what are the benefits of the delegated harvesting
from:
http://support.ournem.com/knowledgebase.php?article=13Which is better? Local or delegated harvesting?
Local harvesting is the default option and implies you are harvesting on your local computer where you have both the node (NIS) and the wallet (NCC) present. Simple to use. All the control of NEM, XEM, uptime and harvesting is in one machine and it's owner. When that machine is not working (or disconnected) there is no supporting of the NEM network, no harvesting and no synchronizing with the network - that means that when that machine is started again it can take some time before it is synced with the network so that transactions can be seen or made.
If 24/7 harvesting is planned on local, everyday PC, the cost of electricity will be higher than setting up a node on some VPS or Raspberry Pi
Delegated harvesting is awesome and uniqe feature of NEM. It implies transfering of your importance to some other node (NIS) (it can be whatever node your wallet (NCC) connects to - even your own and even local). To enable delegated harvesting the transfer of the importance must be done by a special transaction and it needs time (6 hours). After it is activated, wallet (NCC) can access a remote (or local) node (NIS) and harvest using the resources of that node even if the computer where the wallet is turned off or offline.
For example: my friend has a Raspberry Pi that is always online and working. He installs NIS on it and both my friend and I can connect with our desktop PCs to that Raspberry Pi computer to harvest, issue transactions etc. When either or both of us turn off our PCs, harvesting will continue for both of us.
Security is very high or even better then local harvesting since no keys left our PCs. So if his Raspberry Pi is hacked or stolen or whatever - we are safe. Like we used offline wallets. Also, when if we dont turn on our PCs for a month and then want to check our XEM balance or issue transactions we don't have to wait for the syncing of the NIS because Raspberry was doing that all the time. The drawback is that I have to relay on my friend that he will have that Raspberry Pi working.
For both types of harvesting the account must have at least 10 000 XEM vested.
Pros and cons:
Local harvesting:
+ No setup required - just click Start local harvesting
- No offline harvesting
- Time to synchronize if turned off for a while
- Potential security risk from unauthorized access to the machine because of available wallet files
- Higher cost for electricity if run on regular PC vs delegated on VPS or Raspberry Pi
Delegated harvesting:
+ Better security because wallet is not on the same computer that is exposed to the network
+ Lower cost of harvesting
+ Fast connecting to the network (no syncing)
+ Always harvesting (even if desktop/main PC is turned off)
- Needs time to activate/deactivate (6 hours)
- Needs the address of the remote node (if localhost is not used)
Importance is the same on both options so harvesting chance and/or rewards will be the same either way.
If delegated harvesting is used to harvest on local (same) computer than it is virtually the same as local harvesting.
More detailed explanation how local and delegated harvesting works:
http://blog.nem.io/how-local-and-delegated-harvesting-works/