Extending My Old iMac’s life 令我的舊iMac回復青春

My first Apple iMac has been running for more than 6 years and is still doing its very best to support my day-to-day works. To be honest, 6 years is a very long time for the life of a computer and my iMac starts to show its deficiency – start up very slowly and unable to handle those resources intensive works like multimedia editing and program development.

I have once considered to let my iMac has an early retirement and get a more powerful 27-inch iMac. However, for a retired person with no income like me, it is extremely difficult to justify the high equipment cost. As such, I have to look for other upgrade alternates for my old iMac.

My desktop is Mid-2011 iMac with 4 GB main memory, 1 TB hard disk and NO high-speed USB 3.0 support. Few years ago, I upgraded my iMac’s memory to 12 GB. In addition, I also bought a Kanex Thunderbolt adapter to provide high-speed USB 3.0 and eSATA support. The USB 3.0 adapter is being used by my 5 TB external hard disk and the eSATA is currently idle.

不經不覺中，我的第一部 Apple iMac 桌上電腦已替我工作了六年多。日常工作它仍然升任，不會令你失望，只是歳月留痕，令它慢慢的追不上時代的步伐，每次起動都需要花上十數分鐘。另一方面，我的一些視頻編輯及程式的開發工作更令它吃不消。

曾經想過叫它提早退休，再添置另一部更快的 27 吋 iMac。可是新機最小也要花上萬多元，以一個沒有工作的人來說，真有點過份。只好考慮其他的硬件升級方案，以延續它的壽命。

我的 iMac 是 2011 中期的型號，內置 4 GB 記憶體及 1 TB 硬碟，不支援較高速的 USB 3.0。好幾年前已把記憶體升級至 12 GB，並加裝了一個同時支援 USB3.0 及 eSATA 接頭的 Kanex Thunderbolt 轉接器。USB 3.0 用於大容量的 5 TB 外置硬碟，剩下那 eSATA 接頭仍然閒著。

Kanex Thunderbolt to eSATA + USB 3.0 Adapter

The objective of my planned upgrade is to shorten the processing time of my iMac in supporting those resources intensive multimedia editing software like iMovie, Photoshop and system infrastructure software like VirtualBox and Docker. My target is to achieve the best overall performance with the lowest upgrade cost. Furthermore, those new hardware equipment bought for the upgrade should also be reusable (whenever possible), in case I luckily get a new iMac in the near future.

One more point to note is that my upgrade solution will not help in those CPU bound processing as the iMac processor has not been upgraded.

今次升級主要是針對 iMac 處理時間的提升，以應付一些需要較多資源的多媒體編輯軟件如 iMovie，Photoshop 及一些系統基建的軟件如 VirtualBox，Docker 等。目標是以較低的價錢而改善整體的運行速度。另一方面，即使日後可能會添置新一代的 iMac，也希望今次新購買的硬體亦可重用，以減少浪費。

由於今次的升級方不涉及中央處理器的轉換，對一些需要大量處理器運算的工作，應該是沒有甚麼幫助。

---

Upgrade Solution  升級方案

With those considerations in mind, I have worked out the following upgrade solution:

1. Increase main memory to 24 GB – iMac comes with four memory slots. Mine is running with two 2 GB and two 4 GB memory modules. Despite official specification only accepts highest capacity memory module of 4 GB, the actual highest support module size is 8 GB. Since iMac 8 GB DDR3 SODIMM memory module is still a hot item in the replacement market and comes with a high price tag, I have adopted a more cost-effective configuration by only replacing the two 2 GB modules with two 8 GB modules.
2. Install external SSD and transfer OS X boot disk from the internal hard disk to the SSD – The slow system startup and long multimedia editing time are mainly limited by the physical characteristic of the internal hard disk. SSD will be used to speed up those physical disk read/write operations and improve the disk storage response time. There are a number of approaches:
   1. Replace the internal hard disk with SSD
   2. Install SSD using the built-in second internal SATA interface (currently idle)
   3. Connect external SSD via built-in high-speed interfaces, eg. Thunderbolt

The first two methods require removal of the iMac screen, internal components and cables which are quite complicated and prone to error. As my Kanex Thunderbolt adapter has an idle eSATA interface that supports 6 Gbps SATA devices, I will follow the third approach and connect an external SSD via the Thunderbolt/eSATA interface.

幾經思量，最後確定了以下升級方案：

1. 記憶體增加至 24 GB – iMac主機提供四條記憶體槽，而我的 iMac 是由兩條 2 GB 及兩條 4 GB 記憶模組所組成。雖然 2011 年記憶模組的官方上限是 4 GB，但實際每條槽均可支援最大 8 GB 的模組。由於現時8 GB DDR3 SODIMM 在升級市場仍然熱賣，模組價錢頗高，我作了一個更高性價比的選擇，只把兩條 2 GB 模組換成 8 GB 模組。
2. 安裝外置 SSD 並把 OS X 系統 boot disk 搬至 SSD – 漫長的系統起動及緩慢的多媒體編輯工作主要是受限於硬碟的物理特性，為了提高儲存裝置的讀寫反應，會用 SSD 代替硬碟。方法有以下幾種：
   1. 直接更換內置硬碟
   2. 安裝附加 SSD 於內置第二 SATA 介面(閒置)
   3. 利用高速介面，安裝外置 SSD

前兩種方法需要拆除 iMac 顯示屏冪、零件及接駁線，步驟頗為煩複，亦容易出錯。由於我的 Thunderbolt 轉接器有提供 eSATA 插口，並且支援 6 Gbps SATA SSD 裝置，所以我會選用第三種方法。透過外置 eSATA儲存盒來接駁 SSD。

Hardware for field upgrade 購置的升級硬件

Currently, all of the external disk enclosures available in Hong Kong only provide USB 3.x or Type-C interfaces. As such, I have to get my eSATA external disk enclosure via Amazon US. Ordering was simple and the item was shipped to Hong Kong in 8 days.

現時在香港售賣的外置儲存盒只提供 USB3.x 或 TYPE-C 接口，因此我只好在 Amazon US 訂購所需的 eSATA 外置儲存盒。手續簡便，貨品八天內送抵香港。

---

Preparation  事前準備

Memory installation is straight forward and no preparation is required. On the other hand, transferring the existing system boot disk to the external SSD requires quite a lot of planning works.

My iMac comes with built-in 1 TB hard disk and I only have less than 100 GB of free storage. Since I have bought a 512 GB SSD, I have to move or clean up at least 500 GB of data from my existing boot disk.

Notice that basic configuration for some selected iMac or Macbook Pro models only come with 256 GB SSD. This implies that 256 GB should be sufficient to run the OS X System, other data can be moved to external storage without any issues.

I take the following approach for the storage relocation and housekeeping works:

1. Backup the internal hard disk (OS X boot disk) with Apple Time Machine

2. Relocate those big folders to my 5 TB external disk storage, eg.:

• Documents – Personal files, approximately 45 GB.
• Movies – iMovie database (imovielibrary*), approximately 140 GB.
• Music – iTunes folder, approximately 35 GB.
• Pictures – Photos (or iPhotos) database (Photo Library 2.photoslibrary), approximately 180 GB. I had switched to Lightroom for photo management years ago and the mentioned Photos databases contained all my old photos.
• VirtualBox VMs – I’m using VirtualBox to setup virtual machines for running Windows and Debian Linux. Those virtual system images occupied approximately 170 GB.

3. Housekeep obsolete hard disk data:

• Mails – Obsolete email, approximately 500 MB.
• Google Drive / iCloud Drive – Files in Cloud storages but synchronised to local hard disk, approximately 8 GB.
• iOS Files – iPhone/iPad’s backup images, iOS installer files, approximately 130 GB.

It is hard to imagine that I have got so much “rubbish” residing on my system boot disk!

With patience and great efforts, I managed to reduce the system boot disk size down to around 294 GB, ready for copying to the SSD.

4. Run Apple Time Machine again to backup the “housekept” system boot disk again for the subsequent SSD boot disk rebuild.

記憶體升級工序直接簡單，不需特別安排，但是把系統硬碟轉換至外置 SSD 就要花多點心思了。

我的 iMac 內置 1 TB 硬碟，升級前已餘下不足 100 GB 的空間。而新購置的 SSD 則只 有512 GB，換句話說，我需要清理最小 500 GB 的儲存資料。

如果有留意一些 iMac 或 MacBook Pro 的基本配置，內置的 SSD 都只有 256 GB。這証明 256 GB 已足夠系統運作，其餘的資料應可搬到外置的儲存裝置。

我的做法是:

1. 利用 Apple Time Machine 先把舊系統硬碟備份

2. 把大容量的文件庫搬到我的 5 TB 外置的硬碟。例如：

• Documents – 個人檔案，約 45 GB。
• Movies – iMovies 的資料庫 (imovielibrary*)，約 140 GB。
• Music – iTunes 的文件庫，約 35 GB。
• Pictures – Photos (或 iPhotos) 的資料庫 (Photo Library 2.photoslibrary)，約 180 GB.。我早已轉用 Lightroom 作相片的資料庫，這個 Photos 的舊資料庫儲存的全是舊相片。
• VirtualBox VMs – 我有利用 VirtualBox 建立虛擬機器來運作 Windows 及 Debian Linux，系統檔案約 170 GB。

3. 清理過時的硬碟資料：

• Mails – 過時的電郵，約 500 MB。
• Google Drive / iCloud Drive – 同步在硬碟上的雲端檔䅁，約 8 GB。
• iOS Files – iPhone/iPad 的舊備份檔案、升級用的安裝檔案，約130 GB 。

很難想像原來我的系統硬碟有這麼多”垃圾“！

經過一番努力，我最後把硬碟的用量減至約 294 GB，可以複製到 SSD 了。

4. 再利用 Apple Time Machine 為準備好的舊硬碟備份，用作建立升級後的 SSD 系統。

By the way, it is a good practice to regularly monitor and clean up the system boot disk using the following steps:

大家平常可用以下的方法去監察及清理你的系統硬碟：

About This Mac → Storage → Manage (Macintosh HD)

---

Hardware Upgrade  硬件升級

It only takes 5 minutes to carry out the main memory replacement/upgrade. You may refer to the procedure available in Apple’s support website.

Installation of external SSD is also a simple task. Just connect the IDsonix external storage enclosure to the Kanex Thunderbolt adapter (eSATA interface is on the right in the following image) using eSATA cable. Power on the external storage enclosure followed by power on of the iMac.

主記憶體的更換、升級，只需 5 分鐘，大家可以參考這個官方連結。

外置 SSD 的安裝亦很容易，主要是利用 eSATA 數據線把 IDsonix 外置儲存盒連接在 Kanex Thunderbolt 轉接器上 (下圖右邊插座)。先開啟儲存盒的電源，再起動 iMac 即可。

IDsonix eSATA External disk enclosure/SSD installation  外置儲存盒及SSD連接

---

System Reconfiguration  系統配置

Power on the iMac after memory and SSD installation. Verify the hardware status.

安裝好記憶體及 SSD 後，重新起動 iMac。檢查新的硬件狀況。

Memory configuration  記憶體配置

External SSD configuration  外置SSD配置

Noticed that the ADATA SSD supports 6 Gbps transfer speed (Negotiated Link Speed: 6 Gigabit), higher than the original built-in 1TB hard disk (3 Gbps).

Use the following procedure to rebuild the OS X boot disk onto the SSD:

1. Run “Disk Utility” to create a Partition on the SSD. You may use the same partition name “Macintosh HD“. Format must be “Mac OS Extended (Journaled)” and Partition Scheme is “GUID Partition Table“.

2. Restart iMac. Press “Command-R” during the restart and the “OS X Recovery Partition” will be started.

3. Click on “Restore from Time Machine Backup“.

4. Select the Time Machine Backup images that previously created in the last step of the preparation. Target disk of restore is the newly installed SSD.

5. After the “Restore” processing was completed, restart iMac.

Congratulations, all the upgrade works were completed and you are ready to verify the final system configuration.

留意新的 ADATA SSD 支援 6 Gbps 的傳輸速度 (Negotiated Link Speed: 6 Gigabit)，比內置的 1 TB 硬碟 (3 Gbps) 更高速。

接著用以下步驟去重新建立 OS X 系統於 SSD 上：

1. 利用 Disk Utility 為 SSD 建立一個 Partition。名稱可用回 “Macintosh HD“，格式必須是 “Mac OS Extended (Journaled)“。Partition Scheme 是 “GUID Partition Table“。

2. 重新起動 iMac 及按著 “Command-R“，系統會啟動 “OS X Recovery Partition“。

3. 選擇 “Restore from Time Machine Backup“。

4. 揀選先前在 “事前準備” 一節內最後製作的備份，目標硬碟是新安裝的 SSD。

5. 當 “Restore” 完成後，重新起動 iMac。

好，一切的升級工序已完成，先來確認最後的系統配置。

Upgraded iMac System Configuration  升級後的 iMac 系統配置

From my previously attached screen capture of the ADATA SU800 SSD configuration, you may find that TRIM support is not enabled in the latest Mac OS X High Sierra (TRIM Support: No) for my SSD. This is not the same for the latest Macbook Pro which also runs High Sierra. I believed that since Apple has no way to ensure all the third-party SSD devices have TRIM support, they just leave the option as disabled for all non-Apple SSD devices.

According to product information available in the ADATA official website, SU800 SSD is equipped with TRIM support. I will manually turn on TRIM support with the “trimforce” command after my upgraded iMac has been running successfully for a while.

如果大家有留意先前貼上的 ADATA SU800 SSD 配置，會發覺 TRIM 在最新的 Mac OS X High Sierra 上是沒有被啟動 (TRIM Support: No)，這與同樣運行 High Sierra 的 Macbook Pro 不同，相信這是因為 Apple 沒法肯定第三方的 SSD 是否支援 TRIM。

根據 ADATA 官方網頁的資料，SU800 SSD 是有提供 Trim 的支援。我會待升級了的 iMac 正常運作一段時間後，便會自行把 TRIM 支援經 “trimforce” 指令啟動。

---

Conclusion  總結

After spending more than a week’s time, working day and night in upgrading this “old dog”, what are the results?

花了個多星期的時間，捱更抵夜為這隻 “老狗” 升級，成効如何呢？

Let’s take a look at the performance benchmark:

先來看看効能的提升：

Test Items   測試項目	Before Upgrade   升級前	After Upgrade   升級後
iMac Power up until logon screen is displayed 開機至登入畫面	5 min	20 sec
From logon until Facebook startup 登入至開啟Fackbook網頁	3 min	2 sec
Virtualbox Windows 10 startup until ready for logon 起動VirtualBox內Windows 10虛擬系統至登入	17 min	42 sec
iMovie startup 起動iMovie	3 min	5 sec
Lightroom startup 起動Lightroom	5 min	6 sec

And the associated upgrade cost:

再計算升級之費用：

Hardware Item   硬體項目	Upgrade Cost (HKD)   價格 (HKD)
16 GB RAM Upgrade 記憶體	1,160
IDsonix eSATA External Disk Enclosure 外置eSATA儲存盒	216
ADATA SU800 512GB SSD	1,340
Total Cost 總計	2,716

Is this iMac upgrade solution a cost-effective one? I will leave it to the readers to comment.

這個升級方案，究竟是否物有所值呢？就留待大家去決定了。