Post
Topic
Board Mining support
Re: Hacking The KNC Firmware: Overclocking
by
bondus
on 13/02/2014, 10:51:13 UTC
1GHz baby!

I accidentally managed to turn on all 8 VRMs on my old 8VRM Jupiter.
Since they were all on and we can control the voltage with the tuning firmware I decided to try some more overclocking.

When running these with all VRMs on they have a base voltage of about 0.9V, so it had to be lowered in the advanced tuning page to get a reasonable voltage. -0.5V works fine.

Currents and temperatures are reasonable.

Total power consumption on the inside of the VRMs is 850W. I guess that will be 950-1000W at the wall. Since my PSU is only 1050W I do not dare to go higher.

The November units will be crazy once you get the tuning FW!


Very good.

A few quest:

- are you able you able to turn on all the vrms at will? If yes how?
- what oc settings are you using?
- any mod to get better cooling?



The accident that turned on the VRMs was that I loaded a November FW (0.99.2-E) onto an October Jupiter (bad idea). The machine did not hash with the November firmware, I realized my mistake and put back the proper October firmware. Once it started working again I saw that all 8 VRMs were running.

A pure accident.

My guess is that the November firmware has configured the GE VRMs as if they were the Ericsson units that are in the Novembers. Both VRMs talk the same SMBus protocol and are somewhat compatible. For some reason once they are turned on the October firmware do not turn them off again.

The whole process does not feel very safe.


I am using a 0x0271 setting.

Machine is totally stock, I haven't even opened the box.


When these machines were delivered they ran with all 8VRMs turned on at 0.9V. They ran like that for a couple of weeks when they were new with no major problems. It was not until FW 0.93 (or was it 0.95?) they disabled half of the VRMs.

A speculation to why they turned off 4 of the VRMs is that they ran out of components and had to manufacture boards with only 4 VRMs, and to make things "fair" for different customers they decided to run all boards with just 4 VRMs. They gimped the 8 VRM boards.
Another option is that it is unsafe to run with 8 VRMs. That there is something wrong with the boards.