[kwlug-disc] [GTALUG] block size for dd -- no difference

[Khalid Baheyeldin]

On Wed, Sep 3, 2025 at 7:17 AM Ron <ron at bclug.ca> wrote:

> So, in this situation (perhaps a flawed test?), there's a dramatic
> speedup going above bs=1, a significant speed improvement going above
> bs=1000, and slight decreases in speed going above bs=1,000,000.
>
> Similar results on an SSD, but *slower* on the low end and faster at
> bs=1000000 (1M).
>
> SSD results also slowly decline above bs=1M:
>

Looks like bs=1M is the sweet spot, regardless of disk technology.
Perhaps it is about round trips into the kernel and out (as Chris Frey said
in the other thread).

Thanks for doing the tests ...
-- 
Khalid M. Baheyeldin
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