cgminer / USB Eruptor undervolt?

[CobaltBlueD]

I'll preface this
1. I'm stuck in the newbie section. Yea.
2. I don't have this problem on other machines but I'm solving for this particular machine because it is already on 24/7

I take a couple of USB Eruptors, stick them on a windows machine or a Mac, cgminer shows ~330Mh/s each. BTCGuild shows the cumulative correctly. I put them in the back of a Mac Mini, cgminer still reports ~330Mh/s per stick but BTCGuild is only showing ~370Mh/s in aggregate.

I'm assuming a USB undervoltage would show on cgminer as a reduced Mh/s within cgminer.

Aside from that, it's cgminer 3.3.2 on both the Macs I have tried. No GPU mining. Difficulty of 1. Nothing fancy in the configuration. Sticks are not on hubs, all direct to MB. No network differences. Happens right out of the gate before they get hot. No noticable difference in rejection or HW fail rate. Why would the 330Mh/s per stick not be reaching the pool?

Thanks in advance.

[ajw7989]

do the usb ports have enough power? Are you using a usb powered hub and how many erupters are you talking about. If they do not get enough power they might not work like they should.

[CobaltBlueD]

do the usb ports have enough power? Are you using a usb powered hub and how many erupters are you talking about. If they do not get enough power they might not work like they should.

No hub. Directly into MB. Power to USB appears fine. 2 Eruptors although one still shows the problem.

[dna2]

Hello, I had various issues with USB ASIC Miners and I found related to my Mac Book Pro. In order to solve them I had to use Windows 7 (on the same PC).
The biggest issue was the MH/s reported by the pool. In fact, while CGMiner was showing the expected one, the pool was showing me about half of the speed.

Finally, I found much more cheaper in terms of power usage (and comfort), to move everything to a raspberry PI.
Anyway, also with the RPI, I had to use a powered USB hub, as when I was connecting a third erupter, everything was becaming unstable...

Now I'm finally ok with 3 USB Erupters, my RPI and a 2.5A powered Hub...

Hope it helps
Kind Regards,
D.