We can see the following examples, they used 4 GPUs:
Hashtype: SHA1 Speed.Dev.#*.....: 25963.3 MH/s
it took Google 110 GPUs (?) and 1 year to find a SHA-1 collision:
Nine quintillion (9223372036854775808) SHA1 computations in total
to create a SHA1 collision.
1 year = 31540000 seconds.
pw rig url SHA1: 25963.3 MH/s = 25963300000 H/s / 4 = 6490825000 H/s/GPU
so according to the pw rig website, 110 GPU could do sha1: 31540000*6490825000*110 = 22519268255000000000
and Google did: 9223372036854775808
so the GPU that was used in the pw rig is 2.4x times faster regarding SHA-1 that the GPU used by Google?
The Question:: are the calculations correct?