Slow sync arb_node with geth

The Arbitrum node is very different from standard Ethereum nodes, that is why we provided a public endpoint initially, and now there are other 3rd party providers available like Alchemy and Infura.

When Arbitrum Nitro is released, it will be the same as running a standard geth node, but until then, there will be growing pains. To get decent performance, you need a fast NVMe with high IOPS, SSD is too slow. It takes about 3 days to sync from scratch with fast NVMe. There is no fast mode right now. We have been improving speed with each release, and have more speed improvements in the works.