# Mining memory requirements doesn't match specifications

**URL:** <https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418>\
**Category:** Mining\
**Created:** [September 1, 2016, 5:24am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418 "2016-09-01T05:24:28Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![ChronoBank](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/chronobank/32/382_2.png) [@ChronoBank](https://forum.zcashcommunity.com/u/ChronoBank)\
**Post date:** [September 1, 2016, 5:24am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/1 "2016-09-01T05:24:29Z")

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Ladies and gentlemen,

I’ve set up a VM mining node under Ubuntu with 8 virtual cores CPU (host have the same) and 4Gb memory

It was written that memory requirement is 700 Mb per core.

However, my virtual machine uses just 2 Gb memory from 4Gb (including OS) and swap is 100% free.

In theory zcashd should use 8x700Mb=5600Mb

Is that OK?

PS: Mining works, I mined 2 blocks so far

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**Author:** ![Voluntary](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/voluntary/32/4343_2.png) [@Voluntary](https://forum.zcashcommunity.com/u/Voluntary)\
**Post date:** [September 1, 2016, 6:12am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/2 "2016-09-01T06:12:15Z")

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Unless you’ve changed the genproclimit in your configuration file, you’re probably mining with one core.

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<div class="post-metadata">

**Author:** ![ChronoBank](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/chronobank/32/382_2.png) [@ChronoBank](https://forum.zcashcommunity.com/u/ChronoBank)\
**Post date:** [September 1, 2016, 9:16am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/3 "2016-09-01T09:16:28Z")

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Thank you!

Does speed increase linear with amount of cores?

Or 8 cores give less than 8x performance?

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<div class="post-metadata">

**Author:** ![ChronoBank](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/chronobank/32/382_2.png) [@ChronoBank](https://forum.zcashcommunity.com/u/ChronoBank)\
**Post date:** [September 1, 2016, 9:39am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/4 "2016-09-01T09:39:54Z")

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Strange, I set genproclimit, mining eats much more memory, cpu load = 700%, however benchmark when gen=0 still works on 1 core and cpu load =100%.

used benckmark:  
~/zcash/src/zcash-cli zcbenchmark solveequihash 10

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<div class="post-metadata">

**Author:** ![Shawn](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/shawn/32/187_2.png) [@Shawn](https://forum.zcashcommunity.com/u/Shawn)\
**Post date:** [September 1, 2016, 11:05am UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/5 "2016-09-01T11:05:49Z")

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Solve Equihash runs by default on a single thread, you can add more with a thread argument:

`time solveequihash NUM_ITERS [NUM_THREADS]`

More info here: [How do i check my hashrate? - #40 by daira](https://forum.zcashcommunity.com/t/how-do-i-check-my-hashrate/672/40)

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<div class="post-metadata">

**Author:** ![ChronoBank](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/chronobank/32/382_2.png) [@ChronoBank](https://forum.zcashcommunity.com/u/ChronoBank)\
**Post date:** [September 1, 2016, 1:33pm UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/6 "2016-09-01T13:33:50Z")

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LOL! 4 cores were 2 times slower than 1 core. 120sec vs 50 sec averages

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<div class="post-metadata">

**Author:** ![Voluntary](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/voluntary/32/4343_2.png) [@Voluntary](https://forum.zcashcommunity.com/u/Voluntary)\
**Post date:** [September 1, 2016, 2:12pm UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/7 "2016-09-01T14:12:47Z")

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The proof of work used by the Zcash miner is designed to consume memory bandwidth so that a system’s memory bandwidth becomes the limiting factor rather than the system’s processors. Beyond one or two cores, extra cores are just competing for a resource that isn’t available.

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<div class="post-metadata">

**Author:** ![zawy](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/zawy/32/11892_2.png) [@zawy](https://forum.zcashcommunity.com/u/zawy)\
**Post date:** [September 1, 2016, 6:00pm UTC](https://forum.zcashcommunity.com/t/mining-memory-requirements-doesnt-match-specifications/1418/8 "2016-09-01T18:00:03Z")

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The multithread benchmark does not work. Just check 1 thread.