{"id":47128,"date":"2025-03-18T14:26:34","date_gmt":"2025-03-18T18:26:34","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=47128"},"modified":"2025-03-18T14:27:09","modified_gmt":"2025-03-18T18:27:09","slug":"mac-ssd-performance","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2025\/03\/18\/mac-ssd-performance\/","title":{"rendered":"Mac SSD Performance"},"content":{"rendered":"<p><a href=\"https:\/\/www.macintouch.com\/post\/46034\/ssd-issues\/\">Ric Ford<\/a>:<\/p>\n<blockquote cite=\"https:\/\/www.macintouch.com\/post\/46034\/ssd-issues\/\">\n<p>Apple&rsquo;s exhorbitantly-priced Mac storage comes with impressive benchmark claims but has some serious, hidden bottlenecks in certain scenarios, as do other SSDs.  <a href=\"https:\/\/www.youtube.com\/watch?v=NrJ36oPmXgM\">David Harry<\/a> illustrated this clearly in a video, using Activity Monitor as a novel window into dramatic SSD slowdowns when moving large amounts of data to an Apple internal SSD from a third-party Thunderbolt 5 SSD.<\/p>\n<\/blockquote>\n<p>He actually finds that the external SSD, connected via Thunderbolt 4, is faster at reading than the MacBook Pro&rsquo;s internal one. Write performance drops once the SLC cache is full.<\/p>\n\n<p><a href=\"https:\/\/eclecticlight.co\/2025\/03\/17\/why-ssds-slow-down-and-how-to-avoid-it\/\">Howard Oakley<\/a>:<\/p>\n<blockquote cite=\"https:\/\/eclecticlight.co\/2025\/03\/17\/why-ssds-slow-down-and-how-to-avoid-it\/\">\n<p>In normal use, there are three potential causes of reduced write speed in an otherwise healthy SSD:<\/p>\n<ul>\n<li>thermal throttling,<\/li>\n<li>SLC write cache depletion,<\/li>\n<li>the need for Trimming and\/or housekeeping.<\/li>\n<\/ul>\n<p>[&#8230;]<\/p>\n<p>To achieve their high storage density, almost all consumer-grade SSDs store multiple bits in each of their memory cells, and most recent products store three in Triple-Level Cell or <em>TLC.<\/em> Writing all three bits to a single cell takes longer than it would to write them to separate cells, so most TLC SSDs compensate by using caches. Almost all feature a smaller static cache of up to 16 GB, used when writing small amounts of data, and a more substantial dynamic cache borrowed from main storage cells by writing single bits to them as if they were SLC (single-level cell) rather than TLC.<\/p>\n<p>[&#8230;]<\/p>\n<p>Keep ample free space on the SSD so the whole of its SLC write cache can be used.<\/p>\n<\/blockquote>\n\n<p><a href=\"https:\/\/www.youtube.com\/watch?v=dqaDaPjWKoE\">SomeTechGuy<\/a>:<\/p>\n<blockquote cite=\"https:\/\/www.youtube.com\/watch?v=dqaDaPjWKoE\"><p>The price on added memory and SSD capacity on the otherwise excellent Mac Mini is horrible. I wanted to avoid paying the apple tax on that storage, so I am using an external SSD and it means I can get twice the storage for less than half the price. But I wanted to find out what it would mean for performance, and I couldn&rsquo;t believe what I found.<\/p><\/blockquote>\n\n<p>The Mac mini also has Thunderbolt 4, but he finds it limiting performance. The internal 256 SSD seems to be slow, despite what was <a href=\"https:\/\/www.macrumors.com\/2024\/11\/08\/m4-mac-mini-modular-storage\/\">reported earlier<\/a> about it using multiple chips like the larger versions.<\/p>\n\n<p>Previously:<\/p>\n<ul>\n<li><a href=\"https:\/\/mjtsai.com\/blog\/2024\/10\/30\/macbook-pro-2024\/\">MacBook Pro 2024<\/a><\/li>\n<li><a href=\"https:\/\/mjtsai.com\/blog\/2024\/10\/29\/mac-mini-2024\/\">Mac mini 2024<\/a><\/li>\n<li><a href=\"https:\/\/mjtsai.com\/blog\/2018\/11\/27\/poor-mac-performance-without-a-ssd\/\">Poor Mac Performance Without an SSD<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Ric Ford: Apple&rsquo;s exhorbitantly-priced Mac storage comes with impressive benchmark claims but has some serious, hidden bottlenecks in certain scenarios, as do other SSDs. David Harry illustrated this clearly in a video, using Activity Monitor as a novel window into dramatic SSD slowdowns when moving large amounts of data to an Apple internal SSD from [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"2025-03-18T18:26:36Z","apple_news_api_id":"0d121c50-3265-4146-89aa-55b0526543be","apple_news_api_modified_at":"2025-03-18T18:27:11Z","apple_news_api_revision":"AAAAAAAAAAAAAAAAAAAAAA==","apple_news_api_share_url":"https:\/\/apple.news\/ADRIcUDJlQUaJqlWwUmVDvg","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[2],"tags":[1407,30,557,100,2598,183,174,201],"class_list":["post-47128","post","type-post","status-publish","format-standard","hentry","category-technology","tag-activity-monitor","tag-mac","tag-macmini","tag-macbookpro","tag-macos-15-sequoia","tag-ssd","tag-storage","tag-thunderbolt"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47128","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=47128"}],"version-history":[{"count":2,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47128\/revisions"}],"predecessor-version":[{"id":47130,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47128\/revisions\/47130"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=47128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=47128"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=47128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}