Polaris 21 Based Sapphire Radeon RX 550 2GB with Elpida Memory – 490 h/s

Scratchpad: 2MB

{ "index" : 0,
"intensity" : 432, "worksize" : 12,
"affine_to_cpu" : false, "strided_index" : true
{ "index" : 0,
"intensity" : 432, "worksize" : 12,
"affine_to_cpu" : false, "strided_index" : true

Hello again.

Here is the link to the modified BIOS (unlocked shaders) for Sapphire Radeon RX 550 2GB with Elpida memory.



My modest tests with stock GPU frequency and overclocked memory:


Of course you can do your own experiments. I think that better results can be achieved by overclocking the frequency of the GPU, but with more power draw.. Enter your result in the comment!

Good luck.

Mariusz Zoolek, mariusz.zoolek(at)gmail.com

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curious would this work on a gigabyte rx550? d5 2gb

what string did you change in the hex code if you dont mind me asking was it the ‘6F’ ?, just seeing if this can be applied to other makes cheers!!!!



doesnt seem to be working on gigabyte rx 550 d5

hex > 6F227022 => 6F226F22 , save
polaris> fix > save rom
atiwinflash > program rom


no idea if its bsod or crashing on windows im running multiple gpu’s , just had a reduced hashrate, gpu z still reported 512 shadera



I have that exact card, used your bios, unlocked additional shaders but didn’t gain any hashrate. Before my setup was:
flashed bios, memory oc 1875/950 and the card was doing 475 h/s.

Although your bios unlocked 128 more shaders there’s no performance gain. Why did you use worksize: 12?
My config amd-stak :
{ “index” : 0,
“intensity” : 432, “worksize” : 8,
“affine_to_cpu” : true, “strided_index” : true
{ “index” : 0,
“intensity” : 432, “worksize” : 82,
“affine_to_cpu” : true, “strided_index” : true

Are you also mining with cpu (is there any gain by not affining the gpu to cpu)?



Mati Thian Yami

Worksize 82?


Typing error. Used your settings, no gain of hashrate. Can you test it with the new version of xmrstak. You can manipulate memory chunk. Gave me an extra 20 hashes. Will try your bios again and the new version of xmrstak to see if i can go over 500h/s.


Currently its 485 h/s. Changed the chunk mem to 8 and stridex index to 2 in the new version of xmr stak.

Im still on the 640 shaders bios modified by one time click.

Do you think unlocking shaders to 768 will boost my hashrate?


Will try to do that and post the results.




Flashed the bios, have 768 shaders, memory at 1950/850 and doing 505 h/s.
I also have a XFX RX 550 4g, doing 420 h/s with flashed bios.
Can i do anything to improve the hashrate of this Gpu?
Is there a custom bios for this card?


Will send it to your mail. Hope theres something we can do. Did you increase the power limit of your gpu when overclocking?


So you use the RX 550 with 640 shaders originally (Lexa chip) to unlock additional 128?

xmr user

I have old version of Sapphire rx 550 2gb -Lexa with Elpida GDDR5 memmory.
I`m getting stuck on 550 H/s
stable oc @ core clock 1395 , mem clock 1940 (will go mhz-by-mhz).

Do you have a link for step-by-step bios mod?

my amd file looks like:

gpu_threads_conf” : [
// gpu: gfx804 memory:1664
// compute units: 8
{ “index” : 0,
“intensity” : 960, “worksize” : 8,
“affine_to_cpu” : false, “strided_index” : 1, “mem_chunk” : 2,
“comp_mode” : true

Any help is much appreciated !!!


Thx for your bios with 65282 mv setting on the core, now if have bricked my card.