bitcoind takes 670% CPU usage at first sync #6358

and a unix load of 6.41 even though I only have a Quad Core CPU. It renders my machine fully unusable. I set it's nice value to 10 for now.

http://puu.sh/iIDtg/021875dd2a.png

Which version? What arguments / bitcoin.conf settings? You're sure you don't have -gen=1 enabled?

You an try e.g. -par=1 to reduce the number of script verification threads. By default it uses as many threads as there are cores available minus one, but it may be mis-estimating this.

Can you find a message like this in your debug.log:

2015-06-29 09:35:16 Using 5 threads for script verification

0.10.2 x64

Config:

disablewallet=1
maxconnections=1000
timeout=10000
allowreceivebyip=1

bind=213.163.74.163:8333
bind=[2a00:1630:2:1901::b7c]:8333
rpcuser=bitcoinrpc
rpcpassword=xyz

addnode=node.bitcoin.xxx
addnode=x.jine.se
addnode=bitcoin.coinprism.com
addnode=btcnode1.evolyn.net
addnode=faucet.bitcoin.st

addnode=messier.bzfx.net

screen ./bitcoind -server

By now I rsynced the blockchain from my older node. CPU usage now at 1.8% after all blocks are present.

2015-06-30 21:05:40 Using 8 threads for script verification

Probably 8 because of HT.

So it looks like boost::thread::hardware_concurrency(), which is used to determine the default concurrency, also counts 'fake' HT cores. It is a bit disappointing but I'm not sure what underlying APIs for querying this that operating systems expose in any case.

There is also boost::thread::physical_concurrency() maybe it works better, as it claims not to count 'virtual cores'.

I'm marking this as fixed by #6361. Comment if this is not correct, please.