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Old 29th July 2022
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jggimi jggimi is offline
More noise than signal
 
Join Date: May 2008
Location: USA
Posts: 7,983
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Quote:
Originally Posted by TCH View Post
I don't want to waste resources unecessarily by unneeded encryption.
Have you examined this resource consumption? It may not be as harmful as you assume.

I just did two tests:
  1. I used nc(1) to transfer 100M from RAM (/dev/zero) on a local sending system to a local receiving system's /dev/null. This took 15.8% of the receiving system's CPU during the transfer.
  2. I used ssh(1)/sshd(8) to transfer the same 100 MB of RAM-based zeroes, using encryption/decryption. It consumed 1.2% of the receiving system's CPU during the transfer.
This appears counterintuitive. Why would the CPU-heavy transfer consume *less* resource?

Well, CPU utilization is a measure of resource consumed over time. The transfer with encryption was significantly slower. The receiving server is CPU constrained, as it is an Alix embedded machine with a VIA/Geode 32-bit CPU running at 500MHz.
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