On testnet, I found that a sievesize=6144000 outperformed every other sievesize I tried (incl. 6000000 & 6246400) by 30% using an i7.
However, when i try to use this sievesize mining live, h5 crashes as soon as mining starts (every time). It's unfortunate because it showed such promise on testnet.
Blocks were coming in 4-5 chunks at a time steadily, even hit 6 blocks in 1 minute (no other setting hit above 4 blocks/min).
same here, 6144000 crashed h5 as soon as it attemps to mine on a i7 3770k with 16gb of ram.
Did you get better results on testnet with 4M than 1M ?
How do you activate testnet ? I can't check it on the debug window.
The best sievesize's I found were ...
Build - Sievesize - PPS - Blocks in 10 minutes
HP3 - 1000000 - 7387 - 14
HP5 - 2000000 - 7092 - 14
HP5 - 4000000 - 7911 - 15 (3 at a time usually)
HP4 - 6000000 - 7819 - 15
HP4 - 6144000 - 7430 - 20
HP3 - 6553600 - 5042 - 20 (steady 2 per minute)
HP5 - 5000000 - 7815 - 22
HP5 - 6000000 - 6919 - 23
HP5 - 6144000 - 7876 - 29 (4 at a time usually + 6 in 1 minute) - same result using "-1" or "6" threads.
Nothing above 4608000 worked for me mining live w/HP5 and using higher settings live w/HP3 worked (without crashing) but was yielding very low PPS (in the hundreds) live.
I get a higher PPS @ 1M or 2M live on HP5.
I have no idea if the testnet actually "test" anything to be honest.
None of the data I collected translates over into real world mining ... especially since the client shuts down and no blocks are being found for days using the same settings that worked so well on the testnet.
So I'm trying the highest testnet settings that yielded the best results that will still work live and seeing how it goes. So far (6 hours or so, no blocks).
To answer your question ... add "-testnet" to the command line.