Dear Cubirez
I modified the bios of my Saphire RX470, but I could not put the memory clock to more than 1900.
If I put it above the pc hangs.
And the most I got was 670
How is it possible to do 900 h / s?
Thanks
Almir Fiorio
Read carefuly, he said a few post above that most of the shares were stales, making his 1100H/s not effective at all.
You can increase your hashrate a bit by overclocking the memory and modifying your bios.
Simple copy of your 1500 mem strap on the 1625/1750/2000 mem straps should increase your hashrate a bit.
If you want a bigger increase of your hashrate (up to 900 as xneoenx pointed out), you need custom mem strap which are much more complicated to figure out. As far as i know, these aren't being shared for free atm.
You need to be more specific here:
How did you modify your BIOS, what memory is on your GPU (Hynix/Elpida/Samsung)?
What are your other settings aside of mem clock (core clock, core voltage, mem voltage) ?
My rig is running at an average of 725 H/s/card (lowest card ~690H/s, fastest ~760H/s) so i can't help you much if your target is to increase the hashrate to 900 H/s :p