Post
Topic
Board Hardware
Re: What causes the change in TH/s ?
by
macgyver007
on 15/02/2015, 16:04:22 UTC
OK i've thrown in a bit of a red herring in the fan speed. The fans were at auto when i was getting those mega numbers and it sounded like a wind tunnel in here and was mighty warm.
I set them to 10 after sitting next to the machines to take my screenshots and compose my post.

As for firmware I am using 2.6.7 and there is auto fan in there (see screenshots) :

Here's my Acis stat screen :



Tomorrow these are being moved into the cold room rather than my lounge, that should keep the temps down far more than this ambient room temp.

I'm also toying with spinning the fan around (test done) and sticking it in front of a portable AC unit thats in there running and seeing if having the fans run 10 on and it sucking in cold AC air can get some numbers crunched at a quieter level.
I was just trying to understand why when i'd not made any changed to the SP20 that the hash rate figures rose so high, after all the only thing i'd done was to change the pool it was mining.

I have asked ST direct via a support call if the hashing is linked to fan speed via voltage as if the fan speed being on nuts has the system draw more power and thus crunch the numbers higher then having a fan reversed sucking in cold AC air and the fans set low isn't going to do anything, surely then i'm just going to have a rig running at 1.4TH/s just really cooly.

Given what you've said about chips throttling due to heat, i'm actually hoping having these cool by the AC and sucking in the air that the hash rates will be even higher as the chips can continue to work harder without getting hotter. Either way we'll know tomorrow is ST don't reply today to that question via a ticket.

You should re-read my previous post and pay attention to the screenshot...I already commented on your firmware version and what to do about that, and notice that no A/C is going to bring your inlet temp down to 10C as in the screenshot I posted where my miners are cooled by Canadian winter which beats any A/C (its -40 today but miners are in 5C environment) Tongue

As I thought, none of your chips are even using higher than .73v (actually only 1 is and its not very happy about it as you can see in YELLOW) and the rest are borderline throttling /at their temp max.
the fan setting of 10 should not be used with stock settings under any means, and that is why the default is NOT 10
Remove the red herring from your setup and post back your results afterwards...and use manual selection to choose firmware 2.6.14 as I mentioned earlier 2.6.7 is buggy.
I don't see how you are testing for excessive cooling when you are cooking your chips  Huh
I think paying closer attention to the fine details will do a lot in helping you..if Im not mistaken you ended up with the SP20 buying them thinking they mine scrypt coins?