Increasing Memory Clock Reduces Hashrate

dood76dood76 Member Posts: 23
edited January 2018 in Mining
Hello there,

I am mining Ethereum with Claymore's Dual Miner V10.5. I am getting a total hashrate of 75MH/s using three GPUs. However, whenever I try to overclock the memory using MSI Afterburner, the hashrate on one of my cards actually goes down to 25MH/s from 19MH/s. This reduces my overall hashrate to 69MH/s. Each cards normally gets around 25MH/s.

Here are my specs:
1x Sapphire RX470 4GB Mining Edition
1x Asus Duo RX580 8GB
1x Asus STRIX RX580 8GB
Intel Celeron G3930
4GB Corsair Value Select DDR4 2133Mhz
MSI Z270 Gaming Plus
Corsair HX1200
Corsair ForceLE 120GB

Any help would be much appreciated, thanks.
Post edited by dood76 on


  • echomineechomine Member Posts: 8
    ~ the hashrate on one of my cards actually goes down to 19MH/s from 25MH/s.~

    this one should be the 4gb one.
    did you mean all your cards provides 75 with their stock ? for 8gb ones it could be but might not be for 4gb one
  • dood76dood76 Member Posts: 23
    Sorry, I meant 19 to 25, thanks. The hashrate goes down for any card I increase the memory clock on, regardless of if it's the 4GB or 8GB one.
  • echomineechomine Member Posts: 8
    edited January 2018
    sorry trying to understand better to comment.

    you have 3 4gb and 2 8gb

    so far I see, the stock mining values for 4gb is around 16
    and the 8gb is around 25

    if you OC them the values can increase 4-5 mh/s more..safely OC:)

    so how you get 75 from from 2 8gb and 1 4gb..
    is that mining edition 4gb can do 25 on stock settings?
  • dood76dood76 Member Posts: 23
    I have them all BIOS modded, each card doing 25MH/s.
  • kurthunkkurthunk Member Posts: 17
    You may want to try lowering the memory voltage when you increase the clock rate, or further reducing the core clock rate. When you increase the memory clock rate you are increasing the power to the card which may cause it to cut back in other ways.

    I run my 580s at:
    Core 1150 MHz/ 900 mV
    Memory 2100 MHz/ 900 mV

    I get about 29.5 per card with a modded bios. I can run the memory at 2150, but I need the power savings for the machine in general.
  • dood76dood76 Member Posts: 23
    Tried that, still does not work.
  • kurthunkkurthunk Member Posts: 17

    maybe you could share the BIOS mod you tried, and the core/memory voltages and speeds. 580s can typically get 30Mh/s. Identifying the memory manufacturer for each card also is important in picking your bios mod.
  • dood76dood76 Member Posts: 23
    I modded my BIOS according to this video:

    My core clock is: 1350Mhz
    My memory clock is: 2000Mhz
    I have not touched my voltages.

    In terms of the memory manufacturers, my RX580s have 8GB of Hynix memory.
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