Low hash rates, rx570 4gb zombie pciex16

[opadfnezig]

I have 2 rigs and 3 rx570 4gb gpus.
Motherboards are Msi b450 gaming +(this is my main pc, that’s why), and asus prime h270. So, due to specs, h270 has 20 pci channels, and B450 16? or 8 +8(i haven’t found any chipset specs,but due to bios setups only 16).
The problem is that hashrate is too low. It should be 20-30 but i have less than 18 from each gpu. In asus board only 1 slot used, in msi both.
I’ve tried different configs, bios settings, vbioses, miner settings but the summary result was about 35mhs(11,16 on b450, 16-17 on h270). Theoretically I should have 20-30 mh/s from each gpu, but no… I understand why i can’t have so much performance on x8 ports(btw 11.9 and 15.64 mhs) but what’s the problem in the first case?

I think gpus are ok, as bought it from different people(there is only problem with 1 of it, some bad shares, and i think it might be a board problem).

So… I need advices as I have no clue how to solve the problem. My friend has about 50 mhs from 2 gpus in similar config(same gpu model), I have only about 45 from 3 gpus.

On my opinion the problem is in boards, but which one should I choose than?

P.S. Sry for my english.

[farkeytron]

H270 and the B450 motherboards tend to not have two x8 slots. Usually Z270 and X470 motherboards have the capability to run two slots in x8 mode.

Usually, boards with those chipsets have an x16 slot coming from the CPU and an x4 slot wired to the “southbridge” chip.

Having only an x4 secondary slot would explain why you’re getting poor zombie mode performance in the extra slot, but you should be getting full zombie mode performance from the x16 slots, at least in lolminer.

What are your miner settings? Did you use the recommended ‘dag limit’ settings below?

https://www.facebook.com/hiveos/posts/-attention-miners-with-4gb-amd-cardshello-hivers-last-night-ethereum-reached-epo/2866527216971010/

[opadfnezig]

Ah, forgot to say, I’m using lolminer with default settings. Now tried --4g-alloc-size 4078. On 4080 only 1 rig works(h270 and very bad), on 4078 nothing changed, h270(maybe became slightly better, 1-2 mhs), and b450

, it’s just much worst. Could you suggest chipsets or motherboards? I have also one on B150M but it doesn’t sounds like I need to try it. Of course, I’ll wait for several hours to see if it really so bad, but at least, after 5-10 mins without this setting I had better results than now. Also, maybe I should do something with my BIOS settings? Just let me know.

UPDATE, just cheched out b450’s output, and saw gpu fault detected 146 for same address. Don’t know what does it mean, just saying. Maybe theese are errors which leads to bad shares.

[opadfnezig]

UPDATE 2
Just tried to remove 1 gpu from B450, and now I have about 26.16 hashes from this gpu. So, seems like the promlem is in motherboard. But I don’t know what’s wrong with h270, and which board should I buy for mining.

[farkeytron]

Not for mining with 4GB cards… zombie mode in lolminer requires a ‘high bandwidth’ slot to get a decent hashrate from a 4GB card.

You’d need a fairly fancy motherboard (something with 2-3 electrically x8 or x16 slots) to get 26MH from each card

Try the B150M with the other card and see if it does any better.

[opadfnezig]

I don’t know what’s wrong with h270(even pcie version is the same), but… You know, seems like I have a box from B150M and absolutely different board in it(am3, don’t remember exactly). Maybe I’ll try or think about mining eth on 4g cards later, but now I’d like to try MWC, FIRO, seems like in my case eth doesn’t worth it. I’ve done some experiments and would like to share the results.
In B450 I have a bios setting wich allows me to control prcie configs. I’ve tried different versions and modes(like 8+8) and checked hashrate.
Gen1 - 10mhs
Gen2 - 20mhs
Gen3 - 26mhs(theoretically 40).
Gen3 8+8 gives 20 mhs from each gpu(but i had only 1 gpu in the board so…)
The strangest thing is that I heard about people using like 775 boards(g2 pcie) and having about 25 mhs, but seems like it’s not possible anymore.
Also I’ve tried different chipset pcie gens, but seems like it doesn’t have any influence on hashrate(it’s not connected to southbridge in my case).

Anyway, if you know any motherboard with good pcie config(as i understand, it should be g3), it would be useful information for me. I’ll update topic if I get any new informtion, but this kind of mining dies, so I see no sence to buy boards now if it’s possible to have same results(i mean outcome) on different currencies(not shure if it is, now checking).

Thank you for your answers, at least, now I understand how zombie mode works. Good luck.

[farkeytron]

Glad to help!