FAQ: inconsistent random 4K write speed results

AmorphousMemoryMark measures memory read/write performance in GB/s.
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katsura
Posts: 20
Joined: Sat May 23, 2020 6:16 pm

FAQ: inconsistent random 4K write speed results

Post by katsura »

Q: Is there a non-Mac App Store version of AmorphousMemoryMark?
A: No. AmorphousMemoryMark is only available on Mac App Store. https://apps.apple.com/app/amorphousmem ... 1495719766

Q: Why is the app icon so ugly?
A: I wish I could draw, paint, design app icons, and more. I will replace it with something nicer at some point. i.e. hire an icon designer.

Q: Why there are four different tests?
A: Four different tests represent different memory usages.
• SEQ128K Tn: Reading/writing one big memory block sequentially from multiple apps/threads.
• RND4K Tn: Reading/writing small memory blocks from multiple apps/threads.
• SEQ1M T1: Reading/writing one big memory block from beginning to end from one app/thread.
• RND4K T1: Reading/writing small memory blocks one at a time from one app/thread.

Q: What are these four tests actually doing?
A: Here are the technical details.
• SEQ128K T8: Reading/writing the specified size memory block sequentially (access all blocks in sequential order) with 128 KiB blocks from the specified number of threads.
• RND4K T8: Reading/writing the specific size memory block at random sequence (access all blocks in random order) with 4 KiB blocks from the specified number of threads.
• SEQ1M T1: Reading/writing the specified size memory block sequentially (access all blocks in sequential order) with 1 MiB blocks from one thread.
• RND4K T1: Reading/writing the specified size memory block at random sequence (access all blocks in random order) with 4 KiB blocks from one thread.

Q: Why is the number of threads limited to up to 64?
A: Unnecessarily increasing the number of threads will negatively affect the performance measurements due to extra thread-context switches.

Q: The score result green bar is not a linear scale?
A: It uses a logarithmic scale.

Q: The manufacturer name is a hexadecimal number.
A: If you know which manufacturer it is but the app is showing a hexadecimal number, please email me and let me know the manufacturer name and hexadecimal number. I’ll add it to the next app update.

Q: Why did you copycat the CrystalDiskMark GUI?
A: CrystalDiskMark uses easy to see measurement results in one simple window. Amazon reviews, tech article writers/editors, and even manufacturers use CDM to show the performance characteristics in a single screenshot. I just wanted something similar with AmorphousMemoryMark so that I, or we all, can compare different memory modules just by examining a single screenshot.

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