Got bored and ran simple tests on three of the older PCs in the house I've upgraded from 7/10 to 11.
When I say simple I mean simple. Ran a HD YT video in Firefox w/adguard installed to see how much CPU each would use. Figured internet browsing and office type work would be common use on older PCs.
1) Dell OP 780 SFF, Intel Q6600 4/4 (core/threads) 2.4GHz, 8gb DDR2, Original OS 7 Pro, Manufacturer date 2009
2 Acer X3300, AMD Phemon X4 925 4/4 2.8GHz (originally had a Athlon II X4 620) 8gb DDR2, Original OS 7 Home Manufacturer date 2009 (2010 CPU)
3) Acer R5-571T laptop, i5-6200u 2/4 2.3GHz 8gb, Original OS 10 Home, Manufacturer date 2016
Note: All have SSDs installed.
Cinebench R23 test results Avg
1) 1231
2) 1516
3) 1660
First I loaded W10 and then Linux Cim Mint 21.2 and all three showed ~40-55% utilization of the CPU with both OSs
Now here's the kicker, installed W11 and CPU utilization dropped to 20-30% for the same video
MS has been claiming 11 is better at resource management and it appears from this they're right.
Sorry I didn't record mem use, it completely slipped my mind to do so.
Note: To install W11 I used Rufus to bypass the HW checks on all three
BTW: For comparison the same video on my more recent built, AMD Rysen 5 5600g which has a R23 score of ~13,000, it used 1-3%