Bitcoin Forum

Hi all,

I looked through forums but found nothing. Sorry if someone already speak about it.

I build my mining rig last month and I start mining some altcoins (ltc, dogecoin).

I have three graphic cards Sapphire Radeon  R9 280X, 11221-02-40G. According to https://litecoin.info/Mining_hardware_comparison, the best config for me is : --scrypt --gpu-engine 1050 --gpu-memclock 1500 -I 13 -g 2 --thread-concurrency 8192
I tried many other config and yes it's the best. My hashrate is around 2100-2200 kH/s.

Everything was fine.

Last week, I not have choice and I have to move my rig to another place using a public University connection to Internet. This connection seems to be very restrictive and when I launch mining, it's not work. I have messages like this :

No servers were found that could be used to get work from.
Please check the details from the list below of the servers you have input
Most likely you have input the wrong URL, forgotten to add a port, or have not set up workers

I'v tried many things like using a pool with port 80 enabled but nothing work. So I thing about using a VPN and I install http://www.vpnoneclick.com/ because it's simple and free to test. I'm on Ubuntu. I launch this VPN I then I was able to connect to all pools.

Cool. But now my hashrate is 1100 kH/s and no 2100 kH/s like before. So my question is : Using VPN can reduce hashrate ? I think the answer is no but then what's happen to me ? I use the same config as before.

Thanks for your help and sorry for my english!

it shouldnt reduce the machine hashrate but will reduce the hashrate on the pool side due to it taking longer to go through the vpn and back out. it will show alot more stales as it has to do an extra hop which adds time to the requests and submits

miner ---(20ms)--- pool
miner ---(20ms)--- VPN --- (15ms) --- Pool
the longer it takes for your work to get back to the pool the more likely someone else has solved and subbmitted the share already/

Thx for your answer

Any workaround? A "faster" VPN?

I read some articles that people use VPN to be closer to pool to get faster than without VPN. So it should be possible to increase my hasrate?

a good VPN would be better. try www.privateinternetaccess.com
there pretty decent and you can pay with bitcoins.

its pretty much down to trial and error. which pool are you using?

vpn dont reduce hashrate!

I will tried this VPN. Thx.


Coinotron for LTC and Dogehouse for DOGE.

My hashrate is divided by two on both (compared before at home on these same pools)

Hi,

I bough privateinternetaccess.com and my hashrate increase to 2100 kH/s.

So using some VPN like vpnoneclick.com can reduce hashrate.

vm1990> Thx for your help!