It *could* be caused by the PoS minter thread going nuts (I've got slightly over 500 transactions in one wallet, all spent and the PoS minter thread constantly eats 25% cpu). Can someone with a large amount of transactions in wallet try my latest git version? Download, compile and run it with "-no-pos" parameter.
I can try it, I did have a very small payout treshold set at the pool, left miner running on several servers for a few months and didn't care much about it and I ended up with over 1000 transactions, the current client now takes tens of minutes to start... Plus after I make a transaction from the client, it hangs for another few minutes.
Where can I find your latest git version? Is it the official one at
https://github.com/yacoin/yacoin ?
It certainly won't fix the long start-up time issue as that's a completely unrelated performance problem (working on a fix). Making a transaction is also quite computationally-intensive task (signing hundreds of inputs with ECC crypto takes time). My latest commit just completely disables the proof-of-stake minting thread when given "-no-pos" commandline argument as I noticed it consumed quite a bit of CPU time on my PC even when not doing anything with the wallet and having exactly 0.00 YAC balance (with 500 spent transactions).