Slightly unstable hashrates

[CryptoSquad]

Hi.

So when i overclock my 1070's to +1200 i get a very very consistent 188.47 hash rate using Ethminer. Every single line reads 188.74 without a single drop. But every 24 hours i get a crash in the miner so i went ahead and lowered my clock to +1000

What i dont understand is why this causes my hash rate to bounce rather than to be stable. Now i get a few lines at 178.2, then a few lines at 183.5, then a few lines at 188.74

I was expecting to have more stable lower figure than when i clocked at +1200.

Is what i am seeing to be expected?

Let me know.

Hope this makes sense!

Thanks

[CryptoSquad]

Shameless bump! Sorry, just keen to get my miner as stable as possible!

[HashashInc]

Did you apply same OC to all your cards? Could be because of each chip's asic quality. What temps are your GPU's at?

S.

[CryptoSquad]

Yep all cards have the same clock speeds

Temps are healthy between 55-65. All cards came from the same batch as have continuous serial numbers

Same thing happening on three different rigs.

As soon as I set clocks back to +1200 all goes back to a stable 188.74

[HashashInc]

Don't think serial number and batch has much to do with ASIC quality, i had a dozen cards with close serials from same batch a few months ago and they had an asic quality variance of about 25%, try tailoring the OC for each card i got much better results doing so.

S.

[CryptoSquad]

But if that was the case wouldn't it be inconsistent no matter what I set the clocks at?

[HashashInc]

Each card has his own core/mem ratio at which is more stable, maybe the OC you're trying messes up with one card (or all of them) causing instability?

S.