Consider this test:
http://www.webpagetest.org/result/121101_A9_9RC/1/details/
You gave “B” for Time to First Byte: 92 ms (request #1); But even google analytics Time to First Byte: 122 ms (request #13).
Something is wrong with score? Or not?
The first byte time grade includes the DNS, socket connect, server response time and any redirects. No redirects in this case but it looks like the DNS lookup time may be what pushed the grade into “B” territory.
We use the socket connect time as a rough RTT estimate and budget for 1 RTT for the DNS time. Anything longer than that will subtract from the overall performance.
[quote=“pmeenan, post:2, topic:7817”]
No redirects in this case but it looks like the DNS lookup time may be what pushed the grade into “B” territory.[/quote]
Hmmm… DNS below 0.2s and green bar shorter than google (request #13)… there should be some “border-line”… if you are in, then grade “A”.