{"id":"external-drives.why-does-copy-speed-drop-partway","url":"/faq/external-drives/why-does-copy-speed-drop-partway","category":{"id":"external-drives","title":"External drives"},"subcategory":{"id":"speed-and-hardware","title":"Speed, cables and hardware"},"question":"Why does my external drive's copy speed drop partway through a big copy?","alt_questions":["SSD fast at first then slow","Copy speed drops after a few gigabytes","External SSD slows down during large transfer","why does my transfer start fast then crawl"],"short_answer":"Many SSDs write into a fast cache first and slow down once it fills, and drives slow themselves when warm. A copy that starts fast and settles lower is normal; a crawl or disconnects point to a cable, connection or heat problem.","answer_markdown":"Many SSDs write very quickly into a fast cache area first, then slow to their normal speed once that cache is full — so a large copy starts fast and settles lower. A drive that gets warm may also slow itself to protect the hardware. Hard disks are naturally a little slower toward the end of the disk.\n\nNone of this is a fault. If speed collapses to a crawl, or the drive disconnects, check the cable and connection and see [whether it's normal for the SSD to get hot](/faq/external-drives/do-external-ssds-get-hot). Long moves in Storage Studio simply take longer; you can keep working meanwhile.","answer_html":"

Many SSDs write very quickly into a fast cache area first, then slow to their normal speed once that cache is full — so a large copy starts fast and settles lower. A drive that gets warm may also slow itself to protect the hardware. Hard disks are naturally a little slower toward the end of the disk.

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None of this is a fault. If speed collapses to a crawl, or the drive disconnects, check the cable and connection and see whether it's normal for the SSD to get hot. Long moves in Storage Studio simply take longer; you can keep working meanwhile.

","answer_text":"Many SSDs write very quickly into a fast cache area first, then slow to their normal speed once that cache is full — so a large copy starts fast and settles lower. A drive that gets warm may also slow itself to protect the hardware. Hard disks are naturally a little slower toward the end of the disk.\n\nNone of this is a fault. If speed collapses to a crawl, or the drive disconnects, check the cable and connection and see whether it's normal for the SSD to get hot. Long moves in Storage Studio simply take longer; you can keep working meanwhile.","tags":["ssd","cache","copy speed","heat"],"related":[{"id":"external-drives.do-external-ssds-get-hot","question":"Is it normal for my external SSD to get hot during big moves?","url":"/faq/external-drives/do-external-ssds-get-hot"},{"id":"external-drives.why-is-my-external-ssd-slower-than-advertised","question":"Why is my external SSD slower than the speed on the box?","url":"/faq/external-drives/why-is-my-external-ssd-slower-than-advertised"},{"id":"external-drives.why-are-many-small-files-slow-to-copy","question":"Why is copying lots of small files so much slower than one big file?","url":"/faq/external-drives/why-are-many-small-files-slow-to-copy"}],"applies_to":"all","last_reviewed":"2026-10-01","title":"Why does my external drive's copy speed drop partway through a big copy? — Storage Studio FAQ","description":"Many SSDs write into a fast cache first and slow down once it fills, and drives slow themselves when warm. A copy that starts fast and settles lower is normal; a crawl or disconnects point to a cable, connection or heat problem.","crumbs":[{"name":"Home","path":"/"},{"name":"FAQ","path":"/faq/"},{"name":"External drives","path":"/faq/external-drives/"},{"name":"Why does my external drive's copy speed drop partway through a big copy?","path":"/faq/external-drives/why-does-copy-speed-drop-partway"}],"jsonld":{"@context":"https://schema.org","@type":"FAQPage","url":"https://storagestudio.us/faq/external-drives/why-does-copy-speed-drop-partway","inLanguage":"en","dateModified":"2026-10-01","mainEntity":[{"@type":"Question","name":"Why does my external drive's copy speed drop partway through a big copy?","alternateName":["SSD fast at first then slow","Copy speed drops after a few gigabytes","External SSD slows down during large transfer","why does my transfer start fast then crawl"],"acceptedAnswer":{"@type":"Answer","text":"Many SSDs write very quickly into a fast cache area first, then slow to their normal speed once that cache is full — so a large copy starts fast and settles lower. A drive that gets warm may also slow itself to protect the hardware. Hard disks are naturally a little slower toward the end of the disk.\n\nNone of this is a fault. If speed collapses to a crawl, or the drive disconnects, check the cable and connection and see whether it's normal for the SSD to get hot. Long moves in Storage Studio simply take longer; you can keep working meanwhile.","url":"https://storagestudio.us/faq/external-drives/why-does-copy-speed-drop-partway"}}]},"fragment":"
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External drives · Speed, cables and hardware

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Why does my external drive's copy speed drop partway through a big copy?

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Short answer: Many SSDs write into a fast cache first and slow down once it fills, and drives slow themselves when warm. A copy that starts fast and settles lower is normal; a crawl or disconnects point to a cable, connection or heat problem.

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Many SSDs write very quickly into a fast cache area first, then slow to their normal speed once that cache is full — so a large copy starts fast and settles lower. A drive that gets warm may also slow itself to protect the hardware. Hard disks are naturally a little slower toward the end of the disk.

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None of this is a fault. If speed collapses to a crawl, or the drive disconnects, check the cable and connection and see whether it's normal for the SSD to get hot. Long moves in Storage Studio simply take longer; you can keep working meanwhile.

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