Since the 1660Ti's are generally low power GPUs, you can try and plug in a 6 PCIe into the 8 PCIe connection on the GPU and it will most likely still work. Most of my RX 470/570 have 8 PCIe connectors but plugging in a 6 PCIe still works on them.
You can verify this with a multi-meter and see if all the GND pins are continuous and not one of them is a sensor pin. You couldn't do this with older GPUs back in the 2013 days such as the R9 280X because they had a sensor pin and made sure an actual 8 PCIe was connected but they were power hogs at > 300 Watt per GPU.
I think the reason they do this is because many people have a hard-coded 8 PCIe connector with their PSU which doesn't separate and they wanted those PSUs to get used.
i can confirm that the gpus dont work with only 6 pins (even though the 1660tis get a large majority of their power from the risers). I didn't purposely test this out. I just didnt fully plug in the last two pins on one gpu and was wondering why it wasn't being recognized.
Anyways I no longer have any issue with plugging in my gpus properly since I contacted evga about providing extra 8+6 pin cables so im all good now.
Here is my current issue (which I posted in my most recent reply): ive had my rig up for a month (pretty stable for the past 2 weeks). So I have devoted my time to tweaking the OC settings so that I can extract a little more juice out of the cards. I had a few questions about my process and results.
For the past couple weeks I have been mining zcoin (mtp) on the trex miner. I have been overclocking with nvidia inspector.
I started by undervolting the cards to .8V and +150 core clock. (Well I bumped the core clock up by +25 until +175 caused imediate crashes).
I kept it at +150 and the rig ran for 15 hours straight without any gpus crashing. Then one gpu crashed. So I changed that gpu to +140 and the rest to +150. I ran the rig and now another gpu crashed after only 3 hours of uptime. Strange because that gpu was fine during the 15 hours uptime previously. Anyways, I lowered the clock on that one.
And I have been doing that process on repeat for about a week and a half. The rig will run fine for half a day but then I will check on it and see that a gpu had crashed. Ive had uptimes of 24+ hours and uptimes as low as 15 minutes. The good thing about trex miner is that it restarts itself (
https://imgur.com/a/qcknxQW) and the affected gpu is running like normal, its not "crashed", as in it is not working anymore. Trex keeps a running list of all the gpus that crashed during the current session so that helps me from having to scroll up to find any errors(
https://imgur.com/a/WHORZA7).
My questions: Am I doing this overclocking thing correctly?
I keep lowering and lowering the core clocks, seemingly without end. For my 9 gpu rig my core clocks are: +110,+110,+130,+150,+100,+100,+70,+100,+100. And still the rig will have a gpu that crashes once a day. And the weirdest thing is that one gpu will be running fine at its current clock for days and then it crashes for some reason. When will it end??
Why is it that one gpu ran fine for 24 hours at +130 but then couldn't run more than 2 hours at +120? Is the issue my core clocks or something else?
The gpus never "crash" so hard that they freeze the pc or even cause the gpus to be non responsive. Trex miner restarts its processes and all the gpus are operating like normal after restart, sometime for many hours afterwards. Other miner apps Ive used freeze or cause the pc to freeze when a gpu OC error occurs so thats neat. So should I even lower the core clocks or leave them high since the downtime is only for a few seconds? Is there any long term damage to the cards from the crashes?
Could this be a trex issue?
