM 本身也是提升电脑响应速度的途径。

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