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<p>What you mentioned is a specific case and not a generic
situation. The main point there is that RAID 5 or 6 impacts write
performance compared when you write to only 2 given disks at a
time. That was the comparison made.<br>
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<p>Fernando<br>
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<div class="moz-cite-prefix">On 07/08/2017 16:49, Fabrice Bacchella
wrote:<br>
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cite="mid:034E384B-4B32-4FBC-A760-404EB38EBC86@orange.fr">
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<div class="">Le 7 août 2017 à 17:41, FERNANDO FREDIANI <<a
href="mailto:fernando.frediani@upx.com" class=""
moz-do-not-send="true">fernando.frediani@upx.com</a>> a
écrit :</div>
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<div class="">
<p style="font-family: Helvetica; font-size: 12px;
font-style: normal; font-variant-caps: normal;
font-weight: normal; letter-spacing: normal; orphans:
auto; text-align: start; text-indent: 0px; text-transform:
none; white-space: normal; widows: auto; word-spacing:
0px; -webkit-text-stroke-width: 0px; background-color:
rgb(255, 255, 255);" class="">Yet another downside of
having a RAID (specially RAID 5 or 6) is that it reduces
considerably the write speeds as each group of disks will
end up having the write speed of a single disk as all
other disks of that group have to wait for each other to
write as well.<br class="">
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That's not true if you have medium to high range hardware raid.
For example, HP Smart Array come with a flash cache of about 1 or
2 Gb that hides that from the OS.
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