Router CPU pegged for TestMy.net but not speedtest.net

[Vinn]

I am getting very varied results from speedtest.net and testmy.net. Now, before everyone hounds me, I read the sticky about some of the differences in measurement methods. Im getting consistent 180Mb download from speedtest and 18Mb down from speedtest.net. This seems to follow the pattern of alot of the other posts I've seen: a 10:1 ratio of estimated speeds between these sites' tests.

 

However, I have an interesting note to add to the conversation.

• At 180Mb down from speedtest, my router (AC66R runnin Merlin 380.57) is seeing about 35% CPU usage.
• At 18Mb down from testmy.net, my router is pegged at 100% CPU.

 

Is there some distinct difference in the type of traffic that would cause a CPU bottleneck in my router?

[mudmanc4]

That is 'odd' behavior.

I might run a few multithread tests for comparison, see what you get there.

[Vinn]

I did some testing with multi-threaded enabled. 

 

Same laptop: Thinkpad T430. Windows 7, 8GB, i5 3320M. Intel 82579LM Gigabit, Centrino Advanced N 6205. right next to router

Router:  AC66R runnin Merlin 380.57

• With 1Gb ethernet: 18Mb down 
• With 5Ghz - 16Mb down 
• With 2,4Ghz - 15Mb down 

 

All tests pegged the CPU in my router.

 

Interestingly. I used my HTC One M8 to try the Lite tests on my 5G channel and saw 64Mb down! And router CPU was only about 50%. So is there some kind of difference in the traffic coming from my Lenovo vs my phone that is causing the router to work much harder? I'm not very network savvy, but maybe my laptop is making more work at the packet level for the router??? What can I try next to investigate?

[mudmanc4]

As I understand it, there should be no difference in testing at testmy.net than downloading a large webpage or file, same ports same protocol.

 

My thoughts are the router has some unconventional routing going on. Which could be one or ten of five million.

 

Are you able to flatten the router to factory defaults?

[Saving the current config if you have a lot going on prior}