Would the Intel SHA extensions help in creating SHA1 collisions? AMD Ryzen and EPYC supports them.
If you break the attack into two phases, like in the SHAttered paper, it may help the first phase. The researchers say that they used a CPU cluster for the first phase; the more expensive second phase used a GPU cluster.
...from an attacker’s point of view, it may seem best to implement the attack on a CPU in order to be able to claim a better attack complexity. However, a GPU being far more powerful, it is actually much more efficient to run it on the latter: the attack of  takes only a bit more than four days to run on a single GTX 970, which is much less than the estimated 150 days it would take using a single quad-core CPU.
The trade-off is that GPUs may be more difficult to program, but on the plus side, they are more cost-effective.