Bitcoin Forum

Alternate cryptocurrencies => Mining (Altcoins) => Topic started by: matmator on February 11, 2017, 01:50:30 PM



Title: Need advice on setting rx 480 nitro
Post by: matmator on February 11, 2017, 01:50:30 PM
Hello everyone

I am looking for a solution to my problem:

On my pc for gaming

I have 2 rx 480 nitro

I do not modify my bios to take advantage of the latest AMD driver (17.1.2).

I have windows 10.

With my rx480 nitro + @ 1342mhz / 2000mhz memory

I get 27.3 mh / s with the following settings: 1125 mhz / 2200 memory and -100mv

With my rx 480 nitro @ 1276 / 2000mhz memory

I get 24.5

Regardless of the memory setting at 2050, 2100 or 2200. I have no hashrate gain.

I try these settings: 1000mhz / 2000mhz memory -30mv

With this setting -276 mhz in clock and - 30mv I have no loss of hashrate but a gain in W.

Why does my card have no hashrate gain when I change the frequency of memory?

Thank you in advance if you have the solution

cordially


Title: Re: Need advice on setting rx 480 nitro
Post by: Tmdz on February 11, 2017, 03:59:54 PM
drop gpu core to 1100 mhz to save power, it will hash just as fast and you can do -98 mv for the undervolt.

On my rigs gpus that are not on the main pci x16 slot can not oc the memory by software.  You need to mod the bios and then it will run at whatever memory speed you put in the bios.


Title: Re: Need advice on setting rx 480 nitro
Post by: deadsix on February 11, 2017, 05:30:25 PM
Hello everyone

I am looking for a solution to my problem:

On my pc for gaming

I have 2 rx 480 nitro

I do not modify my bios to take advantage of the latest AMD driver (17.1.2).

I have windows 10.

With my rx480 nitro + @ 1342mhz / 2000mhz memory

I get 27.3 mh / s with the following settings: 1125 mhz / 2200 memory and -100mv

With my rx 480 nitro @ 1276 / 2000mhz memory

I get 24.5

Regardless of the memory setting at 2050, 2100 or 2200. I have no hashrate gain.

I try these settings: 1000mhz / 2000mhz memory -30mv

With this setting -276 mhz in clock and - 30mv I have no loss of hashrate but a gain in W.

Why does my card have no hashrate gain when I change the frequency of memory?

Thank you in advance if you have the solution

cordially

Not modding your BIOS is losing out on essentially free hashing power. Different memory clock speeds have different memory timings associated with them by default in the card's memory timings table.
Like there's one memory timing strap from 1500-1750, then another from 1750-2000, and another for 2000+ etc. As you overclock your memory, it picks and uses the relevant memory timings from the above table.

Some GPU mining algo's depend as much on the memory timing as on the memory clock speed. So as you go higher in clock speeds your card uses progressively looser timings and thus Hashing performance sees no increase. Now these default timings are very conservative but insure 100% stability. What BIOS modding essentially does is hardcode more aggressive timings and force the card to use them at higher clocks.
For instance, you can copy the 1750-2000 timings to the 2000+ memory strap and then you would see an almost linear gain with overclocking. You can also experiment and try even more aggressive timings, like using the 1500-1750 strap for 1750-2000 as well as 2000+ range but stability would become an issue. Experiment and see what works best for you.


Title: Re: Need advice on setting rx 480 nitro
Post by: matmator on February 11, 2017, 11:43:13 PM
Thank you for answering,

I do not want to modify my bios because it is my pc for the gaming has the base, and I mine when I do not play.

And I can not get my bios modified with the last driver relive crismon :(

I try to optimize my gpu maximum with original bios.